Strange Brake Issues

Discussion in 'Ranchero Tech Help' started by Mike1969, Aug 16, 2015.

  1. Mike1969

    Mike1969 In Fourth Gear

    Messages:
    313
    Location:
    Missouri
    It was a little pricey to rebuild/replace everything, but looking back, I'm glad that I did. Brakes aren't something to cut corners on, in my opinion. It's not only my safety, but other people's on the road as well. Now I have peace of mind and confidence in my braking system! :)

    Doubling down on that assessment of O'Reilly's parts sometimes being junk Davis. Can't say that I've been impressed with much of anything I've gotten from them.
     
  2. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    I am experiencing a similar problem with my LF break. I also replaced both calipers and pads, rear break cylinders, all flex lines, master break cylinder, proportioning valve from Willwood and the hard line from the prop valve to the rear distribution block. I did not yet replace the hard lines on the front and the rear but as this fixed your problem I still have hope it will fix my issues as well!
     
  3. crab1

    crab1 In Second Gear

    Messages:
    40
    I lucked out and found a complete front disk setup from a 70 chero including prop valve, works like a charm after making a couple new lines.
     
  4. crab1

    crab1 In Second Gear

    Messages:
    40
    I lucked out and found a complete front disk setup from a 70 chero including prop valve, works like a charm after making a couple new lines.
     
  5. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    Yesterday I installed new hard lines for the front. Was not lucky! The FL still locks. If I free up the pads the rotor is spinning. After stepping on the brake pedal the FL caliper remains tight.
    I bought the car a few weeks ago and had this issue from the beginning.
    The piston boot of the old caliper was damaged.
    I bought new calipers from Autozone and hoped this will do the trick.

    This is my first experience with classic cars. Should the caliper “float“ when you release the breaks or is it just the piston that “moves“ ?

    Would it make sense to replace the caliper bracket?
    We have two 73 or younger T-Birds sitting on a junkyard close to my house. Would the bracket fit?

    I am quite anxious to finally get her on the road!
     
  6. beerbelly

    beerbelly In Maximum Overdrive SILVER MEMBER

    Messages:
    3,478
    Location:
    Portland OR
    I suspect the damaged boot caused the piston to stick in the caliper due to corrosion. It's happened to me, and is a dangerous condition. Depending on what type of caliper you have, it may or may not be a sliding caliper; my factory style Kelsey Hayes 4 piston calipers are not the sliding type.
     
  7. Hillbilly

    Hillbilly In Maximum Overdrive

    Messages:
    6,249
    Location:
    Winchester, TN.
    Inside the caliper you will find a square cut "O" ring sealing the piston to the caliper. The square cut is there for a reason. As you press on the brake, fluid pushes the piston out of the caliper bore and deforms the square ring. When you release the pressure the square ring returns to it's natural shape pulling the piston back slightly letting the rotor turn freely. I suggest an experiment = Push the brake hard then instead of prying the pads away from the rotor, crack open the bleed screw on that caliper. If you get a squirt of fluid from the bleeder and the rotor frees up, you likely have a bad brake hose on that side. It is a common problem as the hoses age they come apart internally and the flaking rubber strands inside the hose form one way valves that cause exactly the problem you describe.
     
    1965 Ranchero 66G likes this.
  8. pmrphil

    pmrphil In Maximum Overdrive GOLD MEMBER

    Messages:
    1,457
    Location:
    central CT
    If yours is the sliding style of caliper it is important to clean and grease the slides or binding will occur.
     
  9. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    I will give it a try but I already replaced the brake hoses at the same time I replaced the brake calipers (about 3 weeks ago).
     
  10. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    Ok. That might be another try. I just hammered this sliding bracket and the “spring” on top between the lower part of the caliper and the caliper bracket without any grease. I cleaned it at least before

    I have some “all purpose” grease in my garage. Can I use that or would you recommend some special grease?
     
  11. Hillbilly

    Hillbilly In Maximum Overdrive

    Messages:
    6,249
    Location:
    Winchester, TN.
    There is a heat resistant grease for that purpose. Lightly grease the wedge, spring on top of the wedge and the caliper bracket where the wedge sits. Also add a little grease to the notch at the top of the caliper bracket so that end of the caliper can slide. Wondering about your wheel bearing adjustment. There has to be a tiny bit of play in the final bearing adjustment to allow the rotor to barely wiggle to push the pads away from the rotor. This works along with the square cut "O" ring to keep the pads from dragging. Recomended final bearing tightening is only finger tight, not cranked down to zero play.
     
  12. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    I did perform the experiment - unfortunately without success. There was some brake fluid coming out of the bleeder valve but the caliper did not free up. Here a short video that I uploaded to Youtube:
     
  13. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    @pmrphil

    I did clean remove the caliper, cleaned it on all surfaces where the caliper and the bracket could touch each other, and greased it with some caliper grease:

    [​IMG]

    Still not working :(

    Here is a short video (free rotor, locked rotor after stepping on the brake pedal and freeing up again):



    I will check the wheel bearing. Thanks for that additional tip. I thought it might be ok as the rotor is moving ok in my opinion.
     
  14. Hillbilly

    Hillbilly In Maximum Overdrive

    Messages:
    6,249
    Location:
    Winchester, TN.
    If greasing the slide points and checking the wheel bearing adjustment don't pan out, not much is left on the table to investigate. Hose passed the test. It is possible to get a bum rebuilt caliper. I have seen rebuilts that had the "O" ring twisted during assembly and others that were not cleaned properly before being rebuilt. Have also seen caliper pistons reused that had the plating peeling causing them to hang in the caliper bore. DANG !
     
  15. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    Alright...
    Back from Autozone with a new bearing.
    Installed with your recommended "torque" and new grease everywhere. The rotor is spinning better than before (without caliper mounted).

    Stepped on the break. Almost the same result. I have at least the feeling I do not have to use the same amount of force to spin the rotor but in my opinion, the rotor should spin free or at least by twisting it with my hand and not with a tool?

    The last option might be: get this caliper replaced by another new caliper...
     
  16. Hillbilly

    Hillbilly In Maximum Overdrive

    Messages:
    6,249
    Location:
    Winchester, TN.
    I assume the other side releases properly and you can spin the rotor by just your hand. If this is true then we have run out of options other than the caliper is faulty. It does happen. You have to remember that man made those calipers and man can screw up once in a while too. 9 out of 10 rebuilts work great but a bad one can pop up no matter if it is for a Ranchero or a year old Maserati.
     
    polarfuchs likes this.
  17. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    I installed another new caliper and IT WORKS!!!!

    Thanks for your awesome support guys!!!!
     
    pmrphil and beerbelly like this.
  18. beerbelly

    beerbelly In Maximum Overdrive SILVER MEMBER

    Messages:
    3,478
    Location:
    Portland OR
    Did all your parts come from Autozone? If so, it sounds like a shop to avoid.
     
    pmrphil likes this.
  19. polarfuchs

    polarfuchs In First Gear

    Messages:
    15
    Location:
    Tucson
    Most of the parts came from Autozone but it was only the FL brake caliper that was faulty.
    I am quite happy with the other parts so far so for the moment I won’t avoid Autozone yet I am also happy with their service in our local shop.
     
  20. crab1

    crab1 In Second Gear

    Messages:
    40
    The calipers I got from orileys we're so loose on the brackets front to back I rebuilt the originals.
     

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