Thermostat housing

Hi all,

I have read all the topics on Thermostat replacement here - and am at least slightly bouyed by the fact that I am not the only one to experience such issues.

I have tried

a) WD-40 to loosen the housing from the bolts, spraying it every day and tapping with a hammer.
b) A chisel to try and get a gap between the housing and the block
c) Getting a blow torch and super heating the bolts for 5 mins each, as well as heating the housing. Tried to heat and tap with hammer. Also tried to heat and then throw water over to cool it quickly and tap with hammer.

All this, and I have water coming out one side of the housing.

I have removed the hosing, and it looks like the neck of the thermostat housing is quite weak anyway... so...

How hard would it be to just chisel the whole housing (and smash it into itty bitty pieces and then throw it against a wall and take great pleasure in showing it that I will beat it)? I figure if the housing looks a bit weak I would prefer a new one... but I just don't know if chiselling it with a cold chisel will be a day long process?

After all this, I am hoping the thermostat is at fault...

Cheers!

A small air powered chisel would chop it up faster.

Just be careful of the mating surface on the cylinder head - you do not want to get chisel marks or gouges in it. Other than that - have at it!

If you are willing to sacrifice the studs, have you tried turning them with a pipe wrench (stillsons)? But be careful - you do NOT want to break them off!

I used various penetrating fluids to loosen the seized housing, along with flat screwdrivers to wedge in and pry the housing up. Eventually this worked on 2 of the 3 studs, but snapped the third one flush with the engine block. This has to be drilled out taking ages and never did completely come out. I ended up smashing the housing with a hammer to get it off and then replaced it and the studs.

Yeah, I figure that water coming out one side might be enough to get a putty scraper in there (as suggested somewhere on here) and then get some more space. I am still at a loss as to what is keeping it there. I certainly saw rust be removed on one bolt and there is now a clear gap - but the others look completely bonded with the thermostat housing... which is the only thing making me worry about chiseling the housing.

I would take the bolts out and all - but think that drilling into the block is going to cause even more issues.

The amount of deposits which have obviously come out of the gasket join previously and spilled onto the engine block - it makes me think it has been quite some time since it was off. I think from now on I will take this apart yearly (and flush the radiator too).

Using a modern anti-freeze helps too. The problem you are having is caused by galvanic corrosion between the steel of the head and studs, and the aluminum of the 'stat housing.

Keep at it - you'll get it!

Eric is right! Corrosion is ALWAYS a problem when you mix water, heat and dissimilar metals.
Have fun

give some thot to replacing the studs with bolts, cleaner look.

If destruction of the T-housing is in the works, would drilling and tapping the top of the housing then screwing a slide hammer in to apply some appropriatly directed force work? Or even more simply, drill a hole in the top then fishing a bolt through the hose outlet to attach to. Perhaps use a comealong to apply some steady strain then tap with a hammer to "warm up" the housing? Chisels and cutting tools near mating surfaces make me nervous.

A vacum cleaner or a magnet on a stick run into the hose outlet should catch filings.

K.Mott
'79 B Pertronix, HIF's, Z-car wheels, Jeff's distributor, straight exhaust
'69 B GT Pertronix, 15" wire wheels. Awake after a 20 year nap.
OKC OK

I had the same issue earlier. I bought the elbow from Moss, called their tech department, who said just patiently keep banging it until the metal-to-metal bonding lets go. Well, it took a lot of patience and maybe close to an hour, but it worked, the housing elbow came off, I put theirs on with the gasket, and all was good. BTW I found I didn't even have a thermostat ! Also, put a socket over the bolt to help save it while banging.

It is slowly coming off...

I would prefer a new housing even if I get it off (semi) graciously.... I hope it is the thermostat at fault after all this - I have concerns that the radiator core needs replacing - just by the colour of the water coming out...

I have seen a lot of people warn others off using the cork gasket - is there any particular reason why people have an aversion to using this? Is this because the cork will degrade?

Well - I finally got so sick of this I decided it was time for the cold chisel to come out... it didnt give much of a fight until I had to get it off the bolts still - where the blow torch was still needed to get movement...

Just awaiting my new housing to arrive in the mail now.

Any suggestions re: cork, I am willing to listen to still! I am certainly going to replace the nuts and coat everything in WD-40 on a regular basis from now on.

Check out the corrosion on the housing... the water is filthy too, need to flush the radiator.

The thermostat is indeed the issue too - I popped it in boiling water and it didnt do a thing. No visible leaks with it though - any one know why a thermostat would fail other than a leak? Surely the melting point would stay the same...

A very light coating of anti-seize on the bolt shaft and threads will help.

You can buy a new housing for pennies.

What is your original problem???? Leaking Water or Overheating????

I saw that you were leaking water, BUT..... Do you also have an overheating problem too> Is that the reason for the removal of the T-stat??

If so, this is what I would do. I would first order a new housing. You can get one from Moss (or distibutors) or just try eBay. I found a beauty on eBay last year. A BRAND NEW NOS one in the original BMC box from back in 1966. It only cost me about $20. I'm using it for my restoration.

But, you can find good ones for $5 on eBay everyday.

Then, I would test the T-stat in boiling water, see if it works.

If it DOES WORK, then you need a new rad. If it doesn't work. Replace the T-stat and see if your Overheating goes away.

Generally, if you have that much corrosion on the T-stat housing its because the DPO didn;t run a proper 50/50 mix, in fact, it looks like it may have not seen even a 1/99 mix of antifreeze to water.

It's quite common to see this sort of thing.

Make sure your get the surface of the cylindr head nice and clean and use a little goo along with a new gasket and you'll be fine.

50/50 mix is very important!

Thanks Brian,

The issue was overheating due to the thermostat not working - I have a new thermostat ready to go in for the last 3 weeks - but couldnt get the housing off at all due to corrossion...tried every trick int he book - and decided with the sun out now and the great days ahead, and the poor condition of the housing, to just get rid of it.

There is plenty of buildup/desposits in and around the thermostat/block - what can I do to get rid of this (if needed)?. Yes, agree on the 50/50 mix... I am ensuring that is done - but I dont think it was always the case...Anyone know the volume of a radiator, so I can get my 50/50 mix right?

I'm confused. My thermostat housing is cast iron. Are the ones for European/Australian cars aluminum? I now they are different since they don't have the bracket for the air pump, but I didn't think they were a different material.

Leighton: may pay to also check your heater valve. If your thermostat housing is in a sorry state then your heater valve may not be far behind and if it starts leaking well the dizzy is right underneath.

Russ

Andrew, I replaced my original smog pump housing with a UK-type housing to get rid of that bracket and it was an alloy of some type, not cast iron.

Don't ask why, but each time I replace, flush, clean out the radiator I remove the housing. Ask me why? Well for the simple reason I've gone thru this. So whenever I flush, off comes the Tstat housing. Gaskets are cheaper than the housing.