Hi,I'm looking for help on water pump gasket failure.I'm running all GM stuff,block,water pump,pulleys,brackets,balancer,fan,radiator,thermo stat. Ive been blowing gaskets for about 6 yrs. now, and I'm getting pretty tired of it! (AT LEAST 25 IN THE LAST 6 YRS.) I'm on my 3rd different block,3rd different water pump,all pulleys have been changed ,different balancer.Ive studded the block for the pump with double nuts,loc-tite,new bolts,ground off a little to insure they don't bottom out,New lock washers,even went as far as cutting 2 one inch pipes about 2" long and drove them in the block to mount water pump on ,and it still blows the gaskets at about 6500 rpm.I know ,don't run 6500 rpm,this is hard to do if I go to the track.The car has never run hot or anything,it just blows gaskets.
Any help at all would be greatly appreciated.

Just to be sure.......don't over-torque the bolts/nuts.....and have you tried using some RTV or other gasket sealer? Again, these are just thoughts....You've probably already covered these areas.

Sometimes waterpumps and thermostat housings will get a burr on the edge of them, usually from being dropped or banged around.
It will put a dent and raised spot on the edge.

Clean the mating surface real good, I use just a little bit of lacquer thinner.

Lets say the width is eight inches, just guessing here.

Get a flat file, a ten or twelve inch would work good. Lay the file flat on the surface, then with just light pressure move the file back and forth, just a couple inches back and forth, you want to keep from rounding the edges over, light pressure, you will see a shiny spot or two on the edge of the pump, also do the block to.

The file needs to stay flat with the surface, light pressure.

Hope this might help you out.

Rob

Sure its not hitting the front cover or front cover mounting bolt?

Thanks for the response.I'm not sure I know what bolt you are talking about.I don't know if there is a difference or not but I'm working on a small block chevy,are you talking about a big block chevy maybe??

Hi ,thanks for the thoughts.I've thought about the mating surfaces and went as far as putting the pump in a vise and straight edged the surfaces and used the flat file and squired them to one another. The pump showed to be quiet a bit out of shape with the straight edge,when I found that I thought I had found my problem,so I got them back in shape with the file and I've checked the block the best I could with the timing cover in the way and filed the block just a few strokes to see if it showed any bad spots,I didn't see any problems on the block so I put it together again.After a few passes it started squirting water again.I've noticed that when I take it apart it looks like the gasket has disolved, do you know of any type of high perf. gaskets made of something other than paper?

Brent ,Thanks for the thoughts,I used to just throw a water pump on and tighten it up. Then when I started having this problem I thought I might be mashing the gaskets out so I started using a torque wrench on them ,I been putting about 45lbs on them. As far the rtv, if it has liquid in it, I put permatex on it. Thanks,,,,

Have You Tried A Different Water Pump? If Not Try That With A Good Quality Gasket Such As A Fel-pro Or Something Similar.

For instance, when you mount a 'short' pump on a ZZ4 (small block), the pump body hits one of the front cover mounting bolts. It can be "modified" to clear but would not tighten up on the gaskets correctly unless you did the mod.

Hey,thanks for the info on the short pump,I have not had any experience with a short pump other than removing one or two off of a block that I was going to use.All I ever used is a long pump so I don't guess it as hitting the front cover bolt. Thank you for taking the time to make the suggestion.

Hi,Yeh I've tried three different water pumps and they all do the same thing.Do you think that running just pure water is having any effect on the gaskets themselves? I haven't run antifreeze in years.

Hey,thanks alot to all the folks that replied to my post on "waterpump issues" I replaced the radiator and so far after 22 passes it has not blown the gaskets (yet) .
THANKS YOU ALL!!!