Front brake binding

[JonnyP]

My latest issue is a binding left front brake. It’s not 100% locked and still works, in that if I push the brake pedal it locks and releases a little when the pedal is released, but I can hardly turn the wheel by hand. All three other wheels are fine. Backing the adjusters right off makes no difference, so I guess the shoes are jammed somehow, but it is so tight I cannot get the drum off.
Does anybody have a method of removing the drum in this situation?

Many thanks

[Ray White]

I am assuming you have removed the two small countersunk screws!

What I imagine has happened is that your wheel cylinder has rusted slightly and will not allow the piston to fully retract. If that has happened and the shoes have worn a depression in the drum, the edge of the shoe may be catching on the slight ridge in the drum. I would suggest you back off the adjusters and whack the front face of the drum with a heavy wooden mallet in the hope that the shock may be enough to free the shoes.


I would be very careful about using heat but if the drum is REALLY stuck then it may be necessary.

[i.thomson]

Undo the bleed valve to eliminate retained fluid pressure to be the problem. If so, suspect the flexible pipe. Have you recently changed to silicon fluid? If so suspect swelling of the seals covering the small return hole or perhaps just a blockage in the master cylinder due to muck.
Ian

[Steve Simmons]

Most likely it's an old brake hose failing. They swell internally and act like a one-way valve, letting fluid to the brake but not back to the master. If the hoses are more than a few years old, I would replace them all. There may not be any external evidence of age or failure even if the inside is failing.

Beyond that, It would have to be an mechanical issue. It can't be the master or all the brakes would have the same issue, as this is a single circuit system! Things to look at would be a sticky wheel cylinder, bad return spring, or the shoes hanging up on the adjusters or related hardware. Opening the bleeder on that wheel may release the brake. If not, gentle tapping with a mallet might do the trick, or possibly using a puller. Use care to not bend the drum. Use even more care if they are alloy drums!

[JonnyP]

Thanks all for the suggestions. No recent changes to the system and was fine until a few days ago. I shall try your suggestions on Friday and report back.

[JonnyP]

Thanks to the suggestions from this group, I managed after some hammering and levering to get the drum off. Couldn’t find a specific problem, but it is apparent that the shoes are very old and have been re-lined many times. The pivot holes and somewhat oval and surprisingly the posts upon which the adjuster act have deep grooves worn in them by the cams. So my thought it that all of these have compounded to cause the jam.
On the plus side the (steel) drums are in good condition, the hydraulics sound and the shoes worn evenly across the majority of the friction surface.
The brake performance has always been poor, so this may be my opportunity to replace the shoes for new ones. Based on previous TABC posts I’ve read, I like the sound of the Green Gripper material mentioned by Tom Wilson. Does anybody know whether there is a supplier for new shoes with that material fitted? Also, does anybody have direct experience of the Mintex lined shoes that Peter Edney sells?

Many thanks

[Duncan M]

While you have it apart, be sure and check the condition of the front hubs. They are known to wear out where the bearings press into the hub. They may press in with the right amount of resistance, but once fully "in" they may not be tight. Known as worn out hubs.