14 replies to this topic

[IainR]

Just taken the head off the engine and have undone the three nuts holding the thermostat housing on but the housing is stuck fast.

I have applied WD40, tried heating up the studs and hitting it with a rubber mallet but it is stuck fast, any other suggestions how to shift it without damaging it?

Edited by IainR, 22 November 2010 - 08:45 AM.

[Big_Adam]

They can come off without braking them?

Also, do you HAVE to take it off? I never gotten one off without a hacksaw or just smashing it.

[AVV IT]

I removed mine by drilling the studs out, obviously you risk damaging the housing if you slip with the drill (which you inevitably will) and then you also have the added problem of extracting the remains of the bottom of each stud from the head. Personally if I were to ever do it again, I would probably just cut the old one away and then buy a new one. Which ever method you choose, to prevent a reoccurrence be sure to coat the threads with copper grease when you refit the housing and preferably refit using stainless studs Like These as well.

[toyboy396]

When that happens i use a hammer................and wallpaper scraper.. Gently knock it between the housing and head.

[asmith88]

ive never had a problem with them, in fact i did one the other day which was a little stuck, but it soon levered off with a little tap of a screwdriver

[Ethel]

Try welding, or gluing with thread lock, the nuts to the studs so the studs unscrew instead. If it's an early type Mini one they aren't too expensive.

[Nu2mini]

Here's another solution.

Halfords Stud Extractor

Though I have to say I still ended up cutting mine off. All I can say is once it gets past a certain point the hacksaw is the only solution !!

[IainR]

Thanks guys, I thought the Dremmel / hacksaw was going to be the solution.

I'm going to order an exchange unleaded head, might wait until it comes in to see what I need to remove, might be easier / cheaper to buy a new housing and send the old one off with the housing still stuck on.

[yousmeg]

I had this problem... so i didnt take it off

[frenchie851]

do you need to drain the cooling system first?

[L400RAS]

do you need to drain the cooling system first?

I syphoned the water out the top of the rad, then when you disconnect the top hose and remove thermostat / housing, you lose minimal water.

You could disconnect the hose to the waterpump. This would drop the water level far below the thermostat, however you will lose a lot of water.

[peterwalsh]

The housing on my Mk1 would not budge. I sprayed liberally with liquid plumber, which I find vastly superior to WD40. I left it for a week. Then sprayed again and left for a few hours. Whacked it with a mallet repeatedly in as many different directions as I could. After a good 5 minutes of whacks I was able to slip a paint scraper in one corner and then worked up to a wide a screwdriver.

[Steam]

A standard fault that occurs when your cooling system water becomes alkaline, and attacks any aluminium parts. The Tstat bousing is an indicator of more problems like water pump etc.
The housing is probably shot internally anyway so you may as well cut it off and fit a new one. Then replace your coolant with fresh and keep an eye on the alkalinity of you coolant.

[68+86auto]

Remove the studs and then it'll come off.

[PoolGuy]

I have applied WD40, 

Try Plusgas, WD40 isn't a penetrating oil