jungy

Just wondering if any one else has experienced this. I did heads and cam over the winter and used new gaskets for everything. I've put almost 1000 miles on the car now and two days ago I drove the car to work, came home and parked it in the garage and didn't go back in the garage for 24 hours. When I came back there was a nice trail of orange under the car starting at the drivers side.

When checking for the exact source of the leak I checked behind the pulley and around the flanges but everything had dried up. I snugged down all 6 bolts again, they weren't loose, and drove it to work yesterday.

Upon coming home I park in the garage and within 10 minutes I've got a small puddle under the car of coolant and this time I can see just a small leak running out behind the top bolt head on the drivers side of the water pump. This only seems to leak when the coolant system is under pressure. Do I just pull the water pump and replace the gaskets again or are those threads going into a water jacket and just need thread sealant?

Bill Curlee

I would look in the service manual and see if the water pump replacement procedure requires thread sealant.

As you probably already know,, the new style GM gaskets are rubber over aluminum and fairly bullet proof!

If the service manual doesn't specify thread sealer, its most likely a bling hole and you have a gasket issue or something more serious.

On a different note, IF, it is a blind hole and you failed to CLEAN AND DRY THE HOLE before you reinstalled everything, you could have forced the fastener into a blind hole with liquid or debris in it and fractured the block behind the bolt.

El original

I would suggest your water pump bearings are piling up. Think about replacing water pump. (if I read your post right)

jungy

The water pump bearings are still good. There is no moisture behind the pulley at all.

The surge tank isn't leaking at all. the only leak is from the top bolt for the water pump on the drivers side.

I'm going to pick up some new gaskets and try this over again. hopefully when i pull it i find the gaskets I installed have a small imperfection that is causing this.

Evil-Twin

All bolts in an LSX engine require anti seize, and torqued with a torque wrench to the proper spec.

jungy

When I reinstalled the water pump during the cam install I put the bolts in dry but I used a snap on torque wrench and torqued them to spec

73Corvette

Evil-Twin

dry bolt torque and lubricated torque are different.. the torque is the same but with a lubricant, the stretch of the primary pitch diameter is increased.

jungy

Yeah I'm familiar with torque and it's effects on bolt stretch with and without a lubricant and also how it varies with different lubricants.

I think I found my issue after pulling the water pump. The drivers side gasket had two bolt holes that were elongated and distorted the gasket. This in turn spaced the water pump out not allowing a full compression of the rubber sealing ring.

I am just wrapping up the reinstall and will report back with the results.

Evil-Twin

BTW.. original OEM water pump gaskets where not a composite... they were a single level cardboard, gasket, and they were tested to failure with 200,000 mile test engines. This newer composite is a better sealing gasket, provided it was not compromised in the install.

Bill Curlee

Thanks for the picture of the gasket. Makes sense.

ET

I had a 98 that had a bad pump. It took FOUR hours to change the pump. Two hours to remove and reinstall and TWO hours to get the old tar gasket off the block! I hate those damn old style gaskets!


Bill

Evil-Twin

I replaced one water pump in my 99 C5 at 60,000 miles. It had the blue paper gasket. It took me an hour to do the job start to finish, and clean up. Easy Peasy.... A razor blade inspection scraper does the job on the gasket. This is a job that almost anyone can do...its a great confidence builder for those who want to attempt to work on their car. There is plenty of room , no knuckle buster issues, easy torque bolts. Dump the coolant, pull the belts and the air bridge, and its right there in your face.. no need for a lift, all done easily from the top.

Evil-Twin

Bill, I am not going to re write my above post.. I did not mean by any stretch to inply that you don't know what you are doing.. far be it from me to step on the toes of a man I respect so much.

After posting it, I re read it and someone might inply that I was being disrespectful.. which was not the case.. If you want me to remove it, PM me and its gone.. I was just trying to use that repair to motivate people who want to get involved with their car.. this is an easy fix and with not hidden surprises.. I grew up on old school gaskets. After pulling the pump, half stayed on the pump and half stayed on the block.. my razor blade gasket scraper took no more than 5 minutes to make it ready for the New gasket and new pump.

My apologies if I offended.

Bill aka ET

Bill Curlee

Bill No HARM No Foul. Blue Paper Gasket??????? Hmmmmmm,, Mine had a BLACK PAPER Gasket and it had a TAR Sealer substance like sticky shellac.

It was VERY difficult to remove off the block surface and the tight spaces didn't help. I did mine in a remote location, (parking lot) and only had a straight edge box cutter blade.

I had one of the very early 98 C5s with the early style pump. Don't know if that made a difference on which gasket that was used.

BC

Ducati Guy

ah yes...permatex. Nasty stuff when it comes time to remove it.

BADBIRDCAGE

AND a cheap inhaled high when working in a non ventilated shop. Miserable headache followed immediately.

Valve covers needed a side smack with a rubber mallet to break the Indian Head valve cover gasket bond.