Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Need to stop.

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by A&P, Feb 28, 2002.

  1. A&P

    A&P Registered Member

    Joined:
    Dec 3, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    San Antonio, Texas
    I'm having problems with my rear brakes. One day, all six of my lug posts in the pass. rear corner tire of my truck decided to jump from my truck while traveling at 45 mph. Then consequencially the tire did too. I got towed home on a flatbed, and shortly thereafter replaced my brake shoes and all brake hardware in the drums. (because of damage from the tire falling off.) Anyways after doing this to both sides, my rear brakes ceased to work. I figured the master cylinder went on me, so I replaced it. (BTW after any maintenance on my brakes, I do a good bleed on the whole system.) Replacing the cylinder didn't help. My E-Brake works fine and the brake fluid resivoir is full. Does anyone have any suggestions? It would be much appreciated.

    When All Else Fails, Check The Blinker Fluid!
    (Original Author, Sorry Sparky)
     
  2. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

    Joined:
    Apr 21, 2001
    Posts:
    5,634
    Likes Received:
    0
    Location:
    Escondido, CA
    try having your brakes power bled. call around for prices. i had this done on my chevelle after i redid the whole system. it was just easier for me at the time when i made lots of money. it worked gread. cost me 75 bucks
    Grant

    take me drunk, i am home
    www.geocities.com/seventy4blazer/parts4sale.html
     
  3. A&P

    A&P Registered Member

    Joined:
    Dec 3, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    San Antonio, Texas
    I suppose I could do that but.....
    1. Don't even have $75
    2. My bleeding techniques have always worked perfectly before.
    Something else bugs me. My pedal sinks 3/4 of the way to the floor with almost no resistance and my brake light comes on as a indication from the proportioning valve that somethings going haywire. I don't know, maybe I need to swap that out too. Thanks tho.

    When All Else Fails, Check The Blinker Fluid!
    (Original Author, Sorry Sparky)
     
  4. donimator

    donimator 1/2 ton status

    Joined:
    Jun 11, 2001
    Posts:
    444
    Likes Received:
    0
    Location:
    Tacoma WA
    Try adjusting out your rear brakes.


    73 3/4 ton Chevy. 383 stroker, TH350, NP 205, 14bolt FF(Detroit), Dana 60 (open),6in. lift, 36x 14.5 super swampers
     
  5. A&P

    A&P Registered Member

    Joined:
    Dec 3, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    San Antonio, Texas
    My rears are adjusted to the hilt. I can't hardly get the damn drums on with the way that they are. Everything is done correctly in the drums also. I even double checked with chilton's manual. It's perfect except for the fact that it doesn't work.

    When All Else Fails, Check The Blinker Fluid!
    (Original Author, Sorry Sparky)
     
  6. Rob 85K5

    Rob 85K5 1/2 ton status GMOTM Winner

    Joined:
    Feb 17, 2000
    Posts:
    1,487
    Likes Received:
    0
    Location:
    Pensacola, Florida
    I think you may have already found the problem, Proportioning valve! If you ar not leaking fluid anywhere and the brakes are set up correctly, maybe the shock to the valve when the tire fell off and mashing the pedal over and over screwed it up. That would be my next item to attack.

    Rob

    <font color=orange>Bleedin' Chevy Orange</font color=orange>
     
  7. Overkill

    Overkill 1/2 ton status

    Joined:
    Jan 15, 2002
    Posts:
    284
    Likes Received:
    0
    Location:
    Orlando, Florida
    I thought I read somewhere, maybe for a different truck, that when a major fluid pressure inbalance in the rear was detected it would lock the proportioning valve to the back brakes. I guess so if you lose a wheel cylinder you will still be able to stop with the front, or something like that. Im not real sure what Im talking about, but thought I would throw it out there in case someone else might have researched it, but forgot about it. Anything is a possibility. I think there was a button or something that had to be pressed to reset it. (?).

    Pics at <a target="_blank" href=http://community.webshots.com/user/jlblmkh>http://community.webshots.com/user/jlblmkh</a>

    (Formerly heaj1)
    Swimmin like a rock, slingin like a stock, but not for long.
     
  8. A&P

    A&P Registered Member

    Joined:
    Dec 3, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    San Antonio, Texas
    Thanks a lot guys. I'll check into all of this, but I think I'll end up having to replace the proportioning valve. Your help is much appreciated.

    When All Else Fails, Check The Blinker Fluid!
    (Original Author, Sorry Sparky)
     
  9. RESTORE89

    RESTORE89 1/2 ton status

    Joined:
    Jan 31, 2001
    Posts:
    548
    Likes Received:
    0
    Location:
    CHAS SC
    did you replace the rear wheel cylinders?
    and did they bleed out OK?
    the prop valve "almost" never goes bad, i would look at every thing else first.
    if the rear cylinder is faulty it will cause the imbalance and the prop valve will do its thing and make the light come on and the pedal go funky.
    also did you do both sides or just the damaged side?
    keep us posted
    chris

    It needs a bigger motor.
    what's in it now?
    doen't matter it NEEDS A BIGGER MOTOR
    89 350tbi/700r4h/np208/4.11's
     
  10. Overkill

    Overkill 1/2 ton status

    Joined:
    Jan 15, 2002
    Posts:
    284
    Likes Received:
    0
    Location:
    Orlando, Florida
    One more thing that I heard was, when you haven't serviced the brake system for a very long time and you try to bleed to system, the master cylinder sometimes gets crud built up on the piston and when you get the braqke pedal to go alot further than it has in a long long time that crud can chunk off and screw up seals and such. Again, just a thought.

