Brake Lines

Brake lines and corrosion seem to go hand-in-hand. Corroded brake lines will leak, which should be immediately apparent by a complete loss of hydraulic braking power, which is exactly what happened to me (luckily in a parking lot).  Replacing these lines can be problematic, mostly because they can be in difficult-to-reach locations, and the fittings are also most likely frozen by corrosion.

Here is how the brakes work: The brake pedal pushes a piston through the firewall. This motion is assisted by engine vacuum by the brake booster (which looks like a large cylindrical object on the firewall). The hydraulic pump (or master cylinder) is mounted directly on the brake booster, and also contains a reservoir for the brake fluid.

Brake booster and master cylinder

Two lines from the master cylinder connect to the hydraulic control unit.  This is also mounted on the firewall, and is responsible for distributing the hydraulic pressure to each wheel. Four lines come out of the control unit and each one goes to a wheel. Under normal braking conditions, all four wheels will receive equal pressure. Under heavy braking, the front wheels receive a higher pressure. The lines to the two front wheels are  fairly short and are sheltered by the engine compartment, so they are not likely to corrode. The rear lines run the entire length of the vehicle underneath, and are exposed to road salt and water. This is where most of the corrosion can be found.

Replacing brakes lines is not a difficult task by itself, but replacing the full length of a brake line can be cumbersome because they involve a lot of bends and turns. Therefore, most people only replace the corroded sections by splicing in a new line. Brake lines are made of rigid stainless steel, and can be easily cut with a rotating pipe cutter. A new connection requires a union. Before connecting a union, the lines have to be fitted with male fitting and the ends of the tubes have to be flared. The shape of the flare is important because it forms a perfect metal-to-metal seal with the female end of the union. Most importantly, the flare prevents the tube from separating from the fitting under high hydraulic pressures. Double-inverted flare is the most common flare shape, and it is the type used in the Kia Rio (this information is hard to find online, but it is specified in the Kia Technical manual). The fitting threads are M10 x 1 (metric). The best and most economical tool I have found for creating tube flares is the Eastwood on-car flaring tool for 3/16 brake lines. It is easy to use and compact, and works on the Kia. Although pre-flared brake lines are cheap to buy, the exact length needed may not match up with standard lengths sold in stores. I had to cut off one end of the fitting and redo the flare for the correct length.

Eastwood on-car flaring tool
Double inverted flare with a new male fitting
With the union connected

The problem was not solved even after splicing in the new lines. I was unable to bleed the brakes because all four bleed valves were completely frozen. These are small 8 mm screws, so they are very easy to round off.

Attempting to remove one of them resulted in a broken screw, so it had to be drilled out. That ended up damaging the threads in the caliper, so the whole caliper had to be replaced.  Also, both of the rear bleed valves were completely stuck and it was much easier to replace the entire brake cylinder rather than try to remove them. Even then, I ended up having to replace the brake lines leading to the cylinders because the connectors were complete frozen, and I had to cut the line to extricate the cylinder. While I was at it, it was also prudent to replace the rear brake drum, shoes, bearings and hub nut. All in all, a majority of the brake system was completely overhauled.

New brake line between the brake hose and the cylinder
Brake shoes, hardware and cylinder.

The hub nuts that hold the rear drum have to be replaced every time. These are not available at regular parts stores, and has to be ordered online. Instead of the cotter pin, these nuts are crushed to align with the slot in the axle (known as staking). This is best done with an air hammer and an axle nut punch tool.

Staked axle nut
Axle nut punch tool and air hammer

The final step is bleeding the brakes to remove all air in the newly installed lines. Since the entire system was empty, first the master cylinder has to be filled and bled. This is done by removing the two outgoing lines from the cylinder, and using plastic tubes to run the line back into the reservoir. Then pump the pedals to purge out air from the cylinder.

Bleeding the master cylinder

Bleeding the wheels requires a vacuum suction to pull the fluid through the lines.  This is best done with the Pneumatic Brake Fluid Bleeder with Auto-Refill Kit. Connect a compressed air line to create a vacuum (using the venturi effect), and the fluid can be pulled in through the bleed valve and collected into the tank. It is important to not let the fluid level drop in the master cylinder during this process to prevent air from being re-introduced into the lines. The kit comes with an inverted bottle which will automatically fill the master cylinder as the level drops.

