Coolant Leak

[GK]

Hi all,

Looking at some earlier pics of Casper's car, I noticed what appears to be the AU coolant drip / stain. It's in this first pic, the red stain on the flat shiny alloy of the aircon compressor (It is the aircon compressor right?)



The circle (red) is the stain, the green circle is the thermo housing and hose and the yellow circle is ? I'm not sure what this house and metal housing is called, but I suspect that this is where the coolant leaks from.

My S2 SR doesn't leak here at all, but my S1 Futura sure does. On my car the stain is green of course, as I use green coolant.

What have others found? How do you fix it? What's the cost of fixing it?

Cheers,

GK

P.S Hope Casper doesn't mind me using the pic of his car?

[Mechan1k]

Probably the thermostat housing seal is leaking .... or it could be coming from the hose that goes back to the header tank ... the first thing to do is replace the seal ... but seeing as the thermostat is cheap .... may as well get a new thermostat and seal ... not sure if there is a seperate gasket as well.

Especially seeing as it is getting into warmer weather too.

There was a thread with prices for parts for replacing a thermostat and seal .... all up it's be about $30 in parts from memory. Maybe not even that.

[GK]

Have had that thermostac seal replaced, still leaking.

I don't actually think that was what was leaking. It's the hose underneath.

Any ideas people?

GK

[EvilChief]

common problem for falcons to leak there. its either the seal between head and thermostat housing (thermostat housing sometimes warps due to heat and leaks anyway), or it leaks from the big or small hose on the thermostat housing due to corrosion.

[Autocade]

GK
I have found that if the hose clip is positioned too far away from the flange of the pipe housing that under pressure it can push past the gap and cause small leaks
Try loosening the hose clip (when cold)& slide it along the hose
Get it as close to the flange (will look like a bump under the hose)as possible then re-tighten
Be careful not to put it on top of the flange just right next to it
Cheers
Autocade

[skap]

Its the by-pass pipe o'ring
Take the thermostat out, replace the seal, and also replace the thermostat by-pass pipe o'ring. When you take the old one out you will see its all squared.
There are 2 10mm bolts holding the by-pass pipe on the thermostat housing one is underneath the inlet manifold & one is on the thermostat housing.

Anthony

[Racecraft]

Originally Posted by skap

Its the by-pass pipe o'ring
Take the thermostat out, replace the seal, and also replace the thermostat by-pass pipe o'ring. When you take the old one out you will see its all squared.
There are 2 10mm bolts holding the by-pass pipe on the thermostat housing one is underneath the inlet manifold & one is on the thermostat housing.

Anthony

Yep it is the o-ring on the steel pipe that goes from the lower thermostat housing around the engine and to the back of the water puump.. and feeds the heater tap iirc

[GK]

Cheers all,

GK

[wesomc]

Have seen some bypass outlets on the upper housing leak through the sealant (between the alloy and the outlet).
If you can't get the upper to lower housing to seal, try some ultra blue on the new thermostat seal then refit the upper housing

[vince]

Hi,

I have a leaking thermostat housing. I have replaced the thermostat and o-ring, but it is still leaking. Does anyone know of a sealant to use on the o-ring?

Thanks

[Ford Falcon XR6]

Massive thread mine !!!
But I had the same issue with my Au i6 turned our to be the upper half of the thermostat housing was warped due to being over tightened replaced it then it never leaked a drop

[mik]

I usually wack a bit of gasget silastic in the thermostat housing regardless of the o ring, I use whatever silastic gasket stuff I have laying about , but I prefer the red orange stuff , I think its called copper silastic if I can get my hands on it.

[GasoLane]

Originally Posted by mik

I usually wack a bit of gasget silastic in the thermostat housing regardless of the o ring, I use whatever silastic gasket stuff I have laying about , but I prefer the red orange stuff , I think its called copper silastic if I can get my hands on it.

Sounds like the stuff I used to use, comes in a tin with a brush, called Cat Red from a Caterpillar dealer?

[mik]

I cant remember the exact name(getting bad in my old age), it comes in a copper colored tube, it seems not bad stuff (sticks like poo to a blanket) .

[sikford]

Recently replaced all the hoses on the au as well as the water pump and did the thermostat pulleys tensioner belt etc etc...

Did all these things and after I was done now I have a leak from the bottom pipe on the thermostat housing which is quite annoying. Is it the same as the back of the water pump pipe with just an o-ring? When I replace the o-ring do I need to seal it with anything else?

[Spurious]

The heater hose under the thermostat housing is prone to leaking under pressure. My AU2 often left tell tale marks on the A/C compressor.

I did major head off surgery recently & used high temp silicone on the Heater pipe connection & thermo' housing. & vwhalla...no leaks!

Your water pump rear hose fitting could do with silicone too I'd say. Just don't fill the system up with coolant straight away after applying sealant, give it a chance to dry first.

Also my thermostat housing radiator pipe fitting was a little course to the touch so I attacked it with some wet/dry sand paper. It still weeped a little so a ran a bead of silicone just on the end of the hose & it stopped.... & yes the hose clamp was super tight & I used new hoses too!

[vince]

Thanks everyone,

I ended up just buying a new thermostat housing and seal, wasn't too expensive.
Ford also told me that some do warp and all you can do is buy a new one. So I thought I would just replace it and now the problem is fixed.