B****Y External Thermostat
 

Well after a good search of the archives I have not found any encouraging advice on the removal of the caps on the external thermostat. The biggest problem people mention is removing it from the car......not for this little black duck!

So it is out...... to remove caps tried......

1. Screwdriver........NO!
2. Heat and screwdriver......NO!
3. Make tool out of old spanner with a big nut on it.......NO!
4. Heat and tool.......NO!
5. Heat, tool and impact driver.......small hammer......NO!
6. Heat, tool, impact driver and large hammer.......NO!

Frustratingly I have the new parts on the bench next to the housing, maybe santa'selves will take pity on me and help overnight.........high likelyhood of coming out in the morning to find large amounts of elf blood on bench and still not fixed.

Any help would be much appreciated.

Cheers

Mark......

Very simple, you need a bigger hammer LOL :D Seriously try soaking it overnight in light oil or oil/kerosene mix then repeat #6 as needed.

Soak threads several times with pentrating oil. Try tightening slightly and then attempt to loosen. Secure housing in large vise, use tool with long handle on cap and have helper keep tool engaged in cap wrenching feature(s). Be prepared to buy new housing as sometimes the aluminum has truly corroded together at the threads and made almost a metallurgical bond. :( Jim

Does anyone know of a source for a screwdriver type tool that would fit the slot on the thermostat? How about the slots on the pressure relief valve covers?
-Chris

Zelenda sells such a tool in 1/2" drive. It's a perfect fit for the old style, slotted pressure/relief valves on the motor. I've never tried it in the external thermostat, but it does fit in the slot.

I had the same problem those suckers are tight. I got them off by putting the thing in a vice and using a big pipe wrench. There was no way they were coming off with a screwdriver or any thing else I could get into that groove. The pipe wrench put small dents in the cap but they still worked.

Tim.

Chris,

A common 1/2"-drive 'Drag Link Drive Bit' can be ground and filed to fit the early relief-valve plugs. Final fit should be snug and precise ... without any perceptable play.

Thanks Warren! I don't know what a "'Drag Link Drive Bit" is but I'll do a search.
-Chris

"We raised 'im same as our other kids but somewhere along the way that boy went metric. Sigh."

A one inch drive drag link bit for a Cat ore transporting dump truck might be the right size to adapt to fit the slotted covers on the external oil cooler housing thermostat.:D Jim

Very funny.:)

These indeed is a crappy design. Too bad there's no replacement caps without this slot...

-Wayne

Do you have a vise? Try putting it in that, use large vise grips on the end caps turn the vise grips, but also have some one use a large screw driver at the same time if you can, requires a lot of strength... :)

Also work out what your time is worth to you, sure the external thermostat is expensive but there is no guarantee that you won't strip the threads, or that a rebuild will even work!

OK......thanks for all of the advice. As I mentioned earlier I made a tool, which is a perfect fit. So the threads must be really corroded together. Instead of using large vice grips...last resort as it will damage the cap, the next plan is to go to my local welder man. He is very good! and see if he can weld a big nut onto each of the caps.

If this fails then the vice grips come out.......failing this my next method is to launch the housing high into the air and as far as possible.......accompanied by some choice magical words. If nothing else it will give me a bit of satisfaction.

Cheers

Mark....

best be careful, mine are made of an alluminum alloy of some sort. When I finally got the caps off they were feather light. The easy part was getting them off, the toughest was putting them back on. But then again I left the thermostat in the car.
Tom

OK.....there are off!!! Finally, I just used a large stilson wrench and a four foot bar. I hate to think how much pressure was on the cap. It has been a bit mangled by the jaws but it is now rebuilt and looks fine after a bit of a cleanup with a file.

Thanks for the input and support.

Cheers

Mark.....