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.
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 need to be unmounted from the wall and moved out of the way. This is for making some working room on the left side.
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.
The crankshaft bolt and the harmonic balancer have to be removed. This will allow the two lower timing belt covers to be 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.
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.
Once the AC mounting bracket is removed, the inlet connector is easily accessible 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.
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.
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.
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.
The exhaust shield is easy to remove, but its bolts were corroded and frozen, requiring some of them to be drilled out.
The water pump’s inlet requires a gasket. Again, it is tricky to align the bolts without scratching the surface or misaligning the gasket.
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).
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.
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.