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irishcasey
08-08-2012, 10:26 PM
Hi, I have oil flooding out of the end of the oil pressure switch. I'm not mechanically inclined and would appreciate any tips on this replacement.

The leak is actually coming from the end of the switch, not the threaded junction with the block. Do these just go bad or could this malfunction have resulted from a different, possibly bigger issue.

If not, it looks like Moss part number 760-200. If this is the sole problem is it a straight forward remove old switch and replace with new switch? Can I expect to loss a lot of oil upon removing bad switch?

Any help is appreciated. Thanks !!

RomanH
08-09-2012, 12:00 AM
Yes those switches do just go bad. The replacement is straight forward and no, you won't loose any oil when you remove it except for the small volume contained in the switch.
For what its worth, you can get that switch at you local parts store for less if thats all you need.
Here is a link from Autozone
Oil Pressure Switch (https://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_oil-pressure-switch-%28light%29-bwd_5971705-p?searchTerm=oil+pressure+switch#)

TR3driver
08-09-2012, 12:02 AM
:iagree:

irishcasey
08-09-2012, 08:37 AM
Thank you Romanti for the info and link. Picking up today at Autozone.

poolboy
08-09-2012, 11:56 AM
Connecting the 3 wires to the correct terminal on the switch is very important
"P" gets the Black
"S" gets the White/brown stripe
"I" gets the White/purple stripe

Brosky
08-09-2012, 03:41 PM
Here's a picture in case you can't see some very small letters on the switch. Not all switches have them.

irishcasey
08-09-2012, 09:09 PM
Thank you all for the helpful information. As you can see that was my first post. My TR which I bought in Jan 83 had been sitting for about 25 years but now its back on the road.

When installing the new switch, do you recommend putting anything on the threads prior to screwing it into the block?

Thanks all. :thankyousign:

poolboy
08-09-2012, 09:27 PM
My TR which I bought in Jan 83 had been sitting for about 25 years but now its back on the road.


I'm <span style="font-style: italic">ALMOST </span> afraid to ask....but since you brought it up....why let it sit for 25 years ?

irishcasey
08-09-2012, 10:36 PM
Good question Poolboy. Not a good answer....space, marriage, family, time. Not smart on my part but I'm looking forward to renewing the hobby and keeping it on the road. Certainly plenty to do.

Any thoughts on treating the threads prior to install?

Thanks, Mike.

poolboy
08-09-2012, 11:06 PM
Well they are tapered threads, like pipe threads, so they do a good job of sealing on their own. Don't over tighten it and if it does show dampness, tighten just a bit more.
If ever you remove it for whatever reason, a thread sealer (not thread locker) might be in order, but a new one, no, you shouldn't need anything in my opinion.

BTW most people say that, above all, the brakes need attention on cars that have sat up that long. Hope you took care of that or at least plan on it.

RomanH
08-09-2012, 11:07 PM
Any thoughts on treating the threads prior to install?

Thanks, Mike.

I have not put any anti seize or pipe joint compound on mine. Just make sure the switch is tight and it should be good to go.

TR3driver
08-09-2012, 11:49 PM
Any thoughts on treating the threads prior to install?
Opinions vary, obviously. I like to put smear of teflon pipe paste (aka dope) on anything with tapered threads. Not a necessity of course, but it does help it seal easier and come apart easier next time.

irishcasey
08-10-2012, 10:38 PM
Thanks to all.

New switch installed and no leak after brief test drive. Thanks again. Yellow oil light does not come on when key is turned to on??

Also, yes, I did have the brake hydraulics redone with new master cylinder, new lines, etc. Thanks !!

poolboy
08-11-2012, 08:18 AM
First thing I'd do is check the position of the wires connected to the switch

TR3driver
08-11-2012, 09:18 AM
First thing I'd do is check the position of the wires connected to the switch
:iagree:
But since the markings on the switch and/or the terminal position may not match Paul's diagram above, I might do some checking with an ohmmeter or powered test light. With the engine off and the wires disconnected, you should find continuity between the terminal for the black wire (ground) and the terminal for the white/brown. If not, either those are the wrong terminals or the switch is bad.

Andrew Mace
08-11-2012, 10:09 AM
Does your brake warning light come on when the key is turned to ON? With the Spitfires, the brake and oil pressure warning lights are interconnected, but I don't know if that's the case with the TR6.

irishcasey
08-11-2012, 11:11 PM
Hi. After double checking, I do have the "brake" light indicator on start up and I also have the oil pressure light when initially starting engine. The light is very faint compared to the ignition light but it is lighting.

The replacement switch had the same markings as the original P,S and I.

Thanks again.