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Brake bleeding........help!

Discussion in 'The Hokey Ass Message Board' started by Rocket88, May 19, 2005.

  1. Rocket88
    Joined: Jul 11, 2001
    Posts: 911

    Rocket88
    Member

    I can't seem to get the brakes to bleed on dad's car.
    No matter what I do the brake peddle is still mush, it goes right to the floor and the car barely stops.
    The system is all new including the lines, except for the rear flex line and back.
    Here's the system, 7" booster and master under the floor, Wildwood adjustable proportioning valve, residual valves, disc brakes up front and a 57 Chev rear end.
    I've checked the system front to back for any leaks, fixed the couple that were there.
    Because the master is under the floor I'm using the push and bleed method instead of pumping the pedal.

    What the hell am I doing wrong? :confused:
     
  2. DIRTYT
    Joined: Oct 22, 2003
    Posts: 3,264

    DIRTYT
    Member
    from Warren,MI

    what about re bleeding the master. i know fathack had to re bleed his when he was trying to get his system in order and that was the problem on his
     
  3. I agree...My buddy had a supposedly rebuilt master cylinder and it was giving us all kinds of problems until we just replaced it. Once you've checked for leaks at all the lines and wheels...it could be there's just fluid getting pumped past the piston in the master.
     
  4. Do you know the bore size of the master cylinder? You may have a front drum type master.

    I would also use the master cylinder to push the fluid through the bleed screw.

    Did you bench bleed the master?
     

  5. theodore
    Joined: Nov 28, 2003
    Posts: 180

    theodore
    Member

    Maybe no residual valve?
    Try pressure bleeding it with an inner tube.
     
  6. oldspeed
    Joined: Sep 14, 2004
    Posts: 897

    oldspeed
    Member
    from Upstate NY

    Don't have the front calipers on backwards do you. make sure the bleeder is on top higher tha anything else. Had this happen to a friend that was going through the same thing you are his were switched left to right chnaged them and every thing was fine.
     
  7. oldcarfart
    Joined: Apr 12, 2005
    Posts: 1,437

    oldcarfart
    Member

    do you have a disc/drum master cylinder and is it plumbed correctly?
     
  8. Rocket88
    Joined: Jul 11, 2001
    Posts: 911

    Rocket88
    Member

    The master is part of a kit from Stainless brakes.
    Everything is plumbed correctly and the calipers are on the right way.
    Brake fluid streams out of the bleeders, but I just can't get the peddle to firm up.
    The only thing I didn't do was bench bleed the master.
    Should I pull it out and bench bleed it or can I do it in the car?
     
  9. visor
    Joined: Aug 11, 2002
    Posts: 513

    visor
    Member
    from Missouri

    Yeah, I would take it out to bench bleed it.
    Make sure you have adjusted up the rear drum brakes
    until they have a slight drag.
    And also you may have to adjust the ratio up a little on the
    master cylinder push rod.
    Then re-bleed, starting with the rears first and don't be concerned
    about pumping them up. And then have someone crack the bleeder.
    After you have done all four....bleed them again one more time.
    Its so much fun.
    -------------------------------------------------------
    vagabonds cc
    opossum benders
     
  10. "IF" you didn't bench bleed the master cylinder first, it'll take a WHILE to get the air out. But keep doing your push and bleed. Pumping just agitates the air bubbles instead of removing them. It's possible if you got some cheesedick disc conversion that the caliper brackets aren't square with the rotors. This makes the pads come into contact witht the rotors at an angle, giving a mushy pedal. Probably just air though. I had a half pedal in my Ranchero the other day. Got JUST a bubble out of each of 2 bleeders and the pedal's at the top now! Point: the tiniest amount of air gives the most drastic results.
     
  11. colorado51
    Joined: Feb 24, 2003
    Posts: 1,577

    colorado51
    Member

    Hmmm, almost sounds like the residual valves are not working right and maybe allowing fluid to drain back in to the master(?).

    Maybe try a (MityVac) vacuum pump too. Those things work really well for stubborn systems.
     
  12. WildWilly68
    Joined: Feb 1, 2002
    Posts: 1,724

    WildWilly68
    Member

    Ya gotta bleed the master. Make a couple "C" shaped lines from the ports on the master and bend them up until they go into the fluid reservoirs. Clamp the master in a vise (gently) and then using a dowl rod or the pedal rod push the piston in about 3/4" and let out slowly. Do this until you get no more bubbles from the lines and then reinstall it.
     
  13. Brad54
    Joined: Apr 15, 2004
    Posts: 6,015

    Brad54
    Member
    from Atl Ga

    I'm not trying to be a retard or a smart ass, but you do have the rear drums on when bleeding, don't you?
    I, um, know a guy who tried to bleed his brakes with the drums off once, and it doesn't work.

    -Brad
     
  14. TAKE YOUR MASTER OFF THE BOOSTER-To Make sure it has a fraction of an inch of clearance when the master is held against booster "push rod"............a little free play if you will.;)
    If it has 'PLENTY' of slack there- lengthen the short-"rod"- that goes between the two components-cause It's too loose-
    either of these situations will render a good brake setup barely functional..
     