A/C compressor

A/C systems are a bit mysterious, but super easy to understand and repair once you know what the different things do.  At the center of it is the compressor. It compresses the refrigerant and sends it to a spray nozzle, and then collects the drainage back into the compressor. The compressor squeezes the refrigerant gas into a liquid. This releases a lot of latent heat, so this gas-to-liquid phase transition takes place in what is known as a condenser. It looks exactly like a radiator so that most of the heat can be dissipated. The spray nozzle is known as the expansion valve, and is mounted on the firewall, usually on the passenger side. As the liquid refrigerant is sprayed, it will evaporate and cool. Therefore, this process takes place in the evaporator core, which is inside the passenger compartment attached to a blower fan.

My compressor failed catastrophically one night. It totally seized up, and the drive belt burned up in a cloud of smoke.  Whenever the compressor seizes up, metal shavings will end up into the downstream refrigerant lines. This means most of them will be stuck in the condenser and in the expansion valve, so these components should be replaced as well. Without it, the new compressor is almost guaranteed to fail (ask me how I know). In order to remove the condenser, the radiator and its cooling fan has to be removed. There are actually two cooling fans. The fan at the front of the vehicle cools the condenser, and the rear fan cools the radiator. After removing the rear cooling fan, the coolant has to be drained from the radiator and its hoses disconnected (including the transmission fluid coolant lines). The condenser is sandwiched between the radiator and the front fan.

Removal of the backside fan
Radiator removed
Old condenser
New condenser
Compressor ports taped off to prevent debris

During installation, it is best to seal the compressor ports with some tape to prevent debris from falling in. Even small amounts of debris could be catastrophic for the rotating surfaces of the compressor. The new compressor usually comes with the correct amount of refrigerant oil, but the condenser may not.

The expansion valve is relatively easy to remove and replace. All o-ring seals should be replaced at this time as well.

Old expansion valve on the firewall
Expansion valve removed
New expansion valve installed

Then the system is evacuated with a vacuum pump. Because the hole in the expansion valve is small, the system has to be pumped out from both the high and the low pressure sides. Additionally, since the refrigerant lines in the condenser are also extremely small, a long pump duration is necessary to pull all air out of the system- at least about one hour. Unfortunately, the vacuum gauges that comes with standard A/C manifold systems do not have enough sensitivity to show small changes in vacuum levels. It is not easy to tell if the system has reached its lowest vacuum level, or if it is still pumping. A useful trick is to pay attention to the sound of the vacuum pump when the isolation valve is turned on and off. If the system has reached its lowest vacuum level, and there are no leaks, there should be no change in sound. Even a small change in sound will indicate that there is a small flow coming from the A/C system. It may be hard to believe, but this process is far more sensitive than relying on the pressure gauge.

The Rio takes 20 ounces of R-134a refrigerant. A standard bottle/can contains 12 ounces, so a little less than 2 bottles is needed. Walmart sells these for less than $5 each. The standard technique is to disconnect the vacuum line from the pump after the evacuation, connect the refrigerant bottle, and purge the line with refrigerant by letting air out through the small valve located at the manifold. I was not happy with this technique because after spending all that effort to perfectly evacuate the system, we can still end up introducing air or moisture. Here is a better way: Remove the valve at the manifold and connect a separate yellow refrigerant charging hose to that port. Connect the refrigerant bottle to the other end, but leave the bottle closed. When you evacuate the system, it will create a vacuum everywhere up to the refrigerant bottle. When evacuation is complete, close the valve at the vacuum pump, close the high-side (red) valve, and open (or pierce) the refrigerant bottle. This will start pulling refrigerant from the bottle and into the A/C system. When one bottle is empty, close the valve at the low side (blue) inlet to isolate the A/C system, connect the new bottle, and run the vacuum pump again to evaluate the hoses. Evacuation should happen fairly quickly because you are only evacuating the hoses. Then start filling from the second bottle.  Stop short of completely running the second bottle empty because you only need another 8 ounces from the second bottle. Alternatively, you can use a weighing scale, but I have not been able to get a reliable reading from the scale with the hose still attached to the bottle.

Ignition key switch replacement

My Kia Rio would sometimes not turn over when starting, and it would take a several attempts turning the key to get started. Even when it did turn over, the cranking power seemed pretty low, almost like it was a bad battery or a failing starter motor. After replacing the starter motor and battery and seeing no improvement, I traced the problem down to the ignition key switch. This is hardly ever talked about, so I assume it is a rare problem. Fortunately, it is relatively easy to fix.

The ignition key switch contains two components, One part is the lock cylinder where the key goes into, and the second part is the electrical switch. It is a simple rotary style switch. The start position was not making good contact, which was the cause of my problem.

The first step was to remove the top and bottom covers around the steering wheel. The bottom cover is held by three screws and the top cover is just snapped into the bottom cover.  The rotary switch is a white plastic part attached to the end of the lock cylinder. Removal requires access into some tight spaces and a right angle screw driver would be needed. The lock cylinder does not have to be removed.

