Brakes binding

Home Forums MGTD Kit Cars VW Based Kits Brakes binding

Viewing 9 posts - 1 through 9 (of 9 total)
  • Author
    Posts
  • #234397
    Marc Lipsius
    Participant

    @mrlmd

    I went for a ride the other day and when I was done, I just happened to feel my wheels and hubs and noticed the right rear one was rather warm, so I thought the right rear brake was binding and needed adjustment.
    I had previously adjusted (loosened) my front left one maybe 6-8 months ago because the wheel was hot after a ride and the car seemed to steer a little to the left when you let go of the wheel, and that one was too tight. I loosened it (turning both star nuts equally) until the wheel would spin with just the slightest noise from the brake grabbing.
    When I had my engine rebuilt a year ago I had all new brake drum pads replaced, but apparently they weren’t adjusted correctly.
    I just jacked up the car and with stands underneath I loosened both star nuts on each of the rear wheels. turning the nuts at least a revolution or 1 1/2 revs and now the wheels are able to be spun with less force but will only rotate a half revolution after giving them a good forceful spin and you can still hear the scraping from the brakes. My question is, how far can you turn these nuts, what is a reasonable amount of adjustment? Both of my front wheels will spin many revs at a fairly good speed ’till they stop. The rear ones are still too tight. Do I keep adjusting these nuts until they spin free with just the slightest brake drum grab or is this OK?
    My emergency brake when set will drag on the wheels but won’t lock them tight against me rotating the wheels and I can’t see any cables going to them. Where do they connect to the rear brakes?

    #252961
    Royal
    Participant

    @royal

    First let me start with the usual disclaimer,  OK, now that’s out of the way.  I am somewhat afraid of the brakes on our vehicles.  They weren’t really the best when they were new and now, well…? There is always the possibility of a major hydraulic line failure and it would, of course, fail when you were hard on the pedal because you wanted to stop.   The “emergency brake” on the VW is a mechanical device which when you pull up on the handle, pulls on two cables which go to the rear shoes, spreading them apart.  You should be able to lock the rear drums with the emergency brake handle.  

    Yes, it is normal that the rear drums will not spin as freely as the fronts since the rears are also spinning the axles and are slowed by the oil in the transmission.  I really don’t think that there is a “reasonable amount of adjustment” for the brakes.  If you took the brake drums off you could then measure the thickness of the brake shoes and there is a minimum spec for that (but I forget what it is).  
    It should be easy to see where the emergency cable enters the backside of the brakes.  It’s at the very bottom.  By moving the handle, you can probably see the cable sheathing tense up.   
    Brakes are important.  Please fix them right, and don’t cheap out here.  
    The above doesn’t mean that our brakes aren’t any good, but they need more attention than the automatic adjusting variety.  On our light vehicles, they are plenty good if well tended to.  
    #252962
    Marc Lipsius
    Participant

    @mrlmd

    I understand that the rear wheels also spin the axles but when I rotate the wheels there is still the sound of scraping brake shoes against the drums and a good deal of resistance to rotating the wheels compared to the fronts which spin freely and just have a very slight scraping noise from the shoes touching the drums. I’m just wondering pow many turns can I adjust those star nuts. As far as I know the shoes were replaced less than a few hundred miles ago and I would guess rust, etc., was cleaned off the drums at that time.
    I will look again for the cables for the emergency brake but I didn’t see any when I was under the car. Where does the single cable from the handle split to form the 2 cables? Is that exposed under the car? If I pull up the emergency brake handle it sure feels like it’s doing something, ie. it’s not loose, but I’ll have to get under the car again to see what I can see.

    #252963
    newkitman
    Participant

    @newkitman

    You’ll have to pull the rear brake drums to where the e-brake cable connectes to the arm on the brake shoe. But I always go simple (easiest) first. Pull the e-brake lever boot. You’ll see two double nuts (one on each side) that allow you to adjust the e-brake cables. Back off the star adjusters till the wheel just does turns freely. Then loosen those two nuts on the e-brake lever and adjust the lever until you get three click on the brake handle. That should be full engagement of the e-brake. As the brakes wear and the cables stretch, you make the adjustments at the e-brake lever.

