Water pump swap tips...

[Anonymous]

Looking at putting on a new water pump.

Here's why...

I flush out the radiator fluid, and then refill and bleed off air, the engine will make a whirring / scraping sound when running after about 1 minute after it is started. Noise seems to come from water pump area. Then it goes away. Could I have dislodged junk that is rubbing on the impeller?

Any ideas? Could it be a dry water pump, but I know it had fluid in there. Or a bad water pump? Although It stays cool and never overheats.

In any case how hard is a water pump change? Any tips?
I've heard horror stories about broken off bolts, etc...

I plan on a new water pump, bolt kit, thermostat and thermostat housing.
Total cost about $80 via NPD.

Steve-O

 

[Anonymous]

Steve-O, changing the water pump is pretty straight forward. I wouldn't hesitate to change it if I were you.

You know, when my pump went bad on my old engine, it made a scraping sound. When I got it out, the impeller blades were all scraped up and it appeared that they were scraping on the outside wall of piston #1. The tolerance in there is pretty tight. When I put the new one in, and torqued it down the new pump was binding against said wall. In frustration, I put a second gasket in, and it worked fine.

I didn't have to use two gaskets when I put the pump on my rebuilt motor, so I'm not sure what was going on. I wouldn't be surprised if the shaft on your pump has loosened up a bit and those blades are scraping.

Also, when you replace your pump, pull your radiator first and the job will be much easier.

Ryan

 

[rbohm]

8) one tip;

when you put sealer on the gasket area, whether you use one or two gaskets, or none, use THIN coats of sealer. i use my finger to apply the sealer, and i like to use permatex #2 for water pump gaskets, though sometimes i will also use black rtv silicon. just remember thin coats of sealer.


oh and torque the bolts as evenly as possible, best to use a torque wrench if you have one that has a low enough torque setting.

 

[Anonymous]

changing a water pump is pretty easy.

last year i got the stang running for the ex's prom, the day before the prom i finshed the rebuild on the ehgine, dropped it in and tuned it up, then that night i took her out for a spin and the bearings in the water pump went bad, i wasn't about to drive around with a water pump that was screaming like a loose belt, so the next morning i went out picked a new one up, painted it and while the paint was drying took off the old pump, which took about five minutes. thenput some silicon on the new gasket and put the new pump on.

that's before i had the electric fan but i would think it's not that hard even with it.

 

[Anonymous]

Also, make sure the bolts you are getting are the same size as stock. I had to cut the AC bracket (I didn't have AC or PS) to get a heater hose from burning against the exhaust, and when I put the bolt back in it went down into the water passage more. So when I started up my car, CRUNCH...SQUEAK... I had bent the propeller fan. While that was probably just stupidity on my part I'll share it anyways just in case you get the water pump in and it feels like it's "hitting something" but it's not hitting the #1 cylinder wall.

 

[Anonymous]

Gang,

All good stuff as usual. Thanks for the info.

Steve-O

 

[Anonymous]

Using two gaskets for the water pump could make good sense. Around here, I learned that, as it comes from the factory, the water pump pulley isn't perfectly aligned with the crank pulley. Using two gaskets takes care of the problem. You should check that, I think.

 

[Anonymous]

I'll get an extra gasket. Anyone have a rough idea of the torque for the 3 water pump bolts?
Steve-O

 

[WhitePony]

Steve,

According to the shop manual 12-15 Ft-lbs. I'm not sure if having two gaskets would change that.

Kris

 

[Anonymous]

Well I changed out the water pump this afternoon.

I had picked up a water pump at pep boys for $29.99 yesterday. It was for a 200 inline six. Since they're almost all the same, I thought I'd give it a whirl.

I pulled out the radiator at the recommendation of people here. A very good idea, I might add. Pulled off the fan easily.

The bolts for the waterpump were dirty but came right out. I went to the corner parts store and got some new ones (same size). Also the heater hose take off was badly coroded, so I replaced it.

The water pump looked horrible on the inside. Lots of rust and gook. I took the chance with it off to clean things out again. Also flushed the radiator real good. The impller was pretty nasty, too. Could easily see how it could start rubbing on the #1 cylinder if it was too long. Mine fit great and test turned real nicely.

Thanks for all the help. Next step...a compression test.
The impeller:

Looking into the intake (lower left opening in image above)

 

[wallaka]

Ooh, nasty. Looks like one of those 4.3 Chevies when they first switched to the dex-cool (orange) antifreeze. Of course, it only took a year or two for those...

 

[addo]

Actually, if the old pump was still sealing, it'd be OK for a mild application. I've seen far worse than that. Remember that fine flaky and silty crud is still hiding in all the stagnant passages - especially in the cylinder head and back of the block. It's why I like to rip through the water jacket of the head with glass beads during a rebuild.

Cheers, Adam.