Help - oil tank / thermostat

hot66 · Post by **hot66** » Tue Mar 04, 2008 5:40 pm

Anyone have any tips on undoing the 36mm nut that connects the thermostat to the oil tank ?

At the moment it is refusing to budge, even with a bit of mild heat. I don't want to really 'lean' on it in case I damage the thermostat.

Worst case scenario I can see is cutting the 36mm aluminium nut ....

Anyone know how much a new thermostat might cost? ( in case I get really frustrated

)

Gary71 · Post by **Gary71** » Tue Mar 04, 2008 5:48 pm

Picture James?

hot66 · Post by **hot66** » Tue Mar 04, 2008 5:51 pm

its this bit of the tank ( photo is a later car ) , but instead of a flexi fitting, the thermostat is directly mounted to the tank

Gary71 · Post by **Gary71** » Tue Mar 04, 2008 7:05 pm

One of my pipes to from the oil tank to the oil filter housing was stuck fast, I had to take the pipe off the tank and then the housing off the car complete with the pipe so I could attack it in the vice!

Heat was the only option, together with, how shall we say, a committed technique with the spanner.

My only fear with your pipe/thermostat is that you may end up damaging the tank.

I assume you've tried the tapping with a hammer to disturb the rust method?

Other than that... try harder...

Does it really need to come off?

hot66 · Post by **hot66** » Tue Mar 04, 2008 7:13 pm

I'm fitting a 'new' oil tank so it has to come undone. If it was a hose then I would sacrifice it , but the thermostat fits directly to the tank.

I fear if I cut the aluminium nut I will need to fit a whole new thermostat

Just been reading on Pelican that heat is a bad idea. I'll keep going using the method I am ( spanner with some sharp shocks from a hammer ) along with lots of penetrating fluid and see what happens.

hot66 · Post by **hot66** » Tue Mar 04, 2008 8:04 pm

seems the arrangment I have is again a '73 only one. I can imagine the chances of finding a one year only thermostat as being slim

here is a pic from PET

hot66 · Post by **hot66** » Tue Mar 04, 2008 8:12 pm

and here is a photo I have found :

It is the large 36mm nut you can see connecting the tank to the thermostat.

If I cut that nut, I can't see how I could install a new one onto the thermostat body???

hot66 · Post by **hot66** » Tue Mar 04, 2008 9:29 pm

here is a pic of the later type

hot66 · Post by **hot66** » Tue Mar 04, 2008 9:57 pm

Right, the big question now is, can the nut ( part 8 on the PET diagram above) be replaced if cut off from the housing?

Anyone know?

Gary71 · Post by **Gary71** » Wed Mar 05, 2008 7:46 am

James,

Is the tank and stat off the car? I guess if it is you have the stat housing secured in a vice so you can really get some torque on it. I'm till tempted by a little more heat, and maybe an extension on the spanner...

Do you need one of your burly farmer friends to come round and pull on it for you

Gary71 · Post by **Gary71** » Wed Mar 05, 2008 7:57 am

Oh yes. The question. No idea!

I would imagine it is part of the assembly.

hot66 · Post by **hot66** » Wed Mar 05, 2008 8:53 am

general opinion seems to suggest it is not wise to use heat on the aluminium thermostat nut as it also heats up the aluminium olive which then makes the joint tighter.

Also those who have used a fair bit of leverage on the thermostat nuts always seem to manage to sheer / crack the aluminium housing

Under advice from Mike bainbridge, I have left the tank & thermostat on the car at this stage as there is nothing preventing me from applying lots of leverage apart from the fear of damaging the thermostat .

Why do those simple jobs end up being a right pain in the ....

I can see this costing me some money

hot66 · Post by **hot66** » Wed Mar 05, 2008 8:55 am

Gary71 wrote:Oh yes. The question. No idea!

I would imagine it is part of the assembly.

Thats how I see it too ..... I am hoping someone will tell me differently

davidppp · Post by **davidppp** » Wed Mar 05, 2008 9:03 am

Hello..I am a bit confused here..

The nut it part of the pipe surely?

ie cutting the nut will only destroy the pipe?

I'd favour that to busting the housing threads..

heat applied very carefully and locally to the nut will work..but needs to be done very rapidly and briefly using oxy acetylen, and then use candle wax to wick into the threads.

I alos smear on moly paste..

Kind regards
David

Gary71 · Post by **Gary71** » Wed Mar 05, 2008 9:18 am

David,

I think James means this nut: