Brake Gurus chime in please
- Thread starter 66furys
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Gerald Morris
Senior Member
Raybestos is now sino-crapitalist owned. Don't buy their excremetal again bro. There are plenty old master cylinders still out there. Those directions for the bench bleed were composed by an idiot or malicious prankster. See if you can find a Bendix, or even a Bendix knockoff. Mine still works and I now have an old reman to restore for when that one gets bad. I now have all NOS wheel cylinders to put on as well, and will, the first sign of trouble from the sino-crap the flipper had installed before I got Gertrude.
Blessings on you and your work. Brakes can't be trifled with.
Gerald Morris
Senior Member
Right ON! That's the Way we do it here too. Straight manual brakes are the most reliable. Even when boosters work, they rely on heavy engine vacuum.
Hilarious.....sino crap. I remember the first japanese stuff coming in.....the little umbrellas for drinks and cars that would fit in a shoebox, the early hondas. But, that all changed when they got their stuff together. One of the funny things from china are their tools, that have no decent steel and will crack and break at any tough use. The Taiwan tools have mostly been OK, and of course, they are ROChina. But, on the other hand, some of the most sophisticated electronics including the IPhone, 5G, AI, solar panels, and the best semiconductor chips....from china. But, when they cut corners, they just dont give a damn. I think they have known better for some time.....kinda like the military will learn if we start WWIII, after some hypersonic missiles target some carriers. Both china and russia have them, and we cant get them to work.....another failed test last week. But, when we want some of this hardware, you find that we just make anything today. That is the disaster. I came across a great video of a small repair guy who does the old mopar masters....and will review.
volksworld
Active Member
about 3 yrs ago had an issue with my son's jetta...kept using fluid with no visible leaks...so obvious conclusion was leaking into the booster...bought a Raybestos mc...ps inside of the booster was dry, and problem was later isolated to a rear caliper...but a year later the brakes seized up completely, the master was defective and there was a recall on it and rock auto guaranteed it... found out through the recall notice that the master was chinese, sold by Brake Parts Inc and marketed as Raybestos, NAPA, and AC Delco...when i posted a warning about the master on a VW site they gave me crap about using "second rate american parts"
fury fan
Senior Member
Ordinarily I agree with you, but I disagree on one thing here.
Air molecules are smaller than liquids, and an air leak may not always manifest into a liquid leak.
I have seen this happen in a hydraulic system on a utility truck, where a suction-side hose/fitting was allowing the pump to suck some air and cavitate.
(the suction side had a long uphill draw, so an air leak on the fitting was less resistance).
But it did not leak any fluid, despite some decent head pressure from the tank onto that same fitting, and it was thin cold-weather fluid (ATF-like viscosity) too.
I don't know how the molecules in brake fluid compare to petroleum-based fluids with chain-molecule additives, though.
OK I saw the comment from Davea.....but, I have spent some time checking each fitting that was opened, and the lines. Also, I have checked the level in reservoirs looking for problems. I have only found one fitting that was weeping, and tightened. But, IF a wheel cylinder is leaking a bit, it might be held inside the boot. But, so far, I have inspected, removed drums after new parts, etc and not found leaks...not to say that there may not be one somewhere. I do not understand what might happen with a bad seal or cup inside the master, but some say that if the pedal is acting strangely, it can be this. So, I am headed to rebleed the master once I get the proper line nut in 20 thread, and am also going to talk to a virginia rebuilder of note, might need sleeving?? for the older master. So, I am going forward....do not know what in the world is going on yet.
If you are still running the OEM style single pot master cylinder, take it off and check the discharge port for cracks. These sometimes cracked and would ingest air into the system, especially if the master is the dual port type. On a '66 the second port is blocked off by a plug and they would crack between the blocked port and the discharge port. On earlier models the second port was used for a pressure type brake light switch.
Dave
fury fan
Senior Member
I would need to read all of this more critically to see if it's been mentioned already:
If you have new(er) hoses that aren't brittle, you could use hose pinch-off pliers on each one and see what happens. (gotta do all 3 at same time)
If you get a rock-hard pedal, on each push, your MC and circuits (up to the pliers) are good.
You could do this with plugs on the MC, of course, but then you're into a wheel-bleed situation. The pliers give a 3-min answer.
I've seen guys do this with vise grips, and done it myself in the past, but not sure I would want to do that nowadays as there are more suitable tools.
Small C-clamps squeezing rounded-edge blocks of wood on the hose would be an improvement over vise-grips, albeit harder to juggle all those pieces.
If you have new(er) hoses that aren't brittle, you could use hose pinch-off pliers on each one and see what happens. (gotta do all 3 at same time)
If you get a rock-hard pedal, on each push, your MC and circuits (up to the pliers) are good.
You could do this with plugs on the MC, of course, but then you're into a wheel-bleed situation. The pliers give a 3-min answer.
