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Triumph TR6 - leaking brake warning light switch

I'm working on a '72 TR6 thats been sitting for some time (15 years).
I went through the brakes, new rubber hoses, new rear cylinders, front pades etc.. and went to bleed the brakes up, and noticed that there was a leak at a union right near the distributor. There was an electric switch screwed into the union, with no wire plugged into it, but it seemed to be the source of the leak.
Is this common?
I looked at Moss, and saw these switches for $50, which seems a bit steep. Is there a crossover part from another, british car? Or can I just plug this with a line end and a ball bearing?
Looking for an better solution than throwing down the money to moss.
thanks
Bill
Bill Mertz

Hi Bill,
What you are referring to is the PDWA switch..Pressure Differential Warning Switch and it's probably leaking from where the switch screws into the body. Mine did the same thing and since the PO has removed the electrical wire for it I removed the switch ,made sure it was dry and clean and removed the parts inside the top of the switch and filled it with construction builders adhesive ( came in a cauliking gun, I can find the name it you want )..maybe automotive silicone would work?. I did it 5 yrs ago and it's still fine
Charlie
Charlie B.

Or you can just take it apart & replace the o-rings for $1.50. The switch is not meant to be a tight seal and will leak fluid if the o-rings are shot.
Brent B

Yeah,
Did some reading in the archives, and found that the o-rings are the usual culprit. So What material do I need the o-rings to be made of in order to stand up to brake fluid and pressure?
Any good local sources in Northern CA?
Bill Mertz

There is also archives on that too. I think you can pick them up from Lowes and places. You just need the size and that is also in the archives.
don
DON KELLY

You want the EPDM (ethylene propylene diene) O-rings. If I am remebering correctly, it is an AS568 (standard number)-008 (size designator). I have scads of the things buried somewhere, but have not been able to find them. Just about any decent rubber supply company or industrial supply company (McMaster-Carr, MSC Direct, etc) should have them, but you will probably have to buy them in a bag size lot. Lot size will probably vary from supplier to supplier (25, 50, 100). Not a big deal though, they are sold in 100 count bags from McMaster-Carr and I think I paid about $8.50 for a bag last time I bought them.
SteveP

Moss part # 181-995 will fix it.
Scott

I had the same problem and new O rings solved it. If I can fix something, anybody can.

There is an older thread on this.

John.
JL Bryan

Thanks for all the responses.
-Bill
Bill Mertz

This thread was discussed between 06/05/2006 and 08/05/2006

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