View Full Version : TR2/3/3A Oil Pressure Gauge Leak - Leather Washer?

05-27-2014, 11:16 AM
Hi guys

I am having a leak behind my oil pressure gauge. I see Moss has shows a leather washer between the oil pressure line and the gauge. Is anyone familiar with this? I'm sure I did not install a washer in this location (I know, seems obvious now). I'd just like to hear from the informed collective.

Thanks - Ran my new engine for a half hour and got it hot enough to cycle the Spal electric fan a few times. Worked beautifully. I was surprised to seen the idle drop down a bit when the fan load kicked in and the Bosch alternator had to work a bit.


05-27-2014, 12:27 PM
Definitely needs to be a washer of some sort there, or it will leak. I'm pretty sure I used nylon last time, didn't know of a source for the leather and grabbing a nylon washer was easier than trying to make one from an old belt.

05-27-2014, 12:53 PM
I made a few from leather. If anyone needs one, PM me.

05-27-2014, 02:36 PM
Likely not too hard to make from leather. I believe I bought one from TRF when I was placing an order. Might an o-ring (nitrile) work as well? Cheers, Mike

05-27-2014, 02:50 PM
O ring will work; nylon washer (#6) better; the original leather type is OK but if you make your own, be sure it's thin enough.

05-27-2014, 04:51 PM
I used the original 45 year leather washer. No leaks....knock-on-wood

05-27-2014, 05:30 PM
The TR4 uses the same leather washer. When I put my gauges back in I used the original also, but on my next Moss order for other parts I bought a spare. Can't beat the price of $0.45

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05-27-2014, 05:56 PM
This is good info guys.
Looks like many of you use the leather washer. For less than 4 bits, I'll let Moss send me one!.
Much appreciated.


05-27-2014, 06:23 PM
Like you, Pat, I didn't know a washer was supposed to be there. I tightened it down and it quit leaking. I've been meaning to go back and add it...for the last 3 years.

05-27-2014, 06:24 PM
The TR4 uses the same leather washer. When I put my gauges back in I used the original also, but on my next Moss order for other parts I bought a spare. Can't beat the price of $0.45

Was it actually leather?

05-27-2014, 06:27 PM
Might an o-ring (nitrile) work as well?
Might, but I've had problems trying to use O-rings in similar situations. The problem seems to be that O-rings are soft and will stretch/deform under pressure unless they are constrained in all directions. They need to be installed into a groove to seal against pressure.

07-15-2014, 07:48 PM
Just a final follow up to this thread. I am running a SS flex hose to my oil pressure gauge (purchased from Ted at TSI). The flex hose has an adapter to attach the flex hose fitting to the gauge. I purchased a $0.45 leather gasket from Moss and installed it between the adapter and the gauge. and Voila, no more oil leak behind the gauge.

So yes, I think that the leather gasket does the trick!


10-18-2015, 12:53 PM
Members, I recently purchased a 76 TR6 and have noticed that there is oil behind the glass on the oil pressure gauge. I have removed the gauge, and have disassembled the unit to see if there were any obvious leaks. The leather washer was in place. There was nothing visible to the eye. The car has not been started in 5 years. How would I test to see if the oil in the gauge was from a loose fitting/connection, or from the actual pressure mechanism? Also any suggestions on what product to us to clean the gauge face and interior. I do not want to damage either. Thanks for the assistance.