TR2/3/3A Gaskets for Brake/Clutch Fluid Reservoir?

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Bruce100

Jedi Trainee

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• Nov 26, 2014

• #1

Doesn't seem like the big three or even Moss Europe carry the flexible washer/seals for the Brake Fluid reservoir. I saw that you can buy the whole can for around $70. Was wondering if any of you had found something that works here. I went down to NAPA, and they started to look at O rings, and sold me a couple of copper washers. Went down to a hydraulic hose repair shop, but would spend a fortune on a special order sheet of brake fluid resistant material to make my own.

Thoughts?

 

CJD

Yoda

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• Nov 26, 2014

• #2

I went through that too. I wound up visiting Ace Hardware. In the plumbing aisle you can find some black rubber washers that will work. I left them in brake fluid for a week before using to make sure they were compatible.

 

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titanic

Jedi Warrior

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• Nov 26, 2014

• #3

What are the dimensions for the gasket? I may have some left over from other rebuild kits?
Berry

 

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Bruce100

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• Nov 26, 2014

• #4

Thanks Berry. The hole is 1/2 inch. I don't know what the outside diameter was. Also, do you know if there was one or two gaskets? The one I found on disassembly was under the tube that creates the second reservoir. Per below. There could have been more, but everything was pretty mushy/disintegrated.


John, I am hesitant on hardware store gaskets w/out knowing what they are made of - esp for brake hydraulics. I ran into this site in my research, and decided against just winging it. https://www.efunda.com/DesignStandards/oring/oring_chemical.cfm?SM=none&SC=Brake

 

TR3driver

Great Pumpkin - R.I.P

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• Nov 26, 2014

• #5

Bruce100 said:

John, I am hesitant on hardware store gaskets w/out knowing what they are made of - esp for brake hydraulics. I ran into this site in my research, and decided against just winging it. https://www.efunda.com/DesignStandards/oring/oring_chemical.cfm?SM=none&SC=Brake

Click to expand...

Notice the line that says Ethylene-Propylene is good for both dynamic and static seals. They're talking about EPDM, which is one of the most common "rubbers" found in hardware stores because it is cheap and resists weather very well.
Probably still best to buy from some place like MMC that knows what they are selling, but you've got a good chance with hardware store stuff.

As I recall, there were two fiber washers in addition to the one rubber.

 

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titanic

Jedi Warrior

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• Nov 26, 2014

• #6

Sorry Bruce, I was thinking of the seal in the lid. Maybe it is heresy, but I would try cutting a gasket from some heavy gasket material. I have no idea if it would be compatible with brake fluid, but the seal at the bottom of the can isn't exposed to any pressure. Of course, you don't want paint eating brake fluid dripping on body work.
Berry

 

CJD

Yoda

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• Nov 26, 2014

• #7

My "wing" washers are still fine 3 years later. Rubber that is not compatible will swell up overnight. If it's good after a week, it'll be good long term.

 

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TexasKnucklehead

Jedi Knight

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• Nov 29, 2014

• #8

Sorry I am so late to respond. I too had concerns with rubber, but had several 'good' reservoirs' that needed married to good pipes. -And I hate to buy something new when all they really need is a good cleaning and a washer. Going off memory, I used copper washers. I looked through my pictures and can't find any of the MCs, but know it was trial and error until I was able to get them tight enough to not leak. I've been driving it for over a year and still no leaks. A rubber gasket at the top is also important as fluid kept wetting the top lid and making it look like there was a leak somewhere.

I'm told the fluid level should be below the internal baffle, so you can tell when something is leaking, but I keep my fluid level just above the baffle.

 

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sp53

Yoda

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• Nov 29, 2014

• #9

Yeh I think the originals were some kind of aluminum alloy.

 

dklawson

Yoda

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• Nov 30, 2014

• #10

Randall posted earlier regarding using EPDM for brake fluid compatible rubber. It doesn't have to be expensive. I was unaware that you could buy EPDM from local hardware stores but as Randall said you can buy it from McMaster-Carr (mcmaster.com). For example, a 12"x12" sheet of 1/16" thick EPDM is less than $6. McMaster also sells EPDM o-rings which can be used in other locations but you are likely to have to buy bags of 50 or 100... which still might be less expensive than buying from an automotive supply house.

 

PatGalvin

Jedi Warrior

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• Nov 30, 2014

• #11

Bruce, I purchased EPDM o-rings from McMaster Carr for this purpose. They were a little tricky to install (they are a bit fat) and they can't be tightened and crushed like a copper or aluminum washer can. If I were to do this again, I might consider using a soft copper washer for sealing up the can bottom fittings. With the o-rings, the bottom fittings can move a bit - soft metal sealing washers would be more solid. My reservoir is leak free (after about 6 months of use). I purchased about a hundred o-rings for about ten bucks. Let me see if I can find them. If so, I'd be happy to send you a few to try.

Pat

 

TR3driver

Great Pumpkin - R.I.P

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• Nov 30, 2014

• #12

dklawson said:

McMaster also sells EPDM o-rings which can be used in other locations but you are likely to have to buy bags of 50 or 100... which still might be less expensive than buying from an automotive supply house.

Click to expand...

Hopefully this is obvious, but JIC: they do sell cut washers in EPDM as well.
https://www.mcmaster.com/?m=true#epdm-rubber-sealing-washers/=utlh6q

If it really bugs you buying a bag of 100 when you only need two; you might try giving them a call. It used to be that they would break a box for you, for a price. So they might sell you two of them for not much more than a bag of 100

 

dklawson

Yoda

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• Nov 30, 2014

• #13

PatGalvin said:

Bruce, I purchased EPDM o-rings from McMaster Carr for this purpose. They were a little tricky to install (they are a bit fat) and they can't be tightened and crushed like a copper or aluminum washer can.

Click to expand...

Since I have not worked on these early brake reservoirs the following suggestion may not be applicable but I'll mention it for possible use elsewhere.

In hydraulic circuits using straight pipe threads there are sealing washers available that have a bonded o-ring in the center of a metal washer. (In the U.K. they are sometimes referred to as Dowty Washers or Dowty Seals). On a few occasions I have improvised my own version of these by taking a regular flat washer and boring it out to fit the outside diameter of an o-ring. I installed the o-ring with the metal washer around it and tightened the assembly. The surfaces to be sealed would be drawn together crushing the o-ring until the flat surfaces of the metal washer were contacted. Therefore, the metal washer both kept the o-ring from being squeezed out of the joint and limited how much crush it would experience.

 

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Bruce100

Jedi Trainee

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• Dec 1, 2014

• #14

So an update. I have some local rubber washers of unknown composition soaking in brake fluid, waiting on results. I also bought some copper washers from NAPA. I am unsure where they were originally installed. I have a remnant of a rubber washer that was between the internal reservoir and the inside of the outer reservoir, which I think i will replace with rubber. I assume that their should be 2 more washers between male end of the fitting and the exterior of the outer reservoir? I am thinking replace these with copper.

 

TR3driver

Great Pumpkin - R.I.P

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• Dec 1, 2014

• #15

It has been awhile, but as I recall, both fittings had a fiber washer under the head of the fitting; then the "rubber" washer was between the inner chamber and outer. On the outside were just star-type lockwashers and nuts.

 

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tenderle

Freshman Member

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• Dec 1, 2014

• #16

I use Stat-O-Seals available
from pegasusautoracing.com or summitracing.com.


Ted Enderle
Seattle