The same wire bundle also goes to a separate push button switch that attaches to the side of the key slot. This is the switch that senses the key in the slot and makes the beeping sound.

After replacing the key switch, the starting performance was noticeably better. It had the same effect as if a dying battery had been replaced.

Starter Motor Replacement on the 01 Kia Rio

The starter motor in the 2001 Kia Rio is in a very awkward position. It is on the bell housing below the intake manifold pipes, and held by three bolts. The two upper bolts can be accessed from the engine compartment from the driver side. The air filter box and the air intake pipes have to be removed to gain access to these bolt. Even then various socket extensions will be needed.

The lower bolt is best removed from under the vehicle. First, the intake manifold brace has to be removed after taking off it’s four mounting bolts. With the brace out of the way, the starter motor becomes easily accessible from below.

Location of the starter motor under the vehicle
Intake manifold lower brace
Starter is much more accessible after removing the intake manifold brace

The starter motor has to be gently lowered to get access to it’s electrical connectors.  There are two electrical connectors – a heavy positive cable that comes directly from the battery, and another small spade connector for the control signal.  There is no external starter relay in this vehicle. It is built into the starter motor.  It is important to disconnect at least one terminal of the battery before working with the starter. If the positive wire accidentally comes in contact with the vehicle, it will short the battery and start a fire. After disconnecting the wires, the starter can be taken out by lowering it. There is no way to take it out from the engine compartment.

When reconnecting the wires, it is important to remember where the power cable goes. There are two bolts and they are not marked. One is ground, and it is internally connected to the metal body of the starter. The positive cable from the battery should go on the second bolt.  Do not connect the positive cable to the ground bolt for obvious reasons. Additionally, a dirty connection can cause the starter to run poorly. Due to the difficulty accessing the starter motor, the connectors should be thoroughly cleaned before installing the starter back into the vehicle.

The left bolt is for the positive cable, and right bolt is internally grounded so do not connect anything here.

Tapered Roller Bearings

The 2001 Kia Rio uses two tapered roller bearings. They are different than the majority of bearings. Most shops don’t seem to know how to replace them correctly, or even care to refer to the Kia service manual.  I went through six bearings in 24 months, and four of them were done by the Castrucci dealership in Dayton. After spending over a thousand dollars on shoddy work, I decided to do it myself. It took two weekends, but my wheel bearings have never run this smoothly in years.

Principle of Operation

The spacer is the most critical item in the wheel bearing. This is how it works: when the axle nut is tightened, both the outer and inner bearings will be pulled towards their races. If the clamping force between the bearings and races is too high, the bearings will be under excessive compression. The typical torque applied to the axle nut is about 150 ft-lb. This is sufficient to completely lockup and crush the wheel bearing. This is why there is a spacer. The spacer takes up most of the clamping force, leaving the right amount of force to hold the bearings against the races.  In other words, even with 150 ft-lb on the axle nut, the bearings will be just snugly held against the race, and not with a crushing death grip. This process is known as preloading the bearing.

The spacer has to be the correct length to make this happen. There is no one size fits all. The exact length is specific to each bearing and each steering knuckle. It can only be determined with the steering knuckle on the bench (and not in the vehicle). Kia recommends checking the preload and spacer every time the bearings are disassembled. There is even a technical service bulletin that says reports of repeat wheel bearing failures were due to improper installation. Surprisingly none of the Kia shop technicians I spoke to are even aware of this bulletin.

How to set this preload is described later in this post.

Removal of the Steering Knuckle

Though it sounds ominous, removing the steering knuckle and wheel hub is actually quite easy – easier than changing the engine oil because you don’t need to crawl under the vehicle.

First, the axle nut should be loosened. This is much easier to do with the wheel firmly against the ground. So, do this before raising the vehicle. Then the brake caliper and rotor need to be removed.  The caliper is held by two bolts, and the rotor is held by two Philips screws. Once the rotor is off, the wheel hub should be visible.

Next, the steering knuckle has to be removed. This is what holds the wheel hub, bearings and races. It is attached to the strut with two large horizontal bolts. There are two other ball joints  – one on the lower control arm, and one on the steering tie rod.

The steering tie rod ball joint is held by a bolt, castle nut and a cotter pin. Once these are removed, the rod end can be separated by tapping the bolt from below with a mallet. Be careful not to damage the grease boot around the ball joint. Once the steering tie rod is removed, the wheel hub can be steered by hand making it easier to access the back side.

Next, remove the two horizontal bolts and nuts that hold the steering knuckle to the strut. Once these are off, the steering knuckle and can be tilted outwards and the axle can be tapped out of the hub splines.

