How to change the water pump on a 1999 Dodge Ram 5.9L

How to change the water pump on a 1999 Dodge Ram 5.9L

The RAM pickup has a huge fan shroud. Once it is out of the way, there is plenty of room to work on the water pump. However getting the fan shroud out is more complicated than just removing the four bolts.

First remove the upper radiator hose at the radiator. You can leave the other end attached to the engine. You will need some special hose clamp pliers to get it out anyway.

Remove the washer bottle by running a long screwdriver down between the bottle and the shroud. There are two tabs that lock into holes in the shroud. Once those are depressed, the bottle will slide straight up. Leave the hose and wire connected to the bottom and set it aside in the engine bay.

Do the same with the over flow bottle. Or you can just remove the hose and leave it attached to the shroud. Remove the four bolts but don’t lift out the shroud just yet.

Next you will have to unbolt the fan clutch. It is held by a single 36MM nut. It is a standard rotation, so you turn it counter clockwise to loosen it. It will likely be too tight to remove even with the special wrench available at the parts store loan a tool plan.

In order to properly hold the water pump pulley from turning you will need to obtain or fabricate a tool that fits in the holes of the pulley. They are 3 inches apart and a 5/16 bolt fits well. I made a tool using a piece of scrap metal and drilled two hole and put two bolts in it to hold the pulley. I was able to hold the pulley still but the thin specialty wrench spread apart before the nut turned. A large adjustable wrench would likely work, but my largest adjustable wrench was too small to fit the nut. On the advice of the parts store counter rep, I used an air chisel. Mine came with a tool that had a notch that caught the edge of the nut well. Using that tool, I was able to get the nut to turn. I made quite a mess of one flat of the nut however.

The fan and shroud are lifted out as a unit. Note that the shop manual warns against laying the fan flat while it is off. They say the fluid can drain into the bearing area causing damage. After cleaning up the damaged flat with a file I carefully propped up the fan in its normal position while it was off.

I then removed the serpentine belt. I used a socket on the tensioner and pulled it to the side releasing he belt. There was a sticker showing the belt routing on this truck so I did not have to worry about making a drawing of the routing before I removed the belt.

With the fan and shroud out of the way, the bolts are easy to get to. Note that there are four long ones. Pay attention to which holes these come out of. In order to avoid a mess, you can drain the radiator before removing the bottom hose. One of the lower bolts goes into the water jacket as well and will drain more fluid.

Once all the bolts are out, you will have to deal with the annoying hose at the top of the water pump. I was able to use vise grips to move the clamp up enough to get it loose. It took a lot of pulling and twisting to get the hose to break free from the nipple. However one it was loose, the pump was free. Replacing this hose requires removing the AC and alternator bracket. So be careful with it.

I used a scraper and wire brush to remove all the old gasket material from the block. I then assembled the new water pump. I obtained a new outlet pipe rather than trying to reuse the old one. I let it out however until the pump was bolted in place. I screwed in the new water nipple using a large flat screwdriver. The nipple came pre coated in thread sealant. Next, I used Permatex #2 to glue the gasket to the pump. I knew that I would have to do a lot of wiggling to get the nipple back into the small hose and I did not want the gasket falling off.

I then slipped the nipple into the hose and started a couple of bolts. Then, I made sure I could get the hose on properly and the clamp into place. I then installed the rest of the bolts and torqued them evenly. I pressed in the new outlet pipe and secured it with its mounting bolt. Next, I installed the lower radiator hose. I then reinstalled the belt.

I held the fan inside the shroud and slipped them into the truck together. Working through the front of the shroud, I started the nut onto the water pump. I spun it a few turns and then installed the shroud. I used the fan clutch wrench from the parts store loan a tool program to tighten the clutch nut. I then reattached the fan shroud and the two water bottles.

I reconnected the upper radiator hose and then refilled the system with coolant. After checking for leaks, I started the engine and continued filling the system as the engine warmed up. The belt had been soaked in coolant from the leaking pump so it slipped some at first. As it dried out however it seemed to work fine.