Close



Results 1 to 13 of 13
  1. #1

    Default 1980 Cobra Drum Brakes - Rear Passenger wheel getting very hot

    This one has me a bit baffled.

    I just redid the brake shoes on the kids car and now the rear passenger wheel is getting very hot (driver side is fine) The drums don't seem to be adjusted too tight and everything seems to be put together correctly. I double checked and even re-bled the lines.

    I suspected the e-brake sticking but it engages and releases OK and the drums slide off no problem after working the brake etc. Its almost as if the brakes are not releasing properly when driving. Cables were replaced a couple years ago.

    Anyone have any ideas or ran into something like this before ?

    Thanks in advance.

  2. #2

    Default

    My guess would be the wheel cylinder having some dirt in it which doesn't always let all pressure release and therefore making it drag.
    How does the brake fluid look like when bleeding?


    Verstuurd vanaf mijn SM-A300FU met Tapatalk

  3. #3

    Default

    The fluid is super clean and comes good. I actually swapped wheel cylinders with some others I had and same result.

    I am going to disassemble again and try to lube up the e-brake cables today as I still think one of them may not be retracting enough.

    Researching a few things I have read different points of view on the internet about primary and secondary shoes. It seems consensus is the shoe with the smaller surface goes toward the front of the vehicle along with the white (heavier) return spring ?

  4. #4

    Default

    As for what I think primary shoe goes in front and is the smallest of both.But have you crosschecked with the other side brake for the return spring positioning? I will try to have a look in my haynes tomorrow to look for a picture. Or maybe you'll find one online.

    Verstuurd vanaf mijn SM-A300FU met Tapatalk

  5. #5
    FEP Super Member
    Join Date
    May 2003
    Location
    Roseburg Oregon
    Posts
    3,308

    Default

    Are the friction points on the backing plate smooth and properly lubricated .
    Do the simple things first .
    clowns to the left of me , Jokers to the right

  6. #6

    Default

    Yep the backing plate pads are smooth and I lubed them up. When assembled I can slide the assembly side to side easily so pretty sure its not binding. White spring to front and green spring to back seems to fit the best so thinking this is the correct way. From what I can see the shoes are symmetrical so could be installed front/rear.

    I found the brake cable on passenger side not retracting very well...so completely disconnected it for a short trip to see and still the same heating problem...so I'm still ??? at this point.

  7. #7

    Default

    I went through a long, long troubleshooting ordeal with drums looking on - tried everything and it finally turned out to be the master cylinder not allowing brake pressure to be released.
    I know, since your problem is one side only, the master cylinder doesn't make sense. (But if you've tried everything else...)

    Back the adjuster wheel off a couple clicks and take it for a drive.

    What kind of car is it ? (nevermind, it's in the title)
    Last edited by jessesandy; 07-02-2017 at 08:36 PM.

  8. #8
    FEP Super Member erratic50's Avatar
    Join Date
    Dec 2016
    Location
    Nebraska
    Posts
    4,575

    Default

    It sounds to me like the rear drum brakes are just begging to be replaced with disc.

    I ran drums for 24 years on my 86. I've replaced the shoes countless times, wheel cyl rarely but at least once.... I've had debris in the lines cause this type of problem.

    A bad piece of rubber on the master cyl lid is what kicked off my problems. I started by just adding a new lid and blew out all the fluid. Should have back-blown it from brake to master cyl. My debris went further and caused more issues as it worked its way through the proporting valve and lines and wheel cyl.

    For me I've went rounds with proportioning valves a time or two also.

    In all the years and miles I also had to inspect then replace the rubber hose on the rear diff to body line.

    Direct to your ordeal - If you have debris or line damage on the side getting hot after the it's after the T on the diff it is a likely culprit.

    This all being said it's chasing a broken TV when the building is on fire. Modern cars stop SO fast and it's a bit of a gamble driving a four eyed fox surrounded by them. Here in Nebraska the interstate speed limit is 75 and I'm SO thankful that I upgraded my brakes - I would be dead if I had waited to do it.

  9. #9

    Default

    I'm not sure if 85 drums
    are the same as 80 but I just did mine and here's a pic
    Attached Images Attached Images  

  10. #10

    Default

    Thanks for the input....after about 12 hours of messing around and several hot wheels later I am making some progress. I eliminated the e-brake issues as it didn't seem to matter either way cable or no cable...although I was able to free up the passenger cable better with some lube.

    The new shoes just don't seem to wanna work...maybe they would wear in but not before they cook the wheel !! The drums would boil spit after a short 15 minute drive. Funny though cause all holes are identical to the old shoes and from what i can tell are the same exact shoe except slightly more lining etc...and they fit the hub nicely too.

    The last thing I tried was putting the old shoes back on the passenger side and wouldn't you know the heating issue was gone. So the latest test drive I hooked up the ebrake again with the old shoes and tightened adjuster so the drums were fairly tight and...cool wheel when I got home...WOOHOO !!

    As for the spring question and after messing around and having them both ways I don't believe switching them makes much of a difference. Your pic is opposite to what I have currently have. Maybe someone else knows the reasoning or if it matters etc.

    Going for another rip to give it a good test...hopefully its solved.

    Cheers

  11. #11
    FEP Senior Member
    Join Date
    Mar 2008
    Location
    darien il
    Posts
    523

    Default

    measure the thickness of the braking material on the shoe. it sounds like the shoe is for a cut drum which could handle thicker lining.

  12. #12
    FEP Super Member gr79's Avatar
    Join Date
    Jun 2009
    Location
    SE Michigan
    Posts
    5,141

    Default

    If not smooth, good idea to have the drum cut if not done already.
    Or a new one. Inexpensive.
    Could always try backing the adjuster so the new shoes are off the drum.
    Then let it self adjust to what it needs. You know, back up and stop multiple times so it can do its thing.
    Of course, the adjuster screw should work freely. A little wb grease on the threads works fine.

    Had a problem with my Ranger drum brake once.
    Has same 9" shoes as the Mustang's.
    Replacement spreader bar was for a 10" brake.
    Eventually failed, came off, and took out most everything in there, including the wheel cyl.

    9 and 10 parts look alike. 9" interchange number is 474, 10" 151.
    The 9" truck or later Mustang version #569 also works. 10" truck is 581
    Rock Auto lists specs avail both 1.75 and 1.81 widths.

    I don't do drums anymore. Done it many times but a shop is better at it.

  13. #13

    Default

    Yeah...put on lots more miles and the wheel/braking has been good ever since going back to the old shoes on pass side. I gets slightly warm and same as the other wheels so I know its working.

    Only thing I can think of is I bought the heavy duty riveted shoes...so maybe they have a slightly different shape on the lining and rub on the ends..not sure? I placed them in the drum on the floor an it looked like they fit in the arc nicely. Adjuster wheels were lubed and working nicely too. Good point about possibility of mixed and matched parts with a 10" system etc. It was definitely wearing into the lining as there was already dust (along with the hot drum) after the short test drives. Maybe they would have worn in even but like I say can't see it not cooking the wheel cylinder or axle seal first. You could feel the wheel starting to bind when taking off or at lower speeds.

    Funny the driver side had no issues and still has the new shoes. I measured the drums with a caliper (which are really smooth BTW) and they were within 5mm of the stamped allowable on the outside. Oh well, the upside is I am all educated up on drum brakes and getting real good at removing and installing the hardware and stuff...haha !!

    For now its working good so I'm not going to mess with it...

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •