Rear Drum Brake Bleeding issue

Discussion in 'The whoa and the sway.' started by Rich Skylark, Jun 19, 2019.

  1. Rich Skylark

    Rich Skylark Gold Level Contributor

    I recently changed my 2 front brake hoses for safety reasons (25+ yrs old ). My 68 SkylarkCustom350 has manual drums all around with no issues. I bled the fronts using a friends power bleeder and it did the job nicely. Having the power bleeder and in recent memory not having bled the rears in a long time figured why not do the job correctly & get rid of the nasty fluid in the rears. Surprisingly the rear bleeders didn’t put up fight, opened the master and hooked up the machine to the passenger rear screw. It sucked fluid for 30 seconds then nothing. Ditto the other side. The car was jacked up in the rear for access. I thought maybe the master being lower than the bleeders might be the problem and raised the front higher good. Put car back on ground & pedal is spongy . Opened master lid tapped brakes lightly the front reservoir is gurgling, back reservoir nothing. Prior to this brakes were normal - any & all thoughts welcomed .
  2. 70skylark350

    70skylark350 Well-Known Member

    I went trough this same thing buddy, drove me nuts. when you bleed the one wheel you are actually sucking the oil out of the other wheel, it will drive you nuts.
    get the one wheel bled, then have somebody in the car an start applying brake pressure as you open the other bleeder to force oil to the evacuated side.
    Those power bleeders actually screw you on the rear.....
  3. 70skylark350

    70skylark350 Well-Known Member

  4. Rich Skylark

    Rich Skylark Gold Level Contributor

    Thanks Dave for the info; when you are at work and you keep thinking of what you missed to the point of distraction it’s time to pick anybody’s brain whose willing. At this point going to try bleeding at the rear wheel one more time then try at the I’m leaning toward a new master ( it’s a bendix unit ) Just to be sure the master cylinder should be level, higher, or lower than the rear wheels when bleeding? Thanks in advance !
  5. bostoncat68

    bostoncat68 Platinum Level Contributor

    I doubt you need a master. I might look to be sure the rear hose is not collapsed? Is it 25 years old too?
    DasRottweiler likes this.
  6. Smartin

    Smartin Staff Member

    Replace rear hose and it wouldn't hurt to replace rear wheel cylinders either.

    Also make sure pedal is all the way up. If it is partially depressed, it may hinder the flow through the MC.

    Last year, I bought a pressure bleeder that pushes the fluid TO the wheels. I used to use a mity vac, but couldn't ever get great results with it. The pressure bleeder is light years better.
  7. scubasteve455

    scubasteve455 Well-Known Member

    We all have been there. Sucks
  8. Rich Skylark

    Rich Skylark Gold Level Contributor

    Took a few days away from Buick to research my brake bleeding issues. Thanks for the input I received .Going to look at the rear hoses carefully ( probably should be changed anyway) They look at least 25 yrs old and while I don’t see any fluid leaks from the hoses, lines, or wheel cylinders, changing these parts will give me peace of mind that these components are new. Will update after a “ looksee” in the rear.
  9. OZGS455

    OZGS455 Oh what a wonderful day!

    yeah hoses dont have to leak to fail.
    They tend to close up internally with age.
    Personally I gravity bleed to avoid any pedal pumping and its easy one man operation
    Jusy remove the master cyl cap make sure the master is higher that the bleeder and then just open the bleeder half a turn and let it drip onto a shop rag.
    If theres no initial flow just a couple if hand taps on the pedal will get it happening.
    then keep an eye on the master so it dont completely empty.
    When you get clean fluid dripping out the bleeder tighten it and go to the next and repeat.
    Takes longer than other methods but thats cool.
    Brake fluid is hydroscopic in that it absorbs water, its best to change fluid every 2 years to keep brake fluid at its optimum.
    Our older cars use dot 3 fluid.
  10. buick64203

    buick64203 Just plum crazy Staff Member

    If you need a new rear hose, let me know Rich. I keep them in stock.

    Like I said, have someone pump up the pedal and crack the steel line going into the rear flex hose. If you have pressure before the flex hose and no pressure after the flex hose, you know the answer.

    If there is no pressure going into the flex hose, try bleeding it at the master itself. Pump up the pedal and bleed it right at the line coming out of the master and see if you have pressure there. My bet is the rear flex line. No one replaces those. I'd bet it's original to the car
  11. Rich Skylark

    Rich Skylark Gold Level Contributor

    I am going to do your suggestions tonight, just have to to procure an assistant ( willing or unwilling ). I have to get the brake issue resolved by Saturday, along with installing my one wire alternator, as my Buick has to leave the garage for the day on Saturday due to a family party at the house- preferably under its own power. I will pm you later w/ what I come up with. Thankfully a rare day off tomorrow to hopefully put this to bed.
  12. Rich Skylark

    Rich Skylark Gold Level Contributor

    A follow up on the rear
    Brake bleeding problems I was having. When I was
    Checking the rear brake system over for leaks a final time , I took a better look at the rear brake hose that is connected to the rear lines . The square brass end was loose! Maybe 2’turns at most and it was off. I’ve never touched this part in the past 5 years I’ve owned the car. I snugged it down, bled brakes in the usual manner and I am finally getting a pedal. Go figure ?!
  13. Bygblok

    Bygblok Well-Known Member

    I had no rear brakes at all until I changed the hose. I was getting some fluid to the wheels but not enough to work the brakes. When I changed the hose I tried my vacuum bleeder and it wouldn’t do a thing. Had my wife come out to the shop and pump the brakes to bleed them and everything was happy again.....especially me since I now have rears again!

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