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View Full Version : Mystery with Disappearing Brake Fluid? - Help!



studebaker-R2-4-me
06-13-2007, 07:55 PM
A couple of weeks ago I found a leak in the rear brake tee. I had taken the tee off from the hose. The little copper washer between the rubber hose and the tee was the source of the leak. I tightened the hose, copper washer and tee and stopped the leak. After about a week I checked the reservoir on the firewall and I still have brake fluid disappearing.

I have checked every brake line connection with NO sign of dripping brake fluid anywhere.

I was wondering could my Hydrovac be leaking internally and this brake fluid be sucked into the vacuum then finally be burned through base of the carburetor?

I also noticed that while bleading the hydrovac (Mine has only one bleeder) I was constantly getting air every time I brought the pedal to the top for the next pump. I was using clear hose and pumped it into a water bottle.I went through half a bottle of brake fluid before giving up.

What are the tell tale signs of a failing Hydrovac?


Allen





1964 GT Hawk soon to be R2 Clone

N8N
06-14-2007, 11:56 AM
If you're getting any white smoke from the exhaust i would bet on your hydrovac needing a rebuild. It's also possible that the MC might be sucking air.

nate

--
55 Commander Starlight
http://members.cox.net/njnagel

64V-K7
06-14-2007, 01:22 PM
A leaking Hydrovac will give you a couple problems. Leaks can occur internally (seals) that will diminish the effectiveness of the Hydro, but a bad diaphragm, will allow brake fluid to be drawn into the vacuum chamber, then into the engine. If you're using silicone fluid, that's bad, because it will turn to sand, inside the combustion chamber...

The other problem, is the vacuum leak, itself. The factory vacuum hose, from the manifold to the hydro, is right behind the carb, on the manifold runners that feed #5 and #7 cylinders. A leak in either the hose connection or the booster diaphragm will continuously bleed air into the manifold and lean out #5, more than #7. Over time, this will evidence itself with overly warm engine temps and usually whiten the tips of your (5,7) plugs. Left alone for long enough, it will eventually lead to a burned valve.

If you're continually experiencing air in your Hydro, then you have air in your brake lines too, as they get the fluid after the hydro. Make a short brake line, with two unions, to bypass the hydro and bleed the brakes again. If you're satisfied, then reconnect the hydro and see what happens. A bit of caution here.... If your brake pedal is the original factory power brake model, then you'll never stop adequately with the hydro out of the system.

How the air is getting into the hydro is another matter I'd think it has to be pumped in, to get there and the only way to do this is from the MC, however if it pulls air in, it should drip fluid out too. every connection has to be checked for fluid. That forward. frame mount, 3 way tee can be leaking and running the fluid down the frame. Since regular BF has alcohol in it, it can be evaporating before you see it, but the oil will be there...


Bob Johnstone
http://www.studebaker-info.org/7168422/sig2.jpg

GTtim
06-14-2007, 06:33 PM
Allen, take the vacuum connection off the Hydrovac, at the bottom of the Hydrovac. If brake fluid runs out, you need a booster rebuild. If none if evident then the problem must be elsewhere, like maybe a leaky wheel cylinder. Good luck!

Tim K.
'64 R2 GT Hawk

hank63
06-14-2007, 08:09 PM
If you're getting normal brake fluid into the cylinders, you will notice. The amount of white smoke coming out of your exhaust has to be seen to be believed. Been there, done that !
/H

Dick Steinkamp
06-14-2007, 08:41 PM
quote:Originally posted by studebaker-R2-4-me


I also noticed that while bleading the hydrovac (Mine has only one bleeder) I was constantly getting air every time I brought the pedal to the top for the next pump.

Can you explain this more fully? I'm having a hard time visualizing it. When returning the pedal to the top for the next pump, all bleeder screws should be closed. How do you know you're getting air during this process?



http://thenobot.org/images/s2d/s2d_01.jpg

studebaker-R2-4-me
06-14-2007, 09:15 PM
Dick,

I've used a clear hose over the nipple of the hydrovac which I have going to a clear water bottle half filled with brake fluid. I've drilled a hole in the cap of the water bottle and run the clear hose into the brake fluid. This keeps the brake fluid contained and you're able to see the air coming out of the system. You could bleed a system by yourself using this method.

http://i122.photobucket.com/albums/o278/studebaker-r2-4-me/IMGP3296.jpg



I just noticed brake fluid coming out of the vent in the front of the hydrovac. Am I looking for a rebuild?

http://i122.photobucket.com/albums/o278/studebaker-r2-4-me/IMGP3295.jpg



1964 GT Hawk soon to be R2 Clone

N8N
06-14-2007, 09:33 PM
short answer, yes.

nate

--
55 Commander Starlight
http://members.cox.net/njnagel

GTtim
06-14-2007, 09:35 PM
Allen, about your bleeding method, functionally it will probably work just fine. I do think that there is the possibility that a little air might sneak past the threads of the bleeder screw and show itself in the tube. I know it is hard to get at, but it was the connection of the vacuum line at the bottom of the Hydrovac that showed me that the booster was full of brake fluid. I never noticed any white smoke. Any brake fluid found in the vacuum chamber means the unit has to be rebuilt.

Tim K.
'64 R2 GT Hawk

studebaker-R2-4-me
06-14-2007, 09:53 PM
Thanks Tim,

Will you be in South Bend next week? I will be there between the June 19-22. If so, lets connect over a few Cocktails. Sure looks like I will be spending more money at South Bend. I have not noticed any white smoke coming from my car. I am going to pull that vacuum line and see how much fluid is in there. It's just time and money,....life!


Allen



1964 GT Hawk soon to be R2 Clone

GTtim
06-14-2007, 10:32 PM
Yes, Allen I'll be there starting Wednesday. Give me a call. If you forgot my number, send me an email.

Tim K.
'64 R2 GT Hawk