Next, remove the bolt and nut on the lower backside. This bolt acts like a locking nut for the bottom ball joint. Then the steering knuckle can be simply lifted out of the lower ball joint.

The last item is the speed sensor (only on the passenger side), which is held by one bolt. But it may be frozen in place, and may have to be tapped out with a mallet from underneath.

With the steering knuckle on the bench, the wheel hub can be knocked out with the right sized socket and a hammer. Then the two wheel bearings and the spacer should simply fall out.



Inspect the wheel hub for damage. Mine had a lot of gouges, another evidence of incorrect preloading by the previous mechanic, so clearly it had to be replaced. It is a cheap item, so it is best to replace it if you get this far into the process.


Clean the steering knuckle in a solvent bath so it is easier to work with.

The next step is to remove the races. This can be a bit tricky. It comes off easier if the body is heated with a propane torch to slightly expand it. Then go around the rim and knock the races with a screw driver and hammer. It takes a while, but it will come off eventually.

Then install the new races. Make sure the races go in straight and not tilted. A bearing installer kit is extremely useful here. Here is a very handy trick. Place the new races in dry ice for a few minutes (you can buy dry ice in many grocery stores).  This will shrink the races enough to simply drop them into the hole.

Setting the Bearing Preload

This is a topic of much confusion, and most mechanics (including the Kia dealership mechanics) don’t seem to know how to do this properly.  Typically they send the whole steering knuckle to a machine shop. This is where the problem begins. The machine shop will simply reuse the existing spacer assuming that is the correct size for this vehicle. My bearings failed six times within 24 months, and four of them were done by the Kia dealer. Don’t trust anyone to do this correctly, and you don’t need a machine shop either. Do it yourself and save thousands of dollars in wasted repair cost.

The basic idea is to find the correct spacer length that will give the specified rolling friction for the specified axle nut torque (typically 150 ft-lb). If the spacer is too short, the bearings will be under too much compression. If the spacer is too long, the bearings will have too much play. Both will result in premature failure of the bearings and races. The difference between too short and too long can be as little as 4 mils (100 micrometers). Every bearing and race is slightly different, which is why reusing the old spacer is guaranteed to cause problems.

The correct spacer length is determined by assembling the bearings and spacer into the steering knuckle on the bench and measuring the rolling friction. Of course, since the real axle is in the vehicle, and the wheel hub is not yet installed, we need something else that can simulate their function. There is a special tool from Kia which costs $90 (part number 0K130 331 016), but this is really not necessary. Here is how you can do this without the special tool.

Find a short metal tube (aluminum is fine) 38mm in diameter, and roughly 1” in length. It may be easier get a 1 ½-inch diameter tube and lightly sand it down to 38mm. The inside hole diameter of the tube should be at least ½”, but larger is ok as well. The purpose of this tube is to keep the spacer aligned to the wheel bearings. In the vehicle, all three parts ride on the same hub shaft, so they are automatically aligned, but on the bench we need this tube to do that job.

The bearings and the spacer should slide snugly over this tube.

With the new races already installed, clamp the steering knuckle on a vice. Install the two bearings, spacer and the aluminum tube into the steering knuckle.

Then select a proper sized puck from the bearing installer kit to hold the bearings on one side of the steering knuckle. Slide a long ½”-diameter bolt through the whole assembly. Place a second puck on the other side, and use a nut to clamp everything in place.

Tighten the nut, lightly at first, and measure the rolling friction. This can be done with a long wrench and a fishing scale. The rolling friction should be between 2 and 10 inch-lb. When measured 4-inches from the bolt the force on the scale should be 0.5-2.5 lb. This is a low enough that the assembly should turn easily by hand. If it is too tight, that means a longer spacer is needed. The goal is to incrementally torque the nut to 150 ft-lb while keeping the rolling friction between 2 and 10 inch-lb.

Since the spacer length is determined by trial and error, you need many different sizes on hand. This could be a problem because there are 21 different sizes from 6.285mm to 7.085mm. Each one costs about $5, and they are only available through a Kia parts distributor (even they will have to special order it, so be prepared to wait a few days). This brings up a question – how are they repairing wheel bearings if they don’t have all the spacers in stock, but I digress.

Spacer selection table

Once the correct spacer is found, disassemble everything from the bench, and install the bearings and seals with plenty of lithium lubricant. The hub should be pressed in carefully because it is a tight fit. Use the bearing installer pucks with a long bolt to pull the hub into the bearings. Then install everything in the vehicle and tighten the axle nut to 150 ft-lb. The rolling friction should automatically reach the previously set limit of 2-10 inch-lb. Of course, you can’t verify the preload at this stage, which is why it is important to set the preload on the bench. This is the factory specified procedure, and if you do it this way, you will not have any problems with wheel bearings.

