Water Pump Question

[Firemanshort]

I am in the process of rebuilding my motor. In the tear down - I have taken apart the water pump (which was working fine as far as I know).

See the photos - it looks to me like something besides water worked its way through the water pump. Has anyone seen this before? I expected the surface on the inside of the water pump to be consistent and smooth.

More importantly. what is my next step? I think this was working fine - so do I jsut put it back together? Do I replace just the pump? (Please do not say timing cover housing, too!!) :confused

[1962siia88]

I would definitely replace the pump. I wouldn't worry about the rest of it. I'd also flush the system real well to make sure the little bits of impeller are all out! Of course I'm a lazy bumm so others may have a different opinion. At least you caught it before the whole pump went! Good luck.

Daniel

I am in the process of rebuilding my motor. In the tear down - I have taken apart the water pump (which was working fine as far as I know).

See the photos - it looks to me like something besides water worked its way through the water pump. Has anyone seen this before? I expected the surface on the inside of the water pump to be consistent and smooth.

More importantly. what is my next step? I think this was working fine - so do I jsut put it back together? Do I replace just the pump? (Please do not say timing cover housing, too!!) :confused

[junkyddog11]

That is not at all unusual. I'm not sure if it a result of some sort of chemical reaction and/or just turbulence but I see it frequently in older aluminum motors, but generally just in the water pump which leads to the turbulence thought.

[cgalpin]

Definitely replace it, but lets see pics of the cover.

------ Follow up post added December 8th, 2010 01:24 PM ------

Duh, you did show the cover. I think you can get away with that just fine.

[Ren Ching]

the water pump is cavitating. the damage to the cover is exacerbating the problem. i would change both if possible and use water wetter to reduce cavitation in the new components.

http://en.wikipedia.org/wiki/Cavitation

bummer...

[cgalpin]

Damn Ren, such a downer...

Dave S. I'm still waiting for the friggin engine I bought or I'd offer you the front cover (and exhaust manifolds) off of the one I have here. But until I know I don't need them I'm holding on to them.

[rijosho]

I'm still waiting for the friggin engine I bought or I'd offer you the front cover (and exhaust manifolds) off of the one I have here.

Did I miss something? For the white truck? New thread w/ details?

[Firemanshort]

Ren Ching - The fireman understands cavitation :) - this may be a relic of when the truck was run empty of water back with the radiator was clogged and had a leak. There were numerous times I had to stop and refill back when I first had the truck. Who knows what PO did, also.

Charles - The D-90 manifolds are a different shape to my STAGE ONE manifolds. The engine bay is slightly different (coil spring vs leaf spring set up). The water pump may or may not be different based on pulley configuration. I am still researching that issue. I could probably make the D-90 parts work in a pinch but I am trying to keep the STAGE ONE correct parts where I can.

What I am really counting on you for it to buy the clutch allignment tool and letting me borrow that.

Oh - did your heads have 14 bolts per side or 10 bolts per side? :confused

[cgalpin]

Alright mr fancy pants STAGE ONE. 10 bolt heads. Gotta get the clutch alignment tool still...

[Firemanshort]

Charles - I sometimes wish I had a more main stream truck - especially when I pay for parts.

I need two head bolts - but the two I need are in the 4 that your truck does not use - see what I mean? RN and AB want to sell them for almost $17 a bolt.

[Ren Ching]

i thought those bolts get left out on later rebuilds, dunno...

[Firemanshort]

Ren - Correct - the bottom four bolts are left out on the later builds of the 3.9 with composite gaskets. My motor and its metal head gasket calls for all 14 bolts to be used. I verified this with the guy at AluminumV8.com.

[huck1974]

Ren Ching - The fireman understands cavitation :) - this may be a relic of when the truck was run empty of water back with the radiator was clogged and had a leak. There were numerous times I had to stop and refill back when I first had the truck. Who knows what PO did, also.

Charles - The D-90 manifolds are a different shape to my STAGE ONE manifolds. The engine bay is slightly different (coil spring vs leaf spring set up). The water pump may or may not be different based on pulley configuration. I am still researching that issue. I could probably make the D-90 parts work in a pinch but I am trying to keep the STAGE ONE correct parts where I can.

What I am really counting on you for it to buy the clutch allignment tool and letting me borrow that.

Oh - did your heads have 14 bolts per side or 10 bolts per side? :confused

Sorry to butt in, Mitsubishi plastic clutch alignment tool for $3 from auto parts store fits perfect.

[cgalpin]

Thanks Shane. That's one of the things I keep forgetting to buy so knowing this will save me a few pennies, thanks! Butt in anytime!

How is it coming Dave? BTW, I bought that Disco you alerted me to. Engine is half disconnected, and should come out Sunday AM :)

[Firemanshort]

Charles - sweet news on the purchase - what condition was the truck in? I am in Maine for the Holidays so no wrenching going on. The replacement water pump is in the mail. I figure I will have it back in the truck near the end of January - not because there is that much to do just I have that little time to mess about in the garage :(

(and the manifold may prove to be the trickier part of the equation)

[Red90]

You should always replace the waer pump in any engine being rebuilt. It is not worth destroying an engine over a low cost ancillary.

[cgalpin]

The truck has something wrong with the transmission, but I bought it because the engine ran well and sounded good. The thing has literally no rust which is quite surprising. I have service records up to 88K (has 135K on it) and appears to have been owned by a fire chief or dept or something as the warranty work seems to have been paid for by the firemans fund.

[huck1974]

The truck has something wrong with the transmission, but I bought it because the engine ran well and sounded good. The thing has literally no rust which is quite surprising. I have service records up to 88K (has 135K on it) and appears to have been owned by a fire chief or dept or something as the warranty work seems to have been paid for by the firemans fund.


Roverguy probably has one cheap

[cgalpin]

Roverguy probably has one cheap
I bought the truck for the engine which is now out. Roverguy will get the rest :)

[huck1974]

I bought the truck for the engine which is now out. Roverguy will get the rest :)

You guys are always way ahead of me. :)