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TR2/3/3A Last TR3 ?of the day - fountain of brake fluid

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tdskip

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So I have a new set of calipers on order (thanks guys) but I'm still having trouble with the master cylinder leaking fluid from the TOP of the reserve. Which is weird.

Pressure seems OK, and fluid is new and system is otherwise in OK shape.

Any ideas?
 
My weak stab at it ... check if there's a "breather" hole on top of the reservoir? And a hole in the liner inside the cap?

Tom
 
PS - in my case, fluid would get up between the liner and the cap. Pressing the pedal, then quickly releasing, would push the trapped fluid up and out the vent in the cap. Like condensation on the reservoir. A mini fountain?

Tom
 
Hi Tom - thanks for the help.

There is a breather hole in the top cap. I am imaging that the same thing is happening in my car.

How did you fix the issue in your case?
 
Two things fixed my problem: the fluid in the reservoir was actually too high, nearly to the top of the cap. I removed about 1/4 inch so the fluid level only reached the base of the neck. Also, that liner under the cap was cardboard. I removed it, as I found no reference to a liner anywhere. Left the gasket, but removed the cardboard. Maybe not correct, but those two steps ended my "squirt" problem.

Hope this helps.
Tom
 
Andrew Mace said:
How new (or newly rebuilt) is that master cylinder? I wonder if it might be failing internally, enough to cause pressure to force fluid back into the reservoir?
Click to expand...

It is a new master cylinder - installed before I bought her.
 
NutmegCT said:
I removed about 1/4 inch so the fluid level only reached the base of the neck.
Click to expand...

My fluid level is already below that, so no dice there.

I'll have to look again at the cap. I don't remember there being anything under the cap.
 
There should be both an internal panel (so two holes) and a rubber gasket under the cap. The rubber gasket comes with the proper Girling MC rebuild kit (but lots of places apparently sell kits without the gasket).

Do you have to pump up either the clutch or the brakes ? That was what caused the problem for me. At the time I thought it was a problem with mis-matched components (but turned out to be a broken taper pin) ... anyway, I had to pump the clutch pedal to get it to release. When I released the pedal, the "pumped up" fluid would fountain up from the bottom of the reservoir, and get blown through the vent holes.

Oh yeah, I'm assuming we are talking about Girling brakes. The Lockheed system has problems of it's own.
 
TR3driver said:
Do you have to pump up either the clutch or the brakes ?
Click to expand...

Yep. The pedal is soft on first press but once pressed, and then released, it is then nice and firm.

This is a Girling system.
 
Randall - is there some picture or detail on that "internal panel" you mentioned? All I had was a cardboard circle, what you'd find under just about any jar or bottle lid. And there was a very rough (like punched with a nail) hole going through the cardboard.

Tom
 
The panel I'm talking about is metal, an integral part of the lid. Here's a few photos that hopefully illustrate. Obviously there are two different caps here; I'm not sure when the later style came in, but the unpainted one is original for an early TR3A, I believe.
 
Thanks Randall. Looks like I've got one more "not quite traditional" part to replace.

Sorry for the focus (my cam won't get close enough), but maybe you can see the old cardboard liner in the cap. Also, the "plain" cap (no stamping) on the outside. Looks like someone just took an awl and punched through from outside to inside (as the cardboard was "flared" from outside to inside.

What's the diameter of that rubber gasket? Mine is 1.75". Wondered if I've got a non-standard reservoir too. If it's just the top that's wrong, I'm pretty sure I can find a proper replacement. Oy.

Tom
 
Andy - you're probably right. There was lots of, er, creativity in TeeYah's past.

However, now that I've done a great job of hijacking TDSkip's original thread, maybe I'd better move this all over to the "Junk parts and cheap fixes" area?

/bcforum/images/%%GRAEMLIN_URL%%/laugh.gif

Tom
 
NutmegCT said:
However, now that I've done a great job of hijacking TDSkip's original thread, maybe I'd better move this all over to the "Junk parts and cheap fixes" area?
Click to expand...

No worries! We're all in this together...
 
NutmegCT said:
Sorry for the focus (my cam won't get close enough),
Click to expand...
Check your manual, if you have a 'macro' mode. Mine does, but I'd sure never find it without the manual! Turns out you press the 'pan left' button while in picture-taking mode, and an icon of a daisy appears. (My photos are blurry because I used ambient lighting and my hands aren't steady enough.)<div class="ubbcode-block"><div class="ubbcode-header">Quote:]What's the diameter of that rubber gasket? [/QUOTE]Sorry, had to go to work, and tonight will be very busy packing for a trip. Maybe someone else can help out.
BTW, be sure you get the right kind of rubber; brake fluid will attack many common rubbers. EPDM will do, I think.
 
So after checking everything out again this AM I have a cap like this;

8544.jpg


But no gasket(s) inside the cap. Think the missing gasket is all that is producing old faithful?
 
startech47 said:
If you have air in the braking system it will burp back.
Click to expand...

Ah.... so the leaking caliper is letting air in the system which is why the brakes are spongy until the second push of the pedal, which results in a burp that forces the fluid out the top?
 
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