Here is the Chapter from the Kia Manual on Front Hub Axle Repair Procedures

Idle Air Control Valve

The vehicle (2001 Kia Rio) was having rough idling and stumbling, and every time this happened the code was P1166 (non-specific fuel related problem). Rough idling could be due to a sticking idle air control (IAC) valve. The IAC is easy to remove and cheap to replace, but a sticking valve can also be easily repaired. After doing this, my idle problem was solved.

The IAC is an electrically actuated valve mounted to the throttle body, slightly above the throttle butterfly valve. If you look down the throttle body, there are two holes on the side walls. One is for supplying air to the crank case, which returns through the PCV valve and then goes to the intake manifold to consume unburnt fumes from the crankcase. The second slightly larger hole goes to the IAC valve. Air flows through the IAC valve bypassing the main butterfly valve, and returns to the intake plenum slightly under the butterfly valve. The valve contains a small metal plate that slides back and forth to control the size of the opening. The neutral position of the plate seems to be in a slightly open position.

The two mounting screws are in a tight spot and required the use a right angle driver to remove them.

The valve connector has three terminals which are labeled on the body. #3 and #2 opens and closes the valve. If you apply 12V to #2 and ground to #3, it should open the valve fully. Mine was frozen in place even after repeatedly cleaning with Brakeleen and WD-40. I had to force the plate to open with a screwdriver. Once it started to move, more soaking and cleaning freed the plate and it started to move smoothly.

The #1 wire is the feedback from the IAC, like the throttle position sensor.

The old gasket has to be scraped off and a new gasket should be used when reinstalling the IAC valve.

Location of the idle air control valve
Looking down the throttle body
Throttle body with IAC removed
Actuator plate inside the IAC valve

Rebuilding the cylinder head in a 2001 Kia Rio

Cylinder heads are very susceptible to heat. A single overheat incident due to a coolant leak or blower fan failure can cause the cylinder head to warp. That is exactly what happened in this case, so a rebuild was necessary. This is not a small job. It took 2 months to do this, but admittedly most of that time was spent waiting for parts or tools to arrive. After completing this work, the vehicle was running like it was new, absolutely quiet and smooth. It was a satisfying end, and I learned a lot of things about engines during the process.

Engine compartment before starting the work

Tear Down

This is not a complete how-to list, but only the note-worthy items are listed.

  • Although not absolutely necessary, removing the radiator, windshield washer reservoir and battery will create a lot of extra room and will make the work significantly easier.
  • Use Ziploc bags to organize the nuts and bolts and to prevent losing them.
  • Take lots of photos before things were dismantled and wires were removed, so that they can be reconnected without too much trouble.
  • The intake manifold is not easy to remove. In addition to the manifold bolt, the assembly is also held by two extra bolts on a lower horizontal support plate bolted to the frame under the engine. These bolts are not visible from the top, and it will not be immediately apparently what is preventing the manifold from moving.
After removing the valve cover gasket and exhaust manifold
  • Removing the water pump pulley is very tough due to the tight space. There is not much space even for a strap wrench. The easiest method by far is to loosen the bolts while the drive belt is still on and under tension (duh, isn’t this is the ideal strap wrench?).  During installation, just hand tighten the pulley bolts, then install and tension the belts, and then finally tighten the pulley bolts.
  • Get a few Sunex long-arm ratcheting combination wrench. Despite its high price, it will make reaching bolts in difficult areas much easier.
  • Power steering pump and alternator are mounted with a bolt in a sliding slot to allow adjustment of the belt tension. But grime build up may prevent the mounting bolt to slide easily in the slot. It may be easier to remove the entire mounting plate.
  • The head bolts will require 12mm 12-point deep sockets. These sockets can be bought individually at Lowes instead of buying a whole set from auto parts stores. The removal pattern is important, but if the cylinder head is warped anyway, it doesn’t really matter. Once all the bolts are off, it should be easy to simply lift the head off the block. It probably weighs about 30 pounds.
After lifting the cylinder head off the engine block
Removed cylinder head
Cleaned cylinder head after servicing it at the machine shop

The warp was 0.010” on the cylinder head and 0.002” on the deck. The deck was within spec, but the head was significantly warped. An automotive machine shop can fix this easily. The cost was $120 for machining, cleaning and pressure testing. It came back totally clean and dry.

