Assistance with coolant leak

[ThePistonHead]

Hey guys, got an AUII falcon 6cyl and it's had a coolant leak for a few years and i've been trying to get to the bottom of it.

Did a flush and put new fluid in it and now i can see where it is leaking out of:





There was a drop of coolant where my finger is, which i guess is where it ends up before it evaporates.



Can someone tell me what it is (thermostat??) and how i could go about fixing it.

It's a considerable leak.. Had the coolant on full after the flush and it lost about 1/2 a liter in a few days.

Also has anybody been able to get out the full 16 liters out? Could only get out around 9/10 liters even with the bleeding using heater.

Cheers.

[GK]

Where your finger is, (third pic) is the hose that feeds into the heater.

The leak is caused by a small rubber o-ring that goes over time. It's a cheap fix, but I've not actually done it myself, although it's apparently easy. Others here have done it themselves and will be able to talk you through it I'd say.

The thermostat goes in the water pump housing, which is in the area the largest heater hose screws onto, directly above where you have your leak.

All the best with it.

BTW, I may be wrong, but it appears that the top hose connected to the pump and thermostat is a bit bulgy. It might be time for a newy. It could just be the angle of the picture though.

GK

[4ford]

ThePistonHead...
I've recently done that same job on my S2 6.

The replacement O'ring is available at your Ford dealer, very cheap...

The job..with the engine cool or cold, depressurize the cooling system by removing the radiator cap on the expansion tank.

If I recall, it is a 10mm open-ender + 10mm socket you will be needing.

Be prepared to plug the black pipe as you pull it out, or you will lose a lot of coolant.(no pressure, just gravitational flow!).

You will need to remove two 10mm bolts, one at the leak site, and the other a few centimeters down the black pipe, a pipe mounting bracket.

This mounting bracket will be the one to cause some minor problem during reassembly, it's a realignment problem, just need to get things back in line to get the bolt back in.

Don't forget to remove and clean out any remains of the old seal, and make sure the new one is liberally covered in some coolant when you fit it on the pipe, AND when you fit it in the housing.

That's all there is to it, top up your coolant, clean off all the old leaking coolant marks, and check for leaks, job done!

Note: Don't forget you are tensioning steel bolts into alloy housings, so don't over-tighten, just enough is enough.

Cheers

[cjf]

Looks like your thermostat top housing is corroded where the small breather hose sits, take off the hose and clean up the metal pipe with some fine wet and dry paper and trim hose back 10-12 mm and refit hose with a smear or engine silicone around the hose pipe to seal any pitted areas in the metal. Or just buy a new thermostat housing at supercheap or repco or similar parts store and fit it with a new thermstat while your at it.

[GK]

Originally Posted by 4ford

ThePistonHead...
I've recently done that same job on my S2 6.

The replacement O'ring is available at your Ford dealer, very cheap...

The job..with the engine cool or cold, depressurize the cooling system by removing the radiator cap on the expansion tank.

If I recall, it is a 10mm open-ender + 10mm socket you will be needing.

Be prepared to plug the black pipe as you pull it out, or you will lose a lot of coolant.(no pressure, just gravitational flow!).

You will need to remove two 10mm bolts, one at the leak site, and the other a few centimeters down the black pipe, a pipe mounting bracket.

This mounting bracket will be the one to cause some minor problem during reassembly, it's a realignment problem, just need to get things back in line to get the bolt back in.

Don't forget to remove and clean out any remains of the old seal, and make sure the new one is liberally covered in some coolant when you fit it on the pipe, AND when you fit it in the housing.

That's all there is to it, top up your coolant, clean off all the old leaking coolant marks, and check for leaks, job done!

Note: Don't forget you are tensioning steel bolts into alloy housings, so don't over-tighten, just enough is enough.

Cheers

Very handy job description there. Cheers!

I'll do the next one myself!

Cheers,

GK

[GK]

Originally Posted by cjf

Looks like your thermostat top housing is corroded where the small breather hose sits, take off the hose and clean up the metal pipe with some fine wet and dry paper and trim hose back 10-12 mm and refit hose with a smear or engine silicone around the hose pipe to seal any pitted areas in the metal. Or just buy a new thermostat housing at supercheap or repco or similar parts store and fit it with a new thermstat while your at it.

More good advice!

GK

[ThePistonHead]

Originally Posted by 4ford

ThePistonHead...
I've recently done that same job on my S2 6.

The replacement O'ring is available at your Ford dealer, very cheap...

The job..with the engine cool or cold, depressurize the cooling system by removing the radiator cap on the expansion tank.

If I recall, it is a 10mm open-ender + 10mm socket you will be needing.

Be prepared to plug the black pipe as you pull it out, or you will lose a lot of coolant.(no pressure, just gravitational flow!).

You will need to remove two 10mm bolts, one at the leak site, and the other a few centimeters down the black pipe, a pipe mounting bracket.

This mounting bracket will be the one to cause some minor problem during reassembly, it's a realignment problem, just need to get things back in line to get the bolt back in.

Don't forget to remove and clean out any remains of the old seal, and make sure the new one is liberally covered in some coolant when you fit it on the pipe, AND when you fit it in the housing.

That's all there is to it, top up your coolant, clean off all the old leaking coolant marks, and check for leaks, job done!

Note: Don't forget you are tensioning steel bolts into alloy housings, so don't over-tighten, just enough is enough.

Cheers

Excellent advice, very much appreciated! What is the o ring called? Thermostat o ring? I'll give it a go during the weekend with a print out of your instructions next to me!

Cheers.

[ThePistonHead]

Originally Posted by cjf

Looks like your thermostat top housing is corroded where the small breather hose sits, take off the hose and clean up the metal pipe with some fine wet and dry paper and trim hose back 10-12 mm and refit hose with a smear or engine silicone around the hose pipe to seal any pitted areas in the metal. Or just buy a new thermostat housing at supercheap or repco or similar parts store and fit it with a new thermstat while your at it.

Cheers mate, ditto to you.

Will do, thanks!

[wesomc]

I'd go the new thermostat housing as half the time they leak around the joint where the outlet is glued into the alloy housing.

Wes

[ThePistonHead]

If someone's got a part name/number that would be great.

Cheers.

[cjf]

Just go in and tell the parts guy your Car model/year /engine size.
Thermostat housing and seal plus a new thermostat should be all you need, but you could whack some new hoses on while your at it if they feel soft or are bulging near the ends.

[frd906]

I done a full hose kit for my au, cost me 150, came with all the hoses i needed plus clamps etc, thats was through auto barn,

But only do that if need be, reason why i did it becuase i did a engine swap and its a ***** to get to some hoses

[JMO]

Part number I have is: AU8K540A and is about $3.00. It's the same o ring that goes into the back of the water pump.

[4ford]

That's because it's the other end of the same pipe!