Changing the water pump on second-generation V6 Chrysler minivans
Changing the water pump is easy — it took me 45 minutes TOTAL for everything listed here!
I own and drive a 1994 Town and Country, 3.8L V6.
- Loosen the lug nuts on right front wheel, after opening the hood, removing the serpentine belt and draining cooling system.
- Raise and safely support the vehicle (using blocks behind and in front of the rear tires should be done too for safety reasons), DO NOT use the jack alone for support, use blocks or jack stands!
- Remove lug nuts and right front tire.
- Remove splash shield, this means removing about a half dozen screws, all of which go into threaded holes or speed nuts, don't worry about mixing them up, they are all the same.
- Using a screwdriver in one of the pulley holes to jam the pump pulley there-by preventing pump rotation (there is a conveniently located flat spot just for this on the timing cover).
- Remove the (3) 10MM bolts from the fan pulley, the pulley should then drop off in your hand.
- Loosen (carefully) the 5 (again I think they were 10MM, maybe 12 MM) water pump bolts (it may help to spray the bolts with PB blaster or other penetrating oil), then pull firmly on the pump shaft, and the pump will come out of the housing and land in your hand. Also make sure the old O-ring didn’t stick to the pump mating surface, if it did, just peel it off with your fingers.
- Install the O-ring (new one should come with the pump) in the new pump groove and place the pump in the housing. Start each bolt by hand and tighten until the pump is in the housing. Make sure the o-ring has seated in the groove on the water pump.
- Torque the bolts until snug but not overly tight. I think my book said around 100 INCH lbs of torque.
- Install the pump pulley and again using the screwdriver to lock the pulley against rotating, tighten the pulley bolts firmly.
- Install the splash shield and its bolts.
- Install the right front tire and snug the lug nuts up to get the wheel centered on the hub.
- Remove the supports and lower the vehicle.
- Torque the lug nuts to 95 Foot Pounds torque.
- Install the serpentine belt (use a new one! Water pumps like to take belts with them!)
- This step is MANDATORY! The bleed valve in most thermostats isn't big enough to bleed the gargantuan amount of air from the cooling system at any noticeable rate of speed. Doing this GREATLY reduces the amount of time to bleed the system of ALL the air trapped inside.
Disconnect and remove the engine coolant temperature sensor, it is located DIRECTLY under the coil pack and is threaded into the manifold, next to the thermostat (you have to remove the coil pack for this, I just removed the coil pack and rested it to the side, still connected to all its wiring).
- Fill the cooling system until coolant flows from the sending unit hole, re-install the sending unit, using thread seal tape to prevent leaks (don't forget to plug it back in) and coil pack.
- Continue to fill the cooling system through the radiator until no more air comes up. Squeezing the upper radiator hose helps to bleed the system [editor’s note: be careful! If your hose is bad, it can explode and cover you in boiling hot antifreeze. Wear eye protection at the least].
- When you are sure that most of the air is out of the system, turn the heater(s) the FULL HOT and turn the fan(s) on low speed. Turning the heaters to full hot opens the heater valves allowing maximum coolant flow through the core(s). (Some vehicles (like mine) are equipped with front and rear Heat and A/C, that’s why the (s) is thrown in.)
- Leave the radiator cap off, start the engine and let run until thoroughly warm, I mean WARM, as in, THE RADIATOR FAN CYCLES ON AND OFF and you can see the coolant flow passed the cap opening (meaning the thermostat is open)! Continue to add coolant as necessary to keep the system full. Keep an eye on the temperature gauge during this time, if at any time is seems to be getting warmer than it should, IMMEDIATELY shut the engine down and track down why the engine is getting too warm! The gauge will normally run a little higher at idle, due to the fact that the fan will not come on until the gauge is just shy 3/4 way up the scale. At least, that’s the way my digital gauges read before my fan comes on.
- Once the fan cycles (this take about twenty to thirty minutes at idle), and all the air has been bled from the cooling system, replace the radiator cap, refill the reservoir with water/coolant mix.
- Pick up your mess and pat yourself on the back for a job well done!
Like I said earlier, this process takes under an hour, and is easy to do, just follow the steps to the letter and you will be fine. If you break a bolt off in the housing, drill it, use an easy-out to remove the remains, re-tap if necessary, and put in a new bolt.
I got lucky and didn't break any bolts. I had a couple that wouldn't budge, but a couple light taps with a ball peen hammer in the end of the ratchet got 'em loose.