Rear Shocks

Whereas the front suspension has a strut which is a single unit consisting of the shock running inside the spring, the rear suspension contains the spring separate from the shock. Replacing the rear shock is relatively easy. It is held with two bolts at the top attached to the frame body, and one bolt and bushing at the bottom attached to the wheel unit.

Old shock absorber unit with rusted cylinder housing

The lower bolt goes through the bushing on the shock and screws into a welded nut. Since this is fully exposed to the elements, the everything was corroded, and it was hard to even notice that the nut was a welded nut. The bolt just wouldn’t budge, even with an air impact wrench.

Lower bolt and bushing

I had to pull out my oxyacetelyne torch and heat the nut until it was cherry red. The rubber inside the bushing was also starting to burn. Using an impact wrench while the whole thing was still hot did the trick in removing the bolt.

Acetelyne torch

In comparison, the upper two bolts were a lot easier to remove. However, the threads are not very deep, and it is easy to strip the threads.

Upper bolts holding the shock
Old and new shock

Strut Replacement

Replacing struts is one of the simplest jobs one can do on the vehicle. The strut is a single unit that contains the suspension spring coil and the shock absorber (dampener). The spring is kept compressed under tremendous pressure inside the strut. It is like a loaded gun. Therefore, it is not worth the trouble to disassemble the strut or attempt to replace its internal components. It is much easier to buy the whole strut. The cost of a complete strut for the front wheels was only $75 each.

Assembled strut unit

Two horizontal bolts hold the steering knuckle to the strut. These are easy to remove. The hardest one to remove is the sway bar arm that is attached to the strut. It is a ball joint, and the bolt needs to be held from the opposite side with a wrench while turning the outside nut. Its a bit tricky and it is easy to strip the nut, but it does come off eventually.

Steering knuckle and sway bar attached to the strut

Next, the top of the strut has to be removed from inside the engine compartment. The center nut should not be loosened, as it holds the compressed spring. Once the two outer nuts are removed, the strut simply falls off from the bottom. Before doing this, the brake hose and the speed sensor wire have to be removed from their harnesses attached to the strut.

Strut tower attachment inside the engine compartment
After removal of the strut

Here are the old and new strut. The left and right sides are different, so it is important to match them up correctly.

Old and new strut assembly

This is with the new strut installed

With new strut installed.

CV axles and ball joints

The biggest challenge in replacing the CV axles is the removal of the old axles. The shaft is locked inside the transmission with an expanding C-clip. To release the shaft, it has to be pulled sharply to make the C-clip compress and slip out of its retaining groove.


First, the steering tie rod has to be disconnected, and the wheel hub has to be removed from the lower control arm. A prybar could be used to remove the axle from the transmission, but a more effective method is a slide hammer. This can be done as follows: Separate the inner CV joint by removing the metal strap that holds the rubber boot and then pulling the joint apart. This will leave just the cup attached to the transmission. Clean all the grease inside the cup.

The inner CV cup

The tool we need is a slide hammer with a vice grip attached to the end. Most slide hammers come with a threaded attachment. As long as we find a vice grip with the correct screw size, it can be directly attached to the slide hammer.

Vice grip attached to a slide hammer

Tightly clamp the vice grip to the cup wall. A couple of sharp pulls on the slide hammer should release the shaft from the transmission. If that doesn’t work, an alternate method is to drill two holes on the sidewalls of the cup, insert a bolt and attach the slide hammer at the center. Luckily, in my case the vice grip method worked for both axles.

Vice grip attached to the inner CV cup

The shaft seal should be replaced any time the axle is removed. This will require a seal puller. Installing the new seal can be done with a wooden block and a hammer, but a bearing driver comes in very handy.

Shaft seal
This is what the transmission input looks like with the shaft seal removed.
With the shaft seal

Installing the new axle is a lot simpler. It can be simply inserted into the transmission and gently tapped with a hammer to snap the C-clip in to place (with the axle nut attached to protect the threads).