Cleaned deck, pistons and intake manifold

A strong solvent is necessary to clean the deck. “Aircraft Remover” works well. A blade is useful for scraping the old gasket off the surfaces. Do the same for the intake manifold. The pistons can also be sprayed with the same stuff and wiped off.

Rebuild Kit

The parts needed for rebuilding the cylinder head are:

  • Head gasket set – in addition to the main head gasket, a rebuild kit will also include all the other gaskets, such as for the intake and exhaust manifolds, water pump, thermostat etc.. New valve guide seals will also be included.
  • Head bolt set – these bolts should not be reused because they get stretched during installation.
  • Water pump – the water pump in the Kia Rio is in a tough place, and there is no better time to replace it than during a head rebuild.


C clamp tool
Lisle valve keeper insertion/removal tool
Valve stem seal removal tool
  • This is a good time to also replace the valve seals, even if they had passed the leak test. Removal of the valves requires a valve compression tool. The generic C-clamp tools won’t work because the Kia valves are recessed inside a hole with very little space around it.
  • The Lisle valve keeper tool is a better choice. It works for removal as well as installation, but it does require a lot of force to get the keepers to snap back in place. This youtube video made it look really simple, but I had to struggle a great deal. Some recommended using a hammer, but after trying it, I didn’t like the idea of using a hammer to compress a spring (not to mention it didn’t work most of the time). I ended up using a a wooden bar across the handle to give it extra leverage to push down on it. That made the process quite a bit easier.
  • Removal of the valve stem seals also require a special tool. Pulling it with pliers did not work, and even with the special tool it took a lot of wrestling to get the seals off.
Exhaust valves
  • The exhaust valves had a lot of white buildup. They were impossible to clean with a brass wire brush. So all of the valves were sent to a the machine shop for cleaning and refacing. Cost was just $2 per valve, and they came back the same day. They used a heavy duty steel wire-brush to clean the valves, and a precision grinder to polish the sealing face along the edges. Most of the advice on the internet seems to recommend against steel and to use brass. But these valves are made of hardened steel, so it is unlikely to get damaged from a steel brush.
Valves before cleaning and refacing
Valves after cleaning and refacing
  • The valve stems should be fully lubricated with oil before inserting them into the holes. The next step was to lap the valve seats. This requires a valve lapping tool and lapping compound. When reading about it, this process sounds a bit mysterious, but it is really simple. The lapping sound changes from a low-pitch grinding noise to a high-pitched squeaky sound, which is when the valve should be lifted and the process repeated a few times. Then thoroughly wipe the area of all traces of the lapping compound. The idea behind lapping is to make the contact areas smooth but lightly grooved concentrically so that they can seal well.
Wooden bar for the pushing against the keeper-installation tool
After installing the valve springs and keepers

Hydraulic Lash Adjusters

Hydraulic lash adjusters
  • The HLA (Hydraulic Lash Adjuster) are the silvery cylindrical buckets that slide through the holes and push on the valve stems. These are most easily inserted and removed with a magnetic pickup tool. I had assumed these were just cylindrical blocks of metal and hadn’t given them much thought, until I installed the camshafts and discovered to my dismay that all the valves remained open by random amounts with no relationship to the cam lobes. After some reading, I found out that the HLAs are not just pieces of cylindrical blocks, but are miniature oil reservoirs. They are designed to smoothly ride on the camshaft lobes to keep the valves continuously in contact with the camshaft. If there is even a small gap, it would result in a hammering action that could cause the camshaft to erode, and also make the engine noisier. The HLAs contain a spring-loaded piston and a check valve to hold pressurized oil inside. During installation they should contain air instead of oil. This makes them compressible when pushed by hand. When the cam starts turning, the air in the pistons will be driven out and oil will be sucked in. As it fills with oil, the check valve locks in the oil. Since oil is a lot less compressible than air, the HLAs become stiff. This makes the piston push against the valve stem instead of compressing. It is a very clever design because the HLA automatically adjusts its thickness to compensate for the play between the cam lobes and the valve stems. Without these HLAs, we would need precisely machined spacers, and the pieces may have to be re-machined periodically to adjust for changes in the cam lobes. The only problem with these HLA’s is that whenever the camshaft is removed, the pistons inside the HLAs will automatically inflate and will fill with oil from the surrounding area. Once they expand, they cannot be put back in service without draining the oil out first. Doing so might cause the valves to malfunction. The Kia is an interference engine (meaning the pistons can contact the valves if the valves are open when the piston is at the top dead center) so this is an important consideration.

All of my HLAs were full of oil and were solid as a rock. HLA’s are definitely reusable, and it can be pretty expensive to replace all 16 of them. The pistons can be pulled out with a long-nose locking vice grips. Regular pliers, even needle nose pliers didn’t work.

