I have a 4wheel disc brake setup on my 39 Buick. Recently I had a leak coming out the bottom weephole near the booster after I installed a remote MC reservoir. Brakes bled well but MC leaked. Bought new MC, thought maybe the old(4years)MC had sat too long during project and had ac***ulated a little rust on the piston. Benchbled new MC, attempted to bleed 1st wheel(farthest from MC)...no fluid comes out??? Same in front??? The reservoir is a new VW plastic-type. Now if I try to gravity bleed that same rear caliper...nothing comes out. But if I take the little cap off the full reservoir, the bleeding tube starts to bubble like crazy and fill the attached jar. I'm trying to do this all by myself so I have no ***istent to push pedal. This is extremely frustrating because I have bled hundreds of brakejobs in my long life and never had this problem...although none with remote reservoirs until my "pre weephole" experience, and now this. Should the cap be on? There is no show of air or movement on the top of the brake fluid in the reservoir when gravity w/cap off... Thanks
The cap should be vented, if air can't get in to replace the fluid leaving the reservoir the fluid can't get out.
So then all that air coming out is really locked in the system? Should I gravity bleed all the other wheels? I am only working on the furthest one first. When it stops, should I individually bleed (open/down/close/up etc.) each wheel with the cap off the remote reservoir? Thanks
It's a new plastic VW beetle-type reservoir, I would think it's vented but it stops draining when I tighten it. It looks vented...?
i'll tell you how i bleed brakes when i'm alone, i measure from my brake pedal up to my steering wheel and add one foot, then i cut myself a piece of 1"x2" wood board that length, then i take a couple good strong bungy cords and hook them to the steering wheel and around the back end of the wood so it's pressing on the brake pedal, it looks like a bow and arrow kinda, so i get in and pump up the pedal and then set my stick, go bleed a wheel, get back in and slide the stick off the pedal and pump up the brakes again, then reset the stick back on the pedal, i have a multi-vac, i built a pressure bleeder, i tried gravity bleeding but i always go back to this setup, works for me.
Good idea..right now there is no seat. I'm slowly seeing progress with the gravity bleed. Did rears, going on to fronts. Maybe not as quick because bleeders point up. I'm still open to suggestions. Checked out reservoir cap and the indentation is there for the center vent hole, but it didn' go all the way through...maybe the problem???
Maybe...But check the side of the cap. That might be the wall of a tunnel that goes off to one side. (if it was vented thru the top, the residual valve would squirt fluid out of the top)
Talked to my partsguy where I got the MC from, he said he'll just order another MC...sounds like that to him. I'mjust about frustrated-out!
pictures would really help, so if i understand your setup, you have a tube attached to the bleed screw and that tube is submereged in brake fluid in some kind of container? you remove the master cylinder cap and bubbles are coming out of your bleed tube which is submerged in brake fluid, do i understand correctly?
then if you havent already done so just wait for the bubbles to stop. leave the cap of the reservoir, that more bubbles are coming out with the cap off is a good thing, the vent in the cap only needs to be very small as the only time air needs to get in is when you have a leak in the system.
Did that, drained all four that way individually. Still no pedal. Went back and tried to then bleed each one the regular way using an ***istant pushing the pedal and couldn't get anything to bleed out.... ?????
so now with the cap off you open a bleed screw and fluid comes out? and you still have free play on the master push rod?
Lemme' see if I understand this: ***istant steps on pedal; you open bleeder at wheel w/ his hoof pushing down, and NO fluid comes out? You did install the rod between the pedal and master cyl., right? Just askin'. If the master is completely full of air, it may be tough to get enough air bled out of the system to get ANY pedal feel. But you 'bench bled' it. Should have something in there to get some kind of pedal going... you'd think. You're SURE there's no leak anywhere. COMPLETELY dry under the car; all 4 drums off (edit 4 wheel disks... no leaking cal's or hoses?) and no fluid in any? Been there - done that... Also, how fast are you guys pushing on the brake pedal? Brake fluid can foam up and get bubbles caught in it if a guy starts wailing on the pedal real fast. DAMHIK. When I bleed brakes, I use my old Snap on vacuum bleeder can, but don't even bother with vacuum (well, kinda' true - sometimes I'll vacuum a bit of fluid thru the system to start, but I shut the vacuum off and go manual so I can SEE that there's NO bubbles). I just use it as a ($200) catch can with several feet of clear plastic hose. I open the bleeder, stroke the pedal slowly, and make damn sure I don't run out of fluid in the reservoir. I generally work the pedal w/ my hand, so I can look under the car and watch the hose for air bubbles. When I'm not getting any more, that corner is done. This is how I bleed brakes after component replacement (I use the vacuum when I'm just topping off and pulling fluid thru a system for maintenance but haven't introduced any air). I can see very clearly when a corner is bled - there's no questions. Never had an issue doing it this way. If anything I've thrown out there seems like it's insulting, and that you're not that dumb... don't take offense. I'm just trying to put out any ideas/questions I can so that it'll help you find the solution. Best o' luck! -Bill
an easy way to bleed the brakes yourself is to get some vacuum check valves.. there cheaper then the 1 man bleeder screws at the store.. the brake fluid will ruin them but they will last long enough to bleed your brakes...
Took new MC back off. Finally noticed there is a difference between the pistons...MP brakes' piston is solid with a slight conical machined indent, '68 Vette MC has a 3/4" hole in the center. The booster pin is probably not even pushing the piston, just sliding inside it! The MPbrakes MC costs $120, the '68 Vette MC from the parts store cost $35...did MPbrakes purposefully not tell me the right info? Can I get a bigger pin so I don't have to drain/unplumb the remote reservoir etc? Reall tired of draining/removing MC. Thanks for everyones' help.
now were getting somewhere, a smart fellow on a lathe could make a plug to slide into your vette master making up the difference in depth, you have to make very sure the booster rod could never fall out and jam in any way, i wish you had a camera, these threads are so much more fun with pics.
Actually I found a guy who was selling the long pushrod for the '78 MC, I bought it but I haven't received it yet from Ebay. I also got a note from a hamber saying he uses a grade 8 bolt, cut to length and put in the piston. Waiting to solve this. Thanks for your concern.
Actually the whole problem stemmed from MP brakes giving me the wrong info on the MC. The model I needed is a '78 or newer, the '68 they told me to get does not work with the pushrod I have in my booster. Bought a '78 MC tonite...it sure looks right. I'm putting it in tomorrow.
OK...new MC, all is great! MP brakes didn't want to tell me what MC they had sold me...when they did they told me the wrong year. They wanted $119 for theirs...parts store cost $30. Even after buying 2 MC's, it only cost $60. Makes you wonder, doesn't it? Thanks to everyone for their help!
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