While my "quick connect" gently weeps...

[billschroeder5842]

I'm getting intermittent seeping of coolant around the "quick connect" fitting hoses on thermostat assembly on my 91. I'm pretty OCD about my Daily Driver car (aren't most of us???) as I do a under hood inspection at least every other day so I just noticed this.

I've check the assembly and I get it "weeping" from the connections with a slight trickle down to the thermostat housing. It is not big (a single drop on the floor per night) but I have my eye on it.

I have the factory thermostat in the car, a new radiator and a Haibeck chip so my fans come on at 205. The engine runs well and cools completely withing spec.

I noticed that the housing and fittings seems to have the metal with a weird "scaling" effect as if it were pot metal. I'm not sure that means anything.

So... anything to worry about immediately? Is there a "usual" fix of this as in a gasket gone wrong? Is this something that will just get progressively worse? Oh, it only seems to weep after the engine is shut off and not circulating.

Also, how the hell do you "undo" the quick fitting? The FSM is a bit vague on the procedure?

I'm not looking to "force" a fix as I can live (but yes it will bother me) with a couple of drops, but I'd like to know what to do if it ever comes to it.

[Dynomite]

You talking about the Heater Hose connection?

Wiggle it a bit and often the leaking will stop.

Heater Hose Connection on Thermostat Housing

See Item #2 Replacing the Heater Core and Heater Hose Connection




See Item #8 The 180 deg versus the 160 deg thermostat or no thermostat

[billschroeder5842]

Originally Posted by Dynomite

Wiggle it a bit and often the leaking will stop.

Now THAT is a repair I can get fully behind.

Thanks for the fitting piece. Jerry's has come through in the past and looksto again.

I have about 75 miles to put on her this weekend, so I'll keep an eye on it.

Thanks!

[RussMcB]

Not sure how easy this would be for you, but...

I have a Stant Cooling System Pressure Tester. It lets you pump up pressure in your system to see if it holds pressure, and helps find leaks.

The process I suggest is, use the tool to see what pressure your radiator cap opens (there's an adapter to test cap pressure). I'm not sure what a Corvette cap usually opens at, but let's say it opens at 20 lb. Then, test your cooling system at a couple of pounds higher (22 lb). If it holds pressure, all is good.

If it doesn't hold pressure, find and fix the leak.

A temporary solution would be to buy a radiator cap with a slightly lower pressure rating. For instance, if the pressure holds at 14 lb (leak starts at 15 lb), buy a 12-13 lb cap. The only downside is the car will overheat at a lower temp (since water boils at a higher temp when the pressure is higher).

I bought my Stant tester 20-30 years ago and it has been used and helpful a lot.

[billschroeder5842]

Well, apparently I need to wiggle a bit more vigorously.

I drove about 50 miles today (GAWD, HOW I LOVE THIS CAR) and checked the fittings. When it cools, I still have the "dropplets" in the fittings.

I have another 50 miles tomorrow, so I'll wiggle a bit more tonight and see what happens.

[Dynomite]

Corrosion gets going inside and the fittings do not make a seal. I had one fitting that was pitted. The only cure then is to drain coolant and take fitting apart, clean it or get new fitting and then back together. No hurry on that with just a drop or two.

Rotating the fitting back and forth might also work making a better seal.
The one that leaked for me was the fitting sending hot coolant to heater which is the threaded fitting Jerry has.


Sent from my iPhone using ZR-1 Net Registry

[billschroeder5842]

Originally Posted by RussMcB

A temporary solution would be to buy a radiator cap with a slightly lower pressure rating. For instance, if the pressure holds at 14 lb (leak starts at 15 lb), buy a 12-13 lb cap. The only downside is the car will overheat at a lower temp (since water boils at a higher temp when the pressure is higher).

Interesting... Never thought about this one.

I have an AC R36 cap rated at 15lbs--- probably the stock cap.

So if I got lower pressure cap as you suggest, what is the down side? Extra fluid in the overfill tank? Less presure means the droplets will disappear?

I have a new radiator and a Haibeck chip so the fans come on at 205. I DO live in Texas so, it will be 105 in August....

Any thoughts of going to a lower pressure cap?

[billschroeder5842]

MY OCD TRIUMPHS YET AGAIN!

I've been keeping my eye on this situation for a couple of week with probably 600 miles and dozens of on/off cycles.

The droplets are still there and I get the nightly single drop on the bottom of the thermostat housing. Seriously, it never (never) drips on the garage flow; it just collects on housing and will often "evaporate" off leaving a thickish residue. A 2 second wipe with a rag and I'm done. Honestly, with all the other stuff in the world this is something I should spend zero intellectual time on.....

HOWEVER...

It just bugs me like no other. I'm just waiting (so I think) on the hose blasting off like a bottle rocket during a hard acceleration and spraying fluid all over the engine. A therapist would have a nice reoccurring income stream if they could ever get me to sit long enough on the couch.

So, I ordered the "Heater nipple" from Jerrys and will plan on doing a repair in the future.

Has anyone done this repair before and can you share any tips? The area is super tight and the nipple is waaaaaaay down there.

Thanks!

[RussMcB]

Originally Posted by billschroeder5842

Interesting... Never thought about this one.
<snip>
So if I got lower pressure cap as you suggest, what is the down side?

"The only downside is the car will overheat at a lower temp (since water boils at a higher temp when the pressure is higher)."

I'm not really suggesting it. Just presenting it as an option. Since you live in a hot climate, you probably shouldn't run a lower cap pressure (unless it's temporary and you're worried about the leak and you're not worried about overheating).

Originally Posted by billschroeder5842

MY OCD TRIUMPHS YET AGAIN!
<snip>
It just bugs me like no other. I'm just waiting (so I think) on the hose blasting off like a bottle rocket during a hard acceleration and spraying fluid all over the engine.

If you're really worried, buy or rent the pressure tester and it can show you if a hose will blow off.

It really is a great tool. I'm probably guilty of going on and on about it, but it will tell you what you want to know.

[garyhugo]

Bill I'm not trying to jump start your OCD but I feel I should share my experience with the quick disconnect on the thermostat housing assembly.I too saw some weeping from the quick disconnect. My Z had about 160,000 miles at the time.I bought a new thermostat housing assembly from Jim VanDorn and drove out to Aaron Scott at SGC to have him do the install. Aaron reached down and tried to disconnect the the fitting and it broke off in his hand sending water all over the floor.He looked at me and said I can't believe you made it here.Just my experience.