Removing the piston assembly out of the HLA body

I mounted the HLA on a bench vice (with towels) and locked the vice grip and pulled while turning. It slips a number of times, but eventually the piston pops out. It’s a matter of patience and technique. Once it pops, oil pours out that looks like black tar. This is oil that has been locked in there for ten years or more. Once you know the technique, it will take less than five minutes to disassemble all sixteen HLA’s.

After removing the piston assembly from the HLA body
  • The internal parts of the HLA’s piston assembly can be pried apart easily. It contains the piston itself, a check valve and a small spring. The check valve can also be disassembled quite easily by prying out the frame that holds a steel ball inside a hole. I cleaned these pieces in Brakeleen, oiled them and reinserted them back into the HLA body. The parts should be lubricated with oil, but the piston cavity should not be filled with too much oil – otherwise it won’t compress. The HLAs initially need to be compressible in order for them to inflate to their proper heights.
Dismantling the piston
HLA body, piston, spring and check valve
After installing the HLAs


Oiled cams in place
  • One camshaft is a bit longer and has an extra piece at the tail for triggering the camshaft position sensor. It is also best to check that this tail piece is securely screwed in before putting the camshaft in. The front oil seals should also be replaced, and should be included in the head gasket seal kit.
Cam carrier
  • Before installing the cam carrier, sealant (Ultra Grey) has to be applied in a bead, avoiding the oil pathways. The tightening torque calls for 10 ft-lb, which is pretty low for a torque wrench, so it may be ok to just use a hand wrench.

    Water Pump

    • This is also a good time to replace the water pump because it is a cheap item. But the water pump turned out to be one of the most difficult tasks. It required the removal of both timing belt rollers, and four mounting bolts. These bolts are all hidden and hard to locate due to the tight space. It would have been impossible to identify these bolts without comparing against the new water pump.
    • Before the water pump could be taken out of the vehicle, the water inlet pipe had to be disconnected. But its bolts were hidden behind the power steering pump. So that had to be removed. But it’s long mounting bolt could not be pulled out without interfering with the nearby brake lines. So the brake lines’ brackets also had to be removed at two locations to allow them to be moved a bit. Then the power steering pump was removed and moved out of the way without removing any of its hoses.
    • Even with the power steering pump out of the way, the lower bolt on the water inlet connection was still blocked by a bunch of things – the oil dip tube, the power steering pump’s mounting bracket and the AC compressor. Removing the dip tube and the power steering pump’s mounting bracket would have given sufficient access, but the dip tube would not budge, and also one of the bolts on the steering pump bracket had been stripped by someone before. This is probably because the spacer used for the steering pump was blocking one of those bolts. Unlike most spacers, this one is inserted into the bolt hole, so it needs to be tapped out. The last mechanic who worked on this probably could not figure out how to get this spacer out so he must have tried to unscrew the bolt behind it without adequate access and ended up stripping it.
    View of the new water pump with the timing belt rollers and tensioning spring re-attached.
    • After removing the old water pump, I replaced it with a new pump. The mating surfaces were cleaned. The manual says not to use any sealant, but a tiny bit of water pump sealant helps to hold the gasket during mounting, especially for this case since the water pump is in such a difficult position. I practiced using the old water pump how the insert it into position without dinging the mating surfaces. Then gasket sealant was applied on both sides of the paper gasket very thinly and glued it to the water pump. Mounting was fairly easy after that.
    • Mounting the intake water pipe was also easier with the AC compressor and its mounting bracket out of the way.
    • Now the AC compressor, power steering pump and the brake lines could be reinstalled.

    Timing Belt

    After removing the crankshaft bolt
    • It would be foolish to not replace the timing belt during this rebuild. This requires the removal of the crankshaft pulley, crankshaft bolt and the timing belt guide plate.
    • Removing the crankshaft bolt was tough because the shaft is free to spin. Even an impact wrench did not work. It turned out that the simplest process was to remove the crankshaft position sensor (CKPS) and insert a screwdriver to jam the flywheel to lock the shaft while turning the bolt.
    Jamming the flywheel through the CKPS hole
    Crankshaft bolt
    Timing belt guide plate after removing the pulley
    Timing belt sprocket
    • In order to take the old belt out, the engine mount on the passenger side has to be removed. It was an easy step that took less than 15 minutes. I removed the bolt that holds the large rubber bushing and the two vertical mounting bolts while the engine was supported from the bottom near the oil pan drain plug with a hydraulic jack. Then the old belt out was taken out, and the new one put in.

