I've never seen the water pump gaskets (between the pump and the block) begin leaking until now, never even heard of it happening. I replaced the water pump on this 2001 Express van and here I am, a little over a year later, replacing the gaskets. It seems the gasket on the passenger side began leaking and when I pulled the pump off, the gaskets look like they have actually disintegrated. I use the original green antifreeze in it and it'* been driven off and on for the last year with no overheating issues. In fact, it was driven almost 600 miles just last weekend with no problems...then on Wednesday evening, it overheated with this issue.

Has anyone else experienced this sort of problem?

I have seen this many times over on the LS engines. At least it'* a fairly easy fix and I usually use anaerobic sealant on the gaskets as a added insurance policy. Also many folks like to switch to regular green coolant from the dexcool because it tends to be less corrosive on the gaskets.

William, he doesn't have an LS engine. He has the regular Vortec 5.7.

As a precaution, both mating surfaces of the pump and block must be gasket free. Which usually requires a good sanding using an air tool. Then replace with a good brand of gasket material. If it does it again, I would suspect you have a warped pump.

Mike a 01 express van should of came with the LS engine unless it was a V6 I thought.

Switch over to the L.* platform was in 03.
Id do as mike suggested make sure the block is clean of gasket material.

If using a air tool sander BE VERY CAREFUL CLEANING, IT DOESNT TAKE MUCH SANDING TO WIPE AWAY METAL. Running your finger nail over the surface will help find old gasket material left over.

I usually use the standard fiber gasket you buy at the parts store and silicone gasket sealer when installing one. Is there a better sealer available? I have never heard of the "anaerobic sealant" sealant; what is this?

Gasket alone should be sufficient unless the block or the pump is slightly warped or pitted. I usually apply a small dab on the gasket just enough to hold them in place while installing the pump. Regular high temp silicone should be enough. I use engine sealant that G.m. makes. Its a lot tackier and lasts a lot longer than permatex.

Since I thought you had the LS engine I was thinking of the aluminum gaskets with the injected silicone seals. I use anaerobic sealant on these kind of gaskets. When it comes to the paper and fiber gaskets I like to use a light coat of permitex aviation sealant or permitex high tack sealant.

Racer,

It has a 5.7 L Vortec 350. The original engine was having issues on cylinder 3 and I found a 98 chevy pickup with this engine and only 147,000 miles so I bought it and put it in.

Mike,

I'll have to sand it by hand so no risk of damaging the surface...there'* not much room to get a tool in there.

Thanks to everyone for the answers and suggestions.

I use Never Seize on the gasket, and never had a problem....making the mating surfaces perfectly clean(have seen burrs on new pumps) is paramount.....and with that Never Seize, the next guy who gets that job will thank you....and with the crap they are selling out there, it will happen....

And then we have the debate of using gasket removal discs vs a good scraper.....have seen guys gouge surfaces with these discs......I have used those rubberized discs with the "fingers"....less chance of gouging but you don't want any of that material from the disc getting in the engine....