Morris Minor Forum

the first stud wound out, two more to go.

the rubble that was the old housing together with it's new replacement. More tomorrow.

I think I would have extracted the studs with double nuts before destroying the cover and the studs as shown weakened by the cutting blade...but it seems you did get the old one off as your prime objective.

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I've seen better days but they have cost me more money..!

5 out of 5 people usually think the other 4 are idiots....

If you always do what you always did you will always get what you always got.

It's not uncommon for those studs to corrode in place and there is no way to remove the studs first. The corrosion bond is too strong. It's recommended to coat the studs with grease to isolate them from the dissimilar metal of the cover.

How did you mount the back backwards with the non-flat shape where it bolts to the hub?



Edited 1 time(s). Last edit at 2025-09-23 12:08 PM by emjay.

the image is fairly typical.. removing the old studs without snapping them can be a challenge.. if you have a plumbers torch and mapp gas ( burns hotter that propane/butane) then heat each stud untill it is bright red.. let it cool..soak with a good pentrant and whack the end of the stud hard with a good sized hammer to jar the threads .. let it sit for at least and hour..( if you can..soak it with pentrant again and let it sit overnight) then re-heat and see if you can get each stud to turn with either stud extractor or some vice grips... dont be afraid to re-heat.. and work the stud back and forth a little at a time, to minimalize the prospect of it snapping...its challenging to drill a broken thermostat stud out accurately without having head in a drill pres, but it can be done with skill and patience.. .the threads in head for tap are 5/16" NC (18 tpi) good luck..

Thanks for all the interesting and helpful comments Gents.

The second stud wound out like the first, with two nut bound together routine, but the third looked like a different prospect. the shaft and threads were badly damaged, too bad to lock two nuts tight enough to wind it out. So after a fire precaution,(that float bowl still holds petrol). Welded three spots of weld on the top nut welding it to the stud. like this. and with a squeek it wound out, to great satisfaction and no small amount of relief.



Edited 1 time(s). Last edit at 2025-09-24 08:17 AM by David JM.

so, three studs out, clean up the rim and take care none of that debris falls into the void, time for a Bacon Roll and a Mug of tea.

Good work.. looks like you got em all out cleanly. Welding on a nut commonly does the trick on a rusted in stud.. the heat from the weld has similar effect on the threads to heating the stud with a torch..

Thanks for all the help and supportive comments with the Thermostat housing studs all, much appreciated.

the studs in and the housing tightened up, used some gasket paste on both sides of the gasket for good measure.

went on a test drive to get the thermostat up to temperature so I could check for leaks, none on the drive, and the bowl I placed under was bone dry, so I'm going to monitor the coolant situation, and carry out my usual routine pre start checks, but it's all looking good so far.

looks to be a job well done..preventative maintenance at its best and likely good for another 59 years ..I do wish that someone would make some thermo studs out of Stainless steel .. though one can use 5/16 X 18NC stainless bolts.. a little tricker to align housing and gasket, but easier to remove.

Next issue is the fuel pump, it's not an SU, in fact I've no idea what make or model it is, but it's over delivering and overwhelming the float chamber. SO I've renewed the float bowl lid, float and valve. it's not stalled since but I occasionally get a whiff of Petrol, so that pump has got to go. A new SU ordered from ESM.

Did you use a 'viton' tipped float valve ? (they tend to be more effective at regulating fuel level) the blue 'hardi' pumps ( ESM also carry them) whilst being superior as regards reliability, tend to put out a little more pressure than the original Skinners Union device and its highly likely that other 'aftermarket' pumps would do the same ..
another common issue is that the brass floats ( only in pre '59 cars with H1/H2 carb) ) tend to suffer break down of the solder due to ethanol in the fuel here in USA.. and then they leak and fail to float .. the plastic floats in the HS carbs can and do fail too... solid 'nitrophyl' floats are the cure..

As to Timothy's remark about Hardi fuel pumps, I installed one in 2014, and it crapped out this year. The diaphragm was torn in a couple of places even though the unit still looked brand new. It might have had something to do with the ethanol that California adds to the gasoline. I replaced it with another Hardi pump because the SU was going to be almost twice the price. Hardi can recondition the pump, but that involves paying shipping both ways to Germany.
I didn't want to hijack David's thread, but just wanted to put that out. Good work on your car, David.

Another Hardi pump experience. I tried one in the Seventies. The diaphragm's six screw holes match the SU diaphragm, so I mounted it to a SU pump body rather than changing the fuel supply line. It was always a source of problems and just didn't like warm temperatures. The final straw was when it was just pumping air but would still work when cooled down. The theory was there was a small hole(s) in the diaphragm that leaked when warm. Only used rebuilt SUs after that.