    Allen Caron
    VW based 53MGTD - "MoneyPenny"
    "If one thing matters, everything matters" - from the book The Shack

    #252964
    Royal
    Participant

    @royal

    The two cables for the emergency brakes run directly from the rear shoes through their sheathing to the brake handle itself.  So, they don’e “split” as they are never a single cable.  It could be that the emergency brake cables are slightly too tight and do not allow the drum to rotate freely.  Perhaps, you should loosen the emergency brake adjustments (under the boot at the handle) and then see if you can adjust the drums.  You may have to remove the drums to see what’s going on inside there.  It’ll require a special 36mm slap wrench and even then, you really gotta whack it.  The axle nut is torqued to about 300+/- ft lbs.  That’s a lot.  I broke a 1/2″ Snap-On breaker bar trying to get it off without the special wrench that is available from VW suppliers.  

    #252965
    Marc Lipsius
    Participant

    @mrlmd

    That’s very helpful, from both of you, thanks. I’ll get into and under it again tomorrow.

    #252966
    edward ericson
    Participant

    @edsnova

    Per Muir. Tighten the adjuster star until the wheel won’t turn by hand. Then loosen it one or two pries. The wheel ought to turn freely then.

    It doesn’t? One of two things is wrong.

    1. The drum is out of round. Pull it and have it checked for roundness & cut it true if needed–or replace.

    2. The shoes, they bind. This is what was happening on the fronts of my car a couple years ago. They were old and crumbly and, apparently, little chunks of shoe material were jamming between the drum and shoe proper. I replaced the shoes and wheel cylinders and put in new spring hardwares (cost: like $6 a side or something) and now she stops straight and true.

    Need to adjust the star wheels at the beginning of each season, which I do after spring shakedown.

    Since you’re on the backs here my guess is it’s shoes/rusty hardware. As Roy points out, it’s a bit more complex back there cause of the ebrake junk, but not too hard to figure. I suggest you get a big-ass socket and a prybar, pull the rear drums and inspect. Anything wrong will be obvious & easy to fix.

    This too, just occurs to me: Did the shop that replaced the rear brakes retorque your drums to the correct 270-300 foot-pounds? If not, you might have a little “wow” on one side or th’other. Check it by picking up one side at a time, blocking everything solid, and grabbing the rear tire at 6 and 12, 3 and 9. Try to wobble it. If it’s not tight you’ll feel it. Tighten to 300 foot pounds by means of either a

    1. Big-Ass Torque Wrench, or

    2. 24-inch socket extension. If you weigh 150 stand on the end of it (full weight, no bounce) to get 300 pounds torque. If you’re more or less girthful the math is easy & we’ll help if you need. Hopefully that’ll get it. If not you’re into a new outer bearing, but probably that won’t be the prob.

    #252967
    Dennis Brock
    Participant

    @dbrock

    An off-the-wall thought.  Brake hoses can internally delaminate and the hanging piece of rubber inside can keep the brake from releasing fully.  This can cause a pull or make that brake run hot.

    #252968
    Marc Lipsius
    Participant

    @mrlmd

    I have to check my bills and with the mechanic – I know for sure he did the fronts, but I have to see if he did the rears too. I’d bet it’s rust in there, between the drums and pads. I adjusted the stars, the wheels spin easier now, the brakes work fine, the emergency brake works much better, the right rear hub is no longer hot when I come back from a ride, but there’s still some scraping noise when you rotate the wheels.
     I also have to ride it more instead of letting it sit, with all the salt air down here right on the Gulf of Mexico. There’s a medical term called “atrophy of disuse”, and besides to the human body, it applies to all sorts of mechanical things.
    I wonder if there’s a way to blow out the dirt and rust without taking them apart, but the best thing to do is get another 2 cotter pins and borrow the big socket and breaker bar from a friend and take the damn wheels off and look inside.
    The car would probably be quicker and get better gas mileage without having even slightly binding or rubbing brakes.

Viewing 9 posts - 1 through 9 (of 9 total)
  • You must be logged in to reply to this topic.