    Mounting the new cylinder head

    • The first step was to move all the cylinders to the mid position. Then  all the threaded holes for the head bolts were cleaned by spraying Brakeleen into the holes and blowing it with compressed air. Then a copper spray sealant was applied to both sides of the head gasket. This was a bit messy, and parts of the sealant peeled off when I flipped the gasket over to spray the other side. The gasket only goes one way on the engine deck. There is a tilted oil hole at the rear center of the engine deck which will only align with the gasket in one orientation.
    New head gasket
    New head gasket after applying the copper sealant
    Head gasket on the deck
    Cylinder head mounted and torqued to the engine block
    • Placing the cylinder head was not difficult. It went in pretty easily into the alignment holes with only a small adjustment after it was placed. The head bolts were greased and lightly tightened. The sequence is specified in the service manyal. Two bolts are shorter than the others and they must go near the timing belt. The first step is to torque them to 36 ft-lb, loosen them all in the reverse order, and then re-torque them to 18 ft-lb. This 18 ft-lb seemed awfully low, until you make the required 90-degree turn afterwards, which raises the torque to about 50 ft-lb.
    New water bypass tube. The original color is green but the old one I had was blackened over time.
    • The water pump inlet has a split fitting – one is the return from the radiator and the other is the return from the heater core with a small branch coming from the air intake box. The piece that carries the return from the heater core and air box is a long metal tube that runs under the exhaust manifold and around the engine. This fits into the split fitting with an o-ring seal, and is only held by a bracket almost a foot away from the fitting that goes onto one of the exhaust manifold screws. It is a very strange fitting. I realized that that the bracket had been accidentally bent when removing the exhaust manifold. It was easy to unbend it, but the exact shape of the bracket in relation to the fitting is probably important, so I bought a new one from the Kia dealer for $35.
    • Before installing the timing belt, the pulleys need to be installed on the cams. The intake and the exhaust pulleys are exactly the same and have the same markings, so it is important to mount them correctly by examining the cam lobe locations and the firing sequence of the cylinders. The cylinder firing sequence is 1-3-4-2 where cylinder #1 is closest to the timing belt.
    Overhead dual cam locking tool – this did not fit on the Kia Rio. The center coupling nut was too long, and it is not easy to replace it because it has left and right hand threads on opposite ends of the nut.
    • Installing the timing belt was also more difficult than I had thought. The belt was extremely tight, and I could not get it on the sprockets. The only way was to remove the tensioning roller. That meant I also had to remove the water pump pulley and the crankshaft pulley. Having it done it once, it was easier the second time.  Even then, I could not hold the camshafts in the right place due to the tension in the valve springs. So I bought the “Lisle dual overhead camshaft locking tool”, but it was too large and would not fit on this vehicle. After many tries, here is a trick that worked for me. After first lining up the crankshaft, I used a wrench to turn the exhaust camshaft to its correct position. While holding the wrench, I pulled the belt and slipped it on and used a cable tie to prevent the belt from slipping off the exhaust cam sprocket. Then I did the same with the intake pulley. To insert the tensioning roller, I used the wrench to turn the exhaust camshaft counterclockwise. This tightened the belt on the exhaust side and loosened it on intake side, which gave it enough slack to bolt the tensioning roller in place. Putting the tensioning spring back on was also tricky due to the confined space. I inserted a cable tie through one of the spring windings and pulled it from the opposite end to stretch the spring and slip it on to the post. The whole thing was surprisingly difficult for a simple timing belt installation.
    The spring connected to the tensioning roller
    This is the opposite end of the spring, near the second roller. It had to be stretched by connecting a cable tie to pull it and slip it on to the post.
    • The valve cover had a lot of grime inside and out, and I had to soak and scrub with Brakeleen several times. The head gasket kit also came with a new valve cover gasket.
    • After everything was re-assembled, and all the wiring plugged in, I squirted some oil into each cylinder through the spark plug holes and put some rag into each hole to prevent oil splash. I also put oil into the oil filter before screwing it on. After filling the engine with fresh oil, I removed the fuses for the fuel pump and the injectors and cranked the engine for a minute. The oil pressure warning light on the dash should extinguish by then. Then I filled it with coolant.
    • Then I reinserted the fuses, installed new spark plugs and started the engine. To my pleasant surprise, it started right away without any hesitation. There was lots of smoke through the exhaust and through the front, but it seems to run fine. The smoke kept going for a long time, and I was concerned if something was wrong, but it went away after about an hour. The temperature was fine, and the radiator fan was cycling normally. It also sounded smoother than before.
    • In the radiator cap, I could see small flakes of copper paint coming through, presumably from the head gasket. It was not too much to be concerned about.
    Everything assembled and running great