Old vs new axle

The grease boots on my lower control arm ball joint were torn, so this was a good time to replace it. The arm is attached to the frame as well as to the stabilizer bar. There is a welded nut inside the frame that the bolt screws into. At the other end, the stabilizer bar runs through the control arm with two bushings on either side.

Removal of the lower control arm
Old and new lower control arm
With the lower control arm removed

This is also a good time to replace the outer steering tie rod end. There is a jam nut that locks the position of the tie rod. This is a critical part that determines the alignment of the front wheels, so it must be replaced in the exact same position. Even then a new alignment job may be necessary.

Old and new tie rod end
With the new rod end and control arm installed

Here is a photo of all of the items that were replaced. It includes brake pads, axles, seals, lower control arm and tie rod ends.

All the parts that were replaced

Transmission Fluid

I was losing transmission fluid. I noticed this while driving uphill – the climb power just didn’t feel right. The Kia calls for SP-III fluid. While in a hurry, I took a guess and bought Dextron-III from the store, thinking that the “III” probably means it is equivalent to SP-III. I was wrong. This is very confusing because there are so many trade names. However, the back of the bottle should list all the compatible types.

The leak, however, was easy to identify. It was coming out of a flare fitting at the bottom of the radiator that somehow had come loose. But now I had to deal with that one quart of wrong fluid mixed in. It might not be serious, but just to be safe, I decided to drain as much of the fluid as possible to fill with the correct type.

On the Kia Rio, there is no drain plug on the oil pan. The recommended method is to remove the oil pan. But that was going to be a big pain. The simpler method, which I believe is just as effective, is to insert a plastic tube through the dip stick tube until it hits the bottom of the pan, and use suction to pull the fluid out. Using a hand pump, I got 3 quarts out. The capacity is 5.2 quarts. Even if you drop the oil pan, I don’t think it would have been possible to get more out, since about half of the oil is in the torque converter.

Water Pump Replacement

One would think that replacing a water pump should not require tearing down the engine. But on the Kia Rio, the water pump is buried inside the engine block behind the timing belt making it a major job. A lot of things have to be removed to access the water pump. Additionally, a leaking water pump will soak the timing belt and the rollers. If the timing belt breaks, it would cause irreversible engine damage. So any issue with the water pump must be fixed right away.

Radiator hose and fan removed

First, the radiator has to be drained, and the upper and lower radiator hoses have to be removed. The radiator fan also has to be removed. Even 1-2 inches of extra room makes a tremendous difference, which I found out the hard way.

The windshield washer reservoir and the power steering fluid lines needs to be unmounted from the wall and moved out of the way. This is for making some working room on the left side.

Windshield washer reservoir and power steering lines removed

Both drive belts and the water pump pulley have to be removed. The power steering pump has to be unmounted and moved out of the way. The AC compressor also has to be unmounted from its bracket and moved out of the way.

The passenger side engine mount has to be removed and the engine jacked up. This raises the left side of the engine to give better access to the timing belt housing. Next, the top timing belt cover can be removed.

Engine mount removed

The crankshaft bolt and the harmonic balancer have to be removed. This will allow the two lower timing belt covers to be removed.

With crankshaft bolt removed

Before removing the timing belt, the crankshaft has to be rotated until the camshaft alignment marks are correctly located. The tensioning roller has to be compressed to allow the timing belt to be removed. Next, the timing belt rollers can be unbolted from the water pump housing.

Alignment of the cam sprockets

But before the water pump can be removed, its inlet connector has to be unbolted. Unfortunately, this area is blocked by the AC mounting bracket, requiring it to be removed from the engine block.

Water inlet connector is behind the AC mounting bracket

Once the AC mounting bracket is removed, the inlet connector is easily accessible from below.

Water pump inlet connect from below

Finally, the water pump can be removed from the engine block. Once removed, the mating face has to be scraped with a blade to remove all traces of the old gasket. This is in a tight spot, making cleaning and inspection quite difficult.

