Thermo stat housing

[Vs_ss_gmtank]

Well my thermo housing was leaking on my vs ss so I went and bought a new gasket for it and I thought while I'm taking it apart I will change the thermo stat while I'm at it.

Take the housing off clean it all up put the new gasket, o-ring and new thermo stat in tighten it all up..

Started the car up and bleed it was all fine, Now the next day its leaking again?
Bolts are tight as, dont want to do them to tight and snap the bolts. The gasket should have sild by now.

Are you ment to use a gasket and also the gasket silcon as well? I thought you use just one or the other.

[Vee-ard]

in a perfect world, you should just need the gasket, but I've done it twice now and had it leak both times, use silicon just to be sure.

[delcowizzid]

if it has an oring its most likely not meant to have a gasket

[Smitty]

Well my thermo housing was leaking on my vs ss so I went and bought a new gasket for it and I thought while I'm taking it apart I will change the thermo stat while I'm at it.

Take the housing off clean it all up put the new gasket, o-ring and new thermo stat in tighten it all up..

Started the car up and bleed it was all fine, Now the next day its leaking again?
Bolts are tight as, dont want to do them to tight and snap the bolts. The gasket should have sild by now.

Are you ment to use a gasket and also the gasket silcon as well? I thought you use just one or the other.

you sure its leaking...???
I did this and found it leaking again
'cept it wasnt

It was the heater hose tap thingy behind it that was the culprit....

[Vs_ss_gmtank]

Just replaced the heater tap so I know its not that..

I might just have to do it again and use the silicone lol?

[hako]

The silicone you use with the "O" ring to allow it to seal properly is "silicone grease" - it's not the silicone that solidifies. This grease allows the "O" ring to seat properly. If it still leaks make sure the base of the housing is flat - if not, smooth it with wet and dry.

[rocco555]

did you make sure the mating surfaces were clean, with absolutely no old gasket material left behind?

and, if yes, are you sure you didnt damage either of the surfaces?

it shouldn't leak with a gasket if the bolts are tightened enough... only thing i've ever used is some water proof sealant on the threads of the bolts

[Vs_ss_gmtank]

mmm Well I did clean it up real good... so I dont really know why its still leaking... I might just pull it apart again, clean it up real nice and try using just silicone?

[simmons001]

I always use gasket goo and a gasket. always.

[rocco555]

yeah it has to be CLEAN

scrape off the gasket with a paint scraper (or similar), then use a fine grit sandpaper and some cleaning product to finish it off. should be completely smooth to the touch by the time your done. put a new gasket on, loctite the bolts, and tighten them up very good.

unless your mating surfaces are damaged, you can't go wrong like this. let us know how you go...

[Vs_ss_gmtank]

^^
Hopefully give it a shot this weekend.. So whats the best to clean the surface with? Also should I just use the gasket goo just incase?

[simmons001]

I would say yes. A LIGHT coating both sides of the gasket IMHO

[rocco555]

just use some sandpaper and finish off with any product you have lying around to clean off any excess (whatever works, you won't do damage, its just a piece of metal remember )

using gasket goo wont hurt either, as simmons said, a little either side of the gasket.

and remember some water proof thread sealant on the bolts

do this and you cant go wrong,

and again, let us know the result

[Vs_ss_gmtank]

^^
Cheers mate, got some sand paper and gasket goo at home and just went and bought a thermo stat gasket tonight so Ill change it tomorrow.

I tryed to buy an O ring to but he said they dont have them and he has changed a few thermo stats himself and never used/had a O ring. But when I pulled my housing off there was an rubber O ring in the housing..

[rocco555]

shouldn't be an o-ring in there...

if the o-ring sits between the mating surfaces, it could be the cause of your leak

if its actually inside the housing, i can't imagine what its purpose would be?

if it aint sealing anything, get rid of it.

[Vs_ss_gmtank]

There is actually a grove in the top housing which it sits in there... Dont know why its there for or even why there is a grove for it because it dont do nothing?

[rocco555]

sorry mate, totally for got your talking about an 8

just throw it back in

it won't be the source of your leak tho so dont worry about it



gasket, gasket goo, tight bolts, bleed the air out and she'll be good

if, after doing all that, it leaks a tiny bit from the bolts, wait for it to completely cool down, pull a bolt out one at a time, loctite the threads, and then tighten them up again.

[Vs_ss_gmtank]

Well I took the housing off. Got the old gasket off with a Stanley knife then got some sand paper and cleaned both bottom and top housing..

Put the gasket goo around the bottom housing, put the new gasket on then put some more gasket goo on top. Done the bolts up nice and tight. Let it dry for an hour then I bleed the system and nothing has leaked yet. But prob wont no till I go for a proper drive.

Gee I hope it has working this time, really cant be bothered doing it all AGAIN

[shiftySLE]

if, after doing all that, it leaks a tiny bit from the bolts, wait for it to completely cool down, pull a bolt out one at a time, loctite the threads, and then tighten them up again.

this is one last step that helps heaps, good advice

[Vs_ss_gmtank]

I just went for a drive got back home and its leaking again!! lol

I seriously dunno what to do now! grrrr I done everything that you guys said to do and it still leaks lol DAMIT!

[Vee-ard]

is it the sealing surface around the thermostat or the hose clamp being too loose on the thermostat housing?

[Vs_ss_gmtank]

nar its going out from the sealing surface around the housing... its still finding a way through the gasket goo and just starts to leak again

[simmons001]

never had this problem on any of the thermo housings ive done (253, 308, 304), so have to ask the stupid questions.

No scores in either surface? Using a light coating of goo? correct gasket? goo or loctite on the bolts? correct bolt torque?

I mean they are designed to not leak and the thermostat be easily replaceable, so there is something going on

[Vs_ss_gmtank]

Bolts are real tight, dont want to do to tight and snap them.

Both surface was smoothed off with sand paper to a smooth touch.
Used correct gasket with light coasting of goo..

I really dont know why its leaking still, though its just a tiny bit of coolant is seeping out.

I might buy some different goo tomorrow and give it another shot but just use gasket goo and a new O ring??

its seriously doing my head in.

I might even go one step further and buy a new top housing for god sake!

[rocco555]

mate you really shouldn't be having this much trouble

sounds like your housing may have a hairline crack in it or your surfaces are scored... (very unusual)

buy another new/used housing, get a new o ring, and DO use another gasket

see how u go