Water pump woes
elwood blues
Always Off-Roading Jeeper
- Posts
- 6,023
- Media
- 71
- Solutions
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- Thanks
- 48
- Location
- Export, PA
- Vehicle(s)
- 1978 CJ7 4.2L Comp Cam & valve train, MC2100 carb, MSD ignition, Dana 30 front, T18 trans, Dana 20 txfr, AMC 20 rear.
I'm just here to vent because I just had to ordered a second water pump 
A little background info, I've had my CJ for 15 years now. At some point during that time, I remember changing the water pump, there's been a lot of life happen in that amount of time, so I remember having some issues, but I remember getting it right and it hasn't been an issue since. About a month ago I noticed water coming from the weep hole and a distinct noise coming from the front end of the engine that sounded like a failing waterpump bearing.
So, I got online and ordered another from a very reputable online retailer. Start the teardown, spill coolant/water mix all over the garage floor, just for good measure
, while I'm at it, I got new belts, because they're probably 10 or more years old. I had to wait on those, and holy 
are they expensive now BTW, for Gates green strip belts it was $24 and $27 a piece at O'Reilly, holy !
I get the old water pump off and get the new one out of the box, and I notice the impellers are different.
Old one looks like this
The new one looks like this
I texted a friend, a guy who I trust his auto knowledge, he says it looks right, it might just flow more water. Okay, let's get it back together than. I get everything bolted back up, tighten up all the hose clamps a second time because there were a couple of drips, I fired it up and back it out of the garage. It starts getting warm, fast, the temp gauge is steadily headed towards the H and I'm getting a little concerned. Carefully reach down behind the PS pump and squeeze the lower radiator house, it feels empty, jump inside, pull a couple of cables and crank up the fan, no heat either... shut her down and coolant comes boiling out of the overflow, great more coolant on the ground... I get the antifreeze gallon jug out of the recycling and get the overflow hose in it before I loose too much coolant.
After I get everything cleaned up again, and the CJ pushed back in the garage, I do a little Google digging. The water pump I put on (the 2nd picture) is the reverse rotation of the pump I took off. The one I installed is for a later year AMC 258 i6 / 4.2l with a serpentine belt, NOT my 78 with V-belts.
I just ordered the one from the first pic, I guess tonight's project is going to be taking the water pump off again.
Anyway, I just wanted to share in case anyone else is trying to find this info, and to share in my frustration
A little background info, I've had my CJ for 15 years now. At some point during that time, I remember changing the water pump, there's been a lot of life happen in that amount of time, so I remember having some issues, but I remember getting it right and it hasn't been an issue since. About a month ago I noticed water coming from the weep hole and a distinct noise coming from the front end of the engine that sounded like a failing waterpump bearing.
So, I got online and ordered another from a very reputable online retailer. Start the teardown, spill coolant/water mix all over the garage floor, just for good measure
, while I'm at it, I got new belts, because they're probably 10 or more years old. I had to wait on those, and holy are they expensive now BTW, for Gates green strip belts it was $24 and $27 a piece at O'Reilly, holy !I get the old water pump off and get the new one out of the box, and I notice the impellers are different.
Old one looks like this
The new one looks like this
I texted a friend, a guy who I trust his auto knowledge, he says it looks right, it might just flow more water. Okay, let's get it back together than. I get everything bolted back up, tighten up all the hose clamps a second time because there were a couple of drips, I fired it up and back it out of the garage. It starts getting warm, fast, the temp gauge is steadily headed towards the H and I'm getting a little concerned. Carefully reach down behind the PS pump and squeeze the lower radiator house, it feels empty, jump inside, pull a couple of cables and crank up the fan, no heat either... shut her down and coolant comes boiling out of the overflow, great more coolant on the ground
... I get the antifreeze gallon jug out of the recycling and get the overflow hose in it before I loose too much coolant.After I get everything cleaned up again, and the CJ pushed back in the garage, I do a little Google digging. The water pump I put on (the 2nd picture) is the reverse rotation of the pump I took off. The one I installed is for a later year AMC 258 i6 / 4.2l with a serpentine belt, NOT my 78 with V-belts.
I just ordered the one from the first pic, I guess tonight's project is going to be taking the water pump off again.
Anyway, I just wanted to share in case anyone else is trying to find this info, and to share in my frustration
