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Technical Poncho 54 uneven braking effect

Discussion in 'Traditional Customs' started by rigg0, Jun 11, 2017.

  1. rigg0
    Joined: Apr 13, 2013
    Posts: 17

    rigg0
    Member
    from Sweden

    Uneven braking in The rear (original drum brakes)
    2.5-3 on The left and 0.8 on The right.

    All looks good, brake shoes looks good. Wheel cylinder looks good, no leaks. The drum has A trace in it but is overall good.

    What should i do? Where to Begin?

    Hard to find parts to Pontiac 54s in sweden. Any other GM part fitting on my brakes?
     
  2. Wheel cylinder piston bind due to moisture absorbed in the brake fluid over time, rust in the cylinder bore.
     
  3. rigg0
    Joined: Apr 13, 2013
    Posts: 17

    rigg0
    Member
    from Sweden

    But when i brake The pins (link) goes out on both sides as it should?
     
  4. Have the brake shoes ever been oil or brake fluid soaked? If so, the contamination will never be able to be removed.
     

  5. rigg0
    Joined: Apr 13, 2013
    Posts: 17

    rigg0
    Member
    from Sweden

    Nope, it looks good.
     
  6. Kinked or internally rusted line. Back to wheel cylinders--rust inside the bore limiting piston movement, even though movement has been observed.
    Have to think about how many possibilities that the restriction is coming from, look at everything.
     
  7. squirrel
    Joined: Sep 23, 2004
    Posts: 46,718

    squirrel
    Member

    my old Hollanders interchange manual says Pontiac brakes only, 49-54 are mostly the same.

    So you won't find much else to get parts from, unfortunately.

    If all the parts you can see look identical on both sides, then it is probably something you can't see. As suggested, the wheel cylinders or lines could be corroded or plugged or something. Wheel cylinders are available for a reasonable price from places like rockauto.com, I don't know if they ship international.
     
  8. Is there more than 1 bore size ?
     
  9. rigg0
    Joined: Apr 13, 2013
    Posts: 17

    rigg0
    Member
    from Sweden

    Should check The brakefluidline for air.
    Take down The wheelcylinder and dissect it?
    Was Hoping i wasnt going to need to buy new gear since i would not have it in time... But new wheel cylinder and shoes May just Solve The problem, just don't in time.
     
  10. rigg0
    Joined: Apr 13, 2013
    Posts: 17

    rigg0
    Member
    from Sweden

    Just as i feared.. Well will check that store for parts, like i said. Ponchos 54 and earlier is Hard to find parts over here.
     
  11. Belair1964
    Joined: Aug 19, 2015
    Posts: 31

    Belair1964
    Member
    from Illinois

    If you are watching the shoes move without the drum on there is still a possibility of air or moisture in the system. That may not show up until there is actual pressure in the lines with the shoes contacting the drum. Are the drums within spec ? The rears are the furthes from the master so maybe a good thourough flush and bleed will help out.
     
  12. rigg0
    Joined: Apr 13, 2013
    Posts: 17

    rigg0
    Member
    from Sweden

    Going to bleed The system in the Middle of The week. Fingers crossed
     
  13. Truck64
    Joined: Oct 18, 2015
    Posts: 4,124

    Truck64
    Member
    from Ioway

    Each wheel on axle must be singing from the same page. So any and all repairs and maintenance must be performed in axle pairs. Drums should be same diameter.

    Rubber brake hoses are notorious for this, sticking wheel cylinders, weak return springs, worn backing plate shoe pads.. Then, even with serviceable components installed they need to be adjusted correctly. Start from that point where everything is adjusted as tight as can be adjusted, and back away from there. Adjustment attempts from the other direction will leave too much "slop" or clearance in the brakes.
     
  14. cb186
    Joined: Jul 5, 2013
    Posts: 262

    cb186
    Member

    Are the rubber lines old or new? If old, replace them and see if it evens out the braking. The hoses can collaps inside, preventing pressure from getting through. Inverse, if you get on the brakes really hard it can force fluid through and then trap it on the cylinder side causing the brake on that side to drag until the pressure bleeds back throught the hose restriction.

    I found this out the hard way on a daily driver.
     
  15. Rusty Heaps
    Joined: May 19, 2011
    Posts: 607

    Rusty Heaps
    Member

    just dealt with same on an OT vehicle
     
  16. rigg0
    Joined: Apr 13, 2013
    Posts: 17

    rigg0
    Member
    from Sweden

    Bleed out The bad side then i skrew/turned them soo They both took likewise on both sides, they Where very uneven at first. Made them equal then turned The good side looser and The bad side tighter. From 3 left 0.8 right to 1.7 left 2.0 right, it passed. ( max diff in sweden 0.3)
     
    gimpyshotrods likes this.

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