Water pump’s mating surface on the engine block

The next step is to install the new water pump. The general advise seems to be to avoid using sealants when mounting the new gasket. However, it is nearly impossible to do this without using some Ultragrey as a glue to hold the gasket while placing the new water pump.

Water pump gasket

It is quite tricky to maneuver the water pump through the tight spaces without scratching the mating surface or tearing the gasket. It takes several trial and error attempts.

New water pump installed

The water pump’s inlet (which is accessible only from the bottom) needs to be connected next, but it also connects to the cabin heater return line. Since this is a rigid line, it needs to be disconnected at its other end to to give it some flexibility. Its mount point is hidden behind the exhaust shield, necessitating its removal as well.

Water pump inlet from below

The exhaust shield is easy to remove, but its bolts were corroded and frozen, requiring some of them to be drilled out.

Exhaust shield removed

The water pump’s inlet requires a gasket. Again, it is tricky to align the bolts without scratching the surface or misaligning the gasket.

Inlet connector assembled

Finally, the new timing belt can be installed. The rollers have to be installed first, which bolt directly onto the water pump. While placing the timing belt, care must be taken to ensure that the cam shaft alignment marks are maintained accurately. Then the tensioning rollers can be torqued to the specified value (35 ft-b).

Timing belt roller

The second roller is for tensioning. It has a spring that pulls on it to add tension to the belt. The roller has to be pushed with a wedge as far towards the spring as possible and the bolt tightened. This will allow the spring to be extended and connected by hand. Then the bolt is loosened to allow the tensioning mechanism to work.

Tensioning roller

The timing belt cover has three pieces. Mine was cracked in several places and significantly deformed. These are hard to find and had to be ordered through the dealer.

Timing belt covers (three pieces)

Transmission Range Sensor

I’ve had repeated problems with starting. After replacing the battery, starter and ignition key switch, the only remaining component in the system is the transmission range sensor. This vehicle has no starter relay – it is built into the starter. Incidentally, I also found that the 10A starter fuse is completely unused in this car. Pulling the fuse does absolutely nothing to the starting system. The range sensor is an electrical switch that sits on top of the transmission where the shift level cable is attached. It rotates with the transmission shaft, sensing whether the transmission is in park, drive, neutral etc.. The neutral safety switch closes only when the transmission is in park or neutral, allowing the car to start only under these conditions.

The range sensor is cheap ($35) and is easy to replace. After removing the air intake duct, the sensor is easily accessible from the top. The shift cable has to be detached from the transmission shaft using a 21mm socket. The sensor itself is only held down by two hex screws.

Location of the range sensor (with the sensor removed)
Range sensor
With new range sensor installed


Replacing the alternator on the Kia Rio is probably one of the most difficult work I have done, which is a strange thing to say because I have done far more complex tasks on this vehicle. Even though it is relatively easy to disconnect the belts and remove all the retaining bolts, there is simply no room to extricate the alternator out of the engine.

At the top, the path is blocked by the AC lines and the power steering lines. At the bottom, the the mounting block obstructs the path.

After checking many sources of information, the only apparent way to get it out was by lifting and moving the engine. This clearly seems like a poor design and unnecessarily complicated.

Therefore, passenger-side engine mount was removed, letting the engine hang from the other mount points. Then a hydraulic jack was placed under the oil pan to lift the engine block. This procedure moved the engine by about an inch, and allowed the alternator to just barely squeeze out of the bottom of the vehicle with no extra room to spare.

Door lock

Door lock problems may appear minor, but fixing them is not easy, especially if the door is stuck in the locked position. Getting in and out of the car from the passenger side is a major pain in the rear.

With the door closed, it is not possible to remove the panel to examine the problem. So, the first task is to try to unlock the door by inserting various long tools, coat hangers, welding rods etc.. through the window crack. To make matters worse anti-tampering devices will make this process very difficult.

Thanks to a youtuber, I was able to zoom in on the problem area and jostle the mechanism to unlock it. The problem was a broken spring, which was trivial to replace once everything was open and accessible.

Inside door panel before removal
After removing panel

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.