I've seen guys do this with vise grips, and done it myself in the past, but not sure I would want to do that nowadays as there are more suitable tools.
Small C-clamps squeezing rounded-edge blocks of wood on the hose would be an improvement over vise-grips, albeit harder to juggle all those pieces.
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Thanks guys....good points to consider here. Yes newer style dual system. Interestingly enough, I cant tell if this car might have come with the dual system, as the distro safety valve looks kinda OEM, yes not supposed to be til next year. But, I think, after all of the great points and comments, I am headed to do two things....wait for the proper line flare nut to make the gooderer bleed tubes and try that, and yes with complete re-bleed. And, I have reached out to try to find a better master, maybe made here, or a good shop to rebuild the one I removed and possibly sleeve if needed. Meanwhile, I will keep the drive tests going, just in case something is hanging or sticking (not likely), but, but but. A couple folks seemed sure that it was a bad master, and nothing else yet seems to make sense. BTW, one of the unusual things is that I can sit in the seat and hit the pedal couple times and it stays tight, but driving, not so much. That has also confused the crap out of me. I have had the drums off couple times looking for something else, see nada out of line. Happy Passover.
I used short sections of hard tube, then clear plastic into the reservoirs, and had honey slowly move the pedal down. There was some air. I first let the fittings loose, and added fluid into the clear tubes until running out the fittings to try to minimize air in the tubing, so I could see if there was actually air inside the master. There was air, but after all that, I could not tell if it was a lot, or any. So, will bleed the four, then test again.
I am going to try to solve another problem that I have had.....handling the round hold down pin caps. Have always used pliers, and some time back, got the special tool that is conical, and has a couple slots thru which you are supposed to see. Well, two things, first, the ridges do not hold well, the caps squirm around and do not stay flat, and you cant see well. So, as I prep to re bleed, I also need to change these pins on one of the rear brakes.....could not find the short ones, so used a nut under the head of a long pin. So, found the short ones and need to change today. So, after agonizing, I am going to take normal slip pliers, and use a dremel grind wheel to create a rounded slot on the end of the jaws. I hope that I can make a rounded slot to hold these round caps a bit better. Pliers have always worked, but with a fight....so we will see if I can make it easier on the old man this time.
The saga continues. I bled the master using tubes feeding back into the reservoirs. Got maybe a hint of air.....not sure after the disconnects that I tried to overcome by filling the clear tubes. So, today, rebled the front and rear.....only got air from the fronts. Then another road trial. The brakes still work pretty well can almost lock up, on first brake. Then, a bit soft but if I pump once or twice, they come back up. This is a small bit better than it was, but not right. So, am more or less agreeing with the above comments on bad master.....soooo, will wait for rebuilt unit from a great shop here in Va, and will try again.
I would pull the master cylinder off the car and do the bench bleed the right way.
It's my experience where I've seen this happen that there is still air somewhere in the system. With the MC off the car, you can push the pistons to the full range, back and forth... Where on the car, I've seen where trying to bleed it sometimes works... and sometime doesn't.
I don't think it's the MC, but what do I know?
You may be right, I am losing my mind on a simple job. Followed the Raybestos recommended process first in the vise....with plugs. This time, I did use the second method of running lines back into the reservoir. Does the pedal push the piston all the way in....unknown. But, I am thinking that if there were air, it should bleed out with this method, bench or in the car by pedal. But, it still is not right. So, at this point, I will wait for the rebuilt, bleed it in the vise, and install, and start all over. Drivin me to drink.
just lightly clamp some vice-grips across the disc. push on turn and release vice grips.
the grooves in the jaws of the vice grips serve the same purpose but with more leverage.
No booster on my setup....just the new dual master and brake safety block, or distro block. So, after some time, here is where things stand. Had the older master rebuilt by White Post Restos.....great sleeving and rebuild. This time used the lines to bench bleed, and as noted above, did the bleed again after finding air sucking in one wheel cylinder during bleed. Replaced the one wheel cylinder, as noted by Big John, and also suggested by rebuilder. So, then gravity bled because my help was busy. No pedal. Got her to pump brakes later, and no pedal.....not happy. So, starting from scratch, found two wheels a bit loose on the shoes.....not much but not tight. Also, was not getting enough fluid thru rears. So, start over with pressure bleed on reservoir.....a lot of crap to stop the air leaks on the adapter. So with very low press, maybe 15 psi, began at back yet again. Bled rears and found some air in the RR. Then, the last one, LF, found a bit of air there too. So, after my trials, I have some brakes. Now what I like is a rock hard pedal. I have maybe 90% and the wheels will lock up on gravel drive now.....and need more road test to seat the new shoes. So, for today, I am a happy guy with enough brake to road test. Good thing that when I was young it was not this hard, or I would have bailed.
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