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At my whits end with this water leak.

Hey guys,

So this SHOULD be a simple one? But it hasn’t been and it’s driving me crazy. Allow me to explain.

several months ago my water pump developed a leak from one of thre rear gaskets, this allowed a small amount of water to trickle down and get flung everywhere by the Balancer and main belt. It began to squeal like a freaking cat was trapped under the hood. Thats obviously unacceptable. As an added quirk once the engine runs to temp the squealing basically totally stops.

so I replaced the water pump since it appeared to still be the original unit, and got all new silicone hoses to replace what I am certain was the original hoses for the car. (My 99 FRC has about 103k miles) Initially this seemed to do the trick, I degreased the motor with some simple green and expected all was good. A few days later the main radiator hose where it connects to the water pump started a slow trickle leak from the bottom. I replaced the old oem clamps with the type that has a tightening screw, cleaned up the front of the motor again and assumed it was fixed. It was... for a couple weeks then it started again. I moved the clamps a bit, tightened them really tight and cleaned it all up again. The residual dexcool takes a while to burn off at this point even degreased it squeaks for a few days after. I have to physically confirm the leak is stopped and watch it for those days before it’ll stop squealing.

well I had about a month this last time, it was behaving and I thought I finally got it under control.

i have two clamps on that end of the hose, both extremely tight, on a brand new water pump, with a brand new silicone hose, yet the dexcool somehow keeps managing to seep out from the end of the hose and trickle down the front of the water pump onto my harmonic Balancer.

im tired of my vette sounding like I’m attempting to smuggle a family of cats on top of my motor.

if anybody else has dealt with this, or can think of a solution that I’ve not attempted please... I’m at your mercy lol.

I always apply a smear of permatex ultra black on the inside of all hoses.
Dont overtighten!! All that does is distorts and possibly damage the hose or the fittings.

If it keeps leaking at the " brand new silicone hose " I would replace it with the standard black rubber hose. I've never used a silicone hose but if that's where it keeps leaking.....

Quote:

Originally Posted by BigGun (Post 1598458148)

If it keeps leaking at the " brand new silicone hose " I would replace it with the standard black rubber hose. I've never used a silicone hose but if that's where it keeps leaking.....

no way, not with how much these things cost. I’d rather suffer till I find a solution than throw that money down the drain.

Quote:

Originally Posted by pbergmann (Post 1598456536)

I always apply a smear of permatex ultra black on the inside of all hoses.
Dont overtighten!! All that does is distorts and possibly damage the hose or the fittings.

how difficult do you find it to remove hoses with permatex on the inside of the hose?

intriguing idea. Very open to it.

Could be a small defect in the barb that the hose goes on, I think that instead of applying Permatex to the inside of the hose, you should apply it to the hose barb and let it cure for a few hours before installing the hose back on. Hope this helps.

I managed a fleet of Ford and Chevrolet trucks at my former job for 30 years. I converted most of the vehicles to silicone hoses. If we had trouble with a leak at a hose end we used Indian Head gasket shellac and almost every time would solve the problem. It will still come off without any problems. It is cheap and worth a try for you. Good luck

Quote:

Originally Posted by Arvalo (Post 1598456336)

Before adding any sealant to the hose connections, need to make sure what the root cause of your leak is first;Run down to you local auto parts store that has tool rental and get a coolant system pressure tester,

Do the following with the cars cooling system cool to ambient temp.

Inspect the cooling surge tank cap for the proper pressure setting on the cap, remove cap connect pressure tester to surge tank and pressurize the cooling system to the pressure listed on the cap.
Go have a beverage and come back to the car and inspect for leaks.
If the hose is leaking, then you may have a defective hose…If you have NO leaks at the hose, turn your attention the surge tank cap.
Connect pressure tester to surge tank cap, pressurize the cap to see of the pressure relief function is working on the cap. If the pressure relief is not working, (possible overpressure of the cooling system causing leaks) replace surge tank cap.

Cheers,

Goose

Actually like other said... make sure there are no rough edges etc...
The ultra black comes off relatively easy. It does not absorb into either the hose or the outlet. rubs off easyly as it is silicone adhesive.

Thanks guys for the advice. On the topic of pressurization Come to think of it, 6 months ago I replaced my surge tank due to the standard tiny crack and leak at the stem of a hose connection. the original cap was 15 PSI, the new one was 18 psi if I recall. Could that have anything to do with it?

18 psi is the newest cap for the C5. I purchased a new one and that is what the replacement cap was. Silicone hoses are sometimes very hard to seal and as others have said make sure that the neck surface is smooth and clean the inside are of the hose. In a last resort use a sealant. I mentioned Indian head gasket shellac and it really does work and can be cleaned off of the neck easily as well it will not absorb into the silicone hose. One other thing to check is the roundness of the neck. I purchased a new water pump for my 2001 and it arrived in the original box with the inlet and outlet necks beat all to heck. I had to straighten them before installing or I would have had problems with leaks. Good luck with your repair

I would have a CO test on cooling system. A seaping head gasket can keep you constantly fixing small leaks. If CO is negative try adding sealer to hoses.

can you see it leaking from the hose or you guessing its leaking from it?

before i was to replace a new hose i would take it off and see if the the pump outlet is smooth and not corroded like mention above if it is smooth i would see if if the leak was the gaskets on the engine block or someplace else

Quote:

Originally Posted by Stroker87 (Post 1598469316)

basically I can put my finger at the bottom of the hose and get dexcool on it, then dry it off and out my finger there a minute later and it’s begun to seep out again. It appears to leak out from the bottom of the hose, so it’s impossible to actually see, but the trail of water down the front of the water pump from the hose, and the water always being heavily concentrated at the hose has me convinced it’s that.

can you get a mechanics mirror in there with some good lighting and see?

the reason im asking it usually dont take much clamping force to get the hoses sealed, you replaced the pump to the neck that hose is on should been smooth unless some casting flash or something like that

i would pull the hose off and check the hose maybe it got damaged? if the hose checks out its possible the water pump is leaking from t he back plate even though it new thats where the mirror will come in handy

I’ve had the hose off a handful of times at this point and can’t say that recall there being an issues on the neck. The hose itself I’ll have to check out this weekend.

as for the rear leak, I don’t think that’s it, mybold pump was infact leaking from the back plate, and it showed no signs of a leak other than the water on my belts ect.

tgis leak produces clear water marks down the front of the pump as the water cooks onto it with a heater motor.

Im for sure going to try the gasket maker On the inside of the hose idea if the neck is fine on my inspection this weekend.

Quote:

Originally Posted by Arvalo (Post 1598474839)

Was this ever resolved? Im considering swapping to silicone hoses.

Id be interested in this as well.

He applied that silicone and still had a leak. Hes still trying to get the hose but its stuck on.:lol::seeya

Old thread drudged up but here goes. Aside from leaks and hard to seal, research water loss through silicone hoses.