    Pics at <a target="_blank" href=http://community.webshots.com/user/jlblmkh>http://community.webshots.com/user/jlblmkh</a>

    (Formerly heaj1)
    Swimmin like a rock, slingin like a stock, but not for long.
     
  11. RESTORE89

    RESTORE89 1/2 ton status

    Joined:
    Jan 31, 2001
    Posts:
    548
    Likes Received:
    0
    Location:
    CHAS SC
    yeah, but i think he said he replaced the master cylinder, or are you saying the crude would get into the rest of the system.
    chris

    It needs a bigger motor.
    what's in it now?
    doen't matter it NEEDS A BIGGER MOTOR
    89 350tbi/700r4h/np208/4.11's
     
  12. A&P

    A&P Registered Member

    Joined:
    Dec 3, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    San Antonio, Texas
    I did replace the cylinder and yes it is very possible that there is crud in the lines. I'm just wondering why the pedal sinks 3/4 of the way in before anything engages. BTW, it's only the fronts that engage. Every time I pull the drums, there's no indication that they've been contacted by the shoes. No dust, or anything. All dry and clean. If there was crud, or a blockage, wouldn't I have some resistance in the first 3/4 stroke? Ahh well, just need time and money to fix this one. Too bad I have neither. Thanks for the suggestions guys.
    -Ben

    When All Else Fails, Check The Blinker Fluid!
    (Original Author, Sorry Sparky)
     
  13. Overkill

    Overkill 1/2 ton status

    Joined:
    Jan 15, 2002
    Posts:
    284
    Likes Received:
    0
    Location:
    Orlando, Florida
    Sorry about that, I didn't catch the part where you replaced the master, my bad. Have you tried to adjust the linkage from your brake pedal to the booster? I think it can be adjusted, just undo the clip and twist the shaft, kind of like a tie rod. I just replaced my vacuum booster for the brakes and mine needed to be adjusted, Again, just a thought. I don't see where crud in the line would cause the brakes to go 3/4 of the way down before engaging, I was referring to the master cylinder. Also might want to double check and see if there is an adjustment between the booster and master (not sure if there is or not). When the brake pedal gets to the 3/4 point, do they grab solid or are they still a little "mushy"? If they grab solid and are stable I would guess it's a linkage thing. If they are still mushy I would suspect air still in the lines? Hope this helps, and If I am not correct about anything here, someone please correct me. Good luck. You might be able to get away with pulling a drum off and have someone you trust push the pedal, gently and very very slowly, to see if the rear cylinders are moving at all. Just be very carefull or you wil be replacing them again, if they get pushed too far out, since there is no drum to stop them from over-extending. Maybe you can actually see if there is something not lined up right. I know I had a hell of a time getting mine aligned back up, due to years of rust and caked/baked and dried up mud in em. Some of those springs just don't want to play nice, hehe.

    Pics at <a target="_blank" href=http://community.webshots.com/user/jlblmkh>http://community.webshots.com/user/jlblmkh</a>

    (Formerly heaj1)
    Swimmin like a rock, slingin like a stock, but not for long.
     
  14. Sparky

    Sparky 1/2 ton status

    Joined:
    Aug 20, 2000
    Posts:
    423
    Likes Received:
    0
    Location:
    San Antonio(summer) Texas A and M (school year)
    Sounds like you need to curse at your truck some more to me. That, or let me work on it so it gets done right &lt;img src="http://coloradok5.com/forums/images/icons/wink.gif"&gt;. I'll take a look at it with you if you dont get it done in the next week. Going to have all of spring break starting the 9th. Oh, and my parents are out of town so we have my whole garage to ourselves.


    Wait a seconde, why do you need back brakes anyways. You and I both know that stoping is overrated!!!



    When all else fails... Check the blinker fluid.
    78 K-5
    <P ID="edit"><FONT class="small">Edited by Sparky on 03/01/02 08:36 AM.</FONT></P>
     
  15. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    The proportioning valve has a button on the end of it. Try pushing that button and then bleed the brakes. Might have to hold it to bleed the brakes. I think that's the release button for when the system has lost pressure.

    Women dig dents and flat paint!
    coloradok5.com/gallery/Grim
    75 Jimmy, Dollar
    Grim-Reaper
     
  16. A&P

    A&P Registered Member

    Joined:
    Dec 3, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    San Antonio, Texas
    Once again, Thanks guys. And Sparky, how did marks jeep fare? Did you guys recover it? We need to do another slab run.
    -Ben

    When All Else Fails, Check The Blinker Fluid!
    (Original Author, Sorry Sparky)
     

Share This Page