  15. Common problems that cause difficulty in bleeding brake systems:

    Calipers on wrong, very easy to confuse them but the bleeders need to be on the very top of the caliper.--- CHECK

    Leaks in the fittings or improperly flared or cracked lines, Unless you have experience with your flaring tool you will go through a few before you have a flare that looks like the factory done one. Split adapters or inverted flare cones that are dammaged or too small to seal with the line give you fits. --- CHECK

    Pumping too fast and airating the fluid, Novice thing to do when your excited and in a hurry to get the car on the road. Take your time and push the pedal slowly, --- CHECK

    Bleeding procedure, There are nearly as many way as there are opinions. My best suggestion is a piece of clear vinyl hose that fits suggly over the bleeder head and a mason jar. Fill the mason jar 1/4 way with clean fluid, crack the bleeder and place the hose over the head. The other end of the hose needs to be submerged in the fluid at all times. Slowly depress the pedal and watch for bubbles. When the pedal is all the way down snug the bleeder and let your helper release the pedal. Do this several times on each wheel starting with the one farthest from your master cylinder. --- CHECK

    Master cylinder adjustment, Not many suppliers will set the power booster pushrod in between the booster and master cylinder. There needs to be a small ammount of free play there for the piston in the master cylinder to return all the way to the "refill ports". If the cylinder is not allowed to return all the way the fluid trying to fill the air gaps is restriced and will make things difficult if not impossible. --- CHECK

    Return spring on your pedal, Easy to forget but on below floor systems it is paramount that you have one. The weight of the pedal itself will "ride" the booster and cylinder causing the piston to not reach the refill port as described above. Secondary problem is that pre-mature brake wear will occur and performance will deminish because of heat generated by the pedal applying the brakes. --- CHECK

    All of the above taken care of and you still cannot bleed the system, pull the master cylinder from the car. Bench bleed the cylinder. IF you have no air being pumped from the master cylinder from bench bleeding, make a pair of plugs to block both brake line ports on the master cylinder. Depress the piston and it should be VERY firm. IF you can push the piston in farther than an 1/8" the master cylinder is garbage and needs to be replaced.


    Good luck!
     
  16. Rocket88
    Joined: Jul 11, 2001
    Posts: 911

    Rocket88
    Member

    Thanks for the tips and suggestions.

    ELp, I went through your check list.
    Calipers are ok.
    Lines are good, no leaks, took my time with all the flares.
    Pumping too fast...partially guilty, wasn't too agressive but am using DOT 5 fluid, it does seem to airate (sp) easily.
    The bleeding procedure was as you described clear line and all, although I used a Coke can instead of a mason jar.
    Free play at peddle, 3/16" , manufacturer says 1/2"
    Return spring on peddle, yes.

    Sounds like time to bench bleed.
     
  17. There was a post a day or two ago dealing with a funny feeling pedal. The problem seems to have been pedal ration issue.

    Just a quick check if your pedal travels four inches, then your pushrod should move 1" into the booster/master. 4:1 ratio. Total travel of the master cylinder should be at least 1 1/4" and some will travel up to 1 1/2". So give that an eyeball before you pull the cylinder.

    :cool:
     
  18. you have to bench bleed the master before you do anything else- you really don'thave to take it off to do it. just disconnect the lines and put the little hose plastic screws in the line holes and have somebody hold em while you puch the pedal a couple times


    then you need to rebleed the system since you disconnected the lines - good luck
     
  19. marq
    Joined: Aug 22, 2003
    Posts: 1,423

    marq
    Member

    just had the same problem on my mates consul(english ford)turns out that although the pedal was returning the spring inside the master was weak and not returning the seal therefore no brakes.Although the pedal was up before we started there was a leaky cylinder that needed doind but once we peplaced the cylinder the problem occured .We swapped out for a new master and hey presto brakes are back....................Marq
     
  20. skipperman
    Joined: Dec 24, 2002
    Posts: 1,837

    skipperman
    Member

    LISTEN to EL P ......... Also.. you can run down the problem sometimes by clamping off the rubber lines to the calipers and rear brakes...see if you have a pedal ... relase the rear first and check pedal ...then do the fronts ... that was MY post a couple days ago,,,and it WAS pedasl RATIO !!!! moved the clevis and I got a PEDAL !!! EL P suggested it .....

    Jersey Skip
     
  21. PS- I've had GREAT luck bleeding the closest wheel FIRST! I find that eliminating air soonest allows just fluid to be pushed to the next wheel, and the next. I know, it goes against what we've all been taught. BUT IT WORKS!!!!!!!!!
     
  22. Rocket88
    Joined: Jul 11, 2001
    Posts: 911

    Rocket88
    Member

    The pedal assembly is from TCI, the pedal ratio is pre-set with no adjustment.

    [​IMG]

    I'll be putting the car back on the blocks tonite.
    I'll try bench bleeding the master and see what happens.
     
  23. stickylifter
    Joined: Feb 21, 2005
    Posts: 1,268

    stickylifter
    Member
    from Detroit

    Check this: Are the tensioners on the read wheel cylinders all the way out?

    I was going nuts trying to get my brakes to work, turns out that I hadn't expanded the shoes all the way out, so the wheel cylinder was filling up, and the pedal was bottoming out, before the shoes made contact with the drum.
     
  24. gashog
    Joined: Dec 9, 2005
    Posts: 978

    gashog
    Member

    Make sure your master cylinder is solidly mounted. A mushy pedal is often a symptom of flexing at the MC support. This is particularly true with an entirely new installation.
     
  25. old beet
    Joined: Sep 25, 2002
    Posts: 5,750

    old beet
    Member

    I think he figered it out, that post is 2 1/2 years old..........OLDBEET
     
  26. gashog
    Joined: Dec 9, 2005
    Posts: 978

    gashog
    Member

    yeah, I sort of figured that, but since no one mentioned flexing as a possible cause of a mushy pedal, I thought I'd add it to the thread for completeness.
     

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