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Two Brake Issues for You Experts!

1571 Views 7 Replies 4 Participants Last post by  Anfanuts, 
Anfanuts
Need some help to get my beast going well again please.

1. What is the best solution for the situation where brake fluid starts squirting out of the top of the R/L imbalance detector switch located on the brake hose junction tree (that cast steel "H" dealie on the firewall with the two brake light switches out the sides). We tried a cannibalized switch and it failed also. Someone said the tapered internal slider needs new "O" ring seals. Has anybody rebuilt one of these. Any leads or other solutions?

2. Who has a solution for failure of the seam on the brake vacuum line check valve (aluminum casing) that attaches to the bolt on the first booster. Mine appears to be leaking (sucking) and affecting idle.

Thanks for your expert help and advice. Bruce
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BlpltGTV
I have had both of these problems. For the distribution block, if its leaking from one of the switches, you need to replace the switch. As for rebuilding the center piece, it shouldn't be to hard, its just got 2 small o-rings on it. The sucking noise is either a bad check valve in the intake or the vacuum valve in the booster.

To get the distribution valve out, the cap unscrews and you can pull the guts out with a set of tweezers.

Will
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Anfanuts
69 Brake Woes

BlpltGTV said:
I have had both of these problems. For the distribution block, if its leaking from one of the switches, you need to replace the switch. As for rebuilding the center piece, it shouldn't be to hard, its just got 2 small o-rings on it. The sucking noise is either a bad check valve in the intake or the vacuum valve in the booster.

To get the distribution valve out, the cap unscrews and you can pull the guts out with a set of tweezers.

Will
Click to expand...
Will, thanks for the ideas. Neither brake light switch (on the sides) is leaking. It's the distribution block's top-side Frt-Rear system imbalance switch, squirting right out. Same with a replacement (parts car) switch. Seems like the switch should hold pressure and not just rely on the lateral "o"-rings. Anyway. Any suggestions on the right size, material or supplier for the two "O" rings? I imagine this would be a good application for a dab of brake system grease also upon reassembly.

On the sucking sound, I have two new Bosch boosters ($$$) so I doubt (hope) it's not that. The aluminum-bodied check valve crimped-seam body leaks at the crimped seam. I took it off to clean the gunk out and it was loose (spinning). Tried to tighten the crimp joint but with no luck. I guess it just needs some chewing gum or RTV. Is there any supply for these check valves around? It's a fancy holed attachment that the hose fittings attachment bolt goes through.

I've read many a thread on 69's where the boosters were being abandoned or bypassed. This is real tempting. Sooo close now, just these two issues to sort. It's a very finicky system. Next time it goes down I'll chuck it.

Thanks a lot, Bruce
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papajam
Anfanuts said:
Seems like the switch should hold pressure and not just rely on the lateral "o"-rings.
Click to expand...
With a properly functioning Brake Pressure Differential Valve (BPDV), the differential electrical switch (the switch on the top of the BPDV) is isolated from the hydraulic system. As such, it need not be pressure rated (and probably isn't given the number of switches that leak). The root cause of the switch leaking is the o-rings on the BPDV pistons. Suitable replacement o-rings should be fairly easy to find.

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Anfanuts
That's the Bugger

Thanks all.

Off to the special grocery store tomorrow for some "o" rings and a dab of brake lube.

Any ideas on that pesky but necessary little aluminum-bodied check valve?

Bruce

EDIT: 16 Nov. - PS: yours may be o-rings but the seals on mine are very small cupped seals like on the MC. Looked like that on the photo above also. Perhaps an o-ring or two can be substituted. So, off to that special grocery store . . .
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Anfanuts
Follow-Up

Anfanuts said:
Thanks all.

Off to the special grocery store tomorrow for some "o" rings and a dab of brake lube.

Any ideas on that pesky but necessary little aluminum-bodied check valve?

Bruce

EDIT: 16 Nov. - PS: yours may be o-rings but the seals on mine are very small cupped seals like on the MC. Looked like that on the photo above also. Perhaps an o-ring or two can be substituted. So, off to that special grocery store . . .
Click to expand...
1. Does anyone have a source for the o-rings or cupped seals for this shaft? I've got a spare apart and ready to go.

2. Does anyone have any leads on that pesky little aluminum-bodied check valve, Mine was wobbly and turned around in the crimped joint and aluminum does not re-crimp so well. Tried JB Weld,, Mechanic says it's causing #4 to jump.

Thanks in advance.
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Andrew
The check valve is the same on Spica and Weber-equipped cars. The crimp frequently loosens over time, resulting in what you see; I have a couple loose ones. I'd think any number of Spica manifolds lying around would have the check valve. Call APE (209) 833-8330.

Andrew
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Anfanuts
Thanks. The check valve on a 69 US is actually integrated into the longer aluminum banjo fitting to the first booster using the longer bolt. It has another brass banjo that sends vacuum to the 2nd (front) booster. May need to tind an in-line check valve/ Will call the usual suspects.
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