Rear dumb breaks binding.

Hi all.

My Rear Drum breaks on my KZH106 4WD SC are binding. I’ve loosened them multiple times using the lil cog wheel trick and a couple screw drivers but after driving for 10mins they start binding. I had loosened them once and then took the van to the Warrant of fitness centre 5 mins down the road and then the left rear was binding allready and the right rear was still free. I think that the left rear is having issues retracting when breaks are applied and since I’m guessing the rear breaks auto adjust to each other that the rear right break is just adjusting to the rear left, making them both bind up.

Any help would be greatly appreciated. Thank you all loads.

Could be the wheel cylinders. I think that is the name.. the bits that push the brakes out when the fluid gets pushed into them.

Maybe they don't want to go backwards.

Hello Coleyflower.

When I saw your post I thought I’d replied to a similar post on binding of front disks and it turns out this was from you. Did you fix those and what did you do?

Rear drum brakes (pure drums, rather than rear disks with drum handbrakes) are practically the same on every Toyota. The best and most likely fix is to service them and the manuals and relevant YT videos are the best way to do this. The problem, as NickZ points out, could be due to the wheel cylinders but I think you are also more likely to have binding brakes when the shoes are more worn out.

If the fronts were binding and also the rears, then this is maybe related to fluid / (rear cylinders / front callipers) and maybe the master cylinder pushing fluid through, and it not coming back when the pedal is released. This might be related the servo leaking vacuum so the brakes are pushed on a tad.

A couple of other points might be to ensure the pedal is in the right place and the springs are all attached and correct (also in the wheels btw). It might also be the master cylinder needs a rebuild / replace as it could be not releasing correctly.

Hope this all makes a bit of sense? If you can say what you did to fix the binding front brakes then this would be helpful.

Another point is that the fluid might need flushing through. Most cars should have the fluid changed every few years as it absorbs water and when fluid containing moisture gets hot then it expands and is more likely to push on the brakes.

Sorry to not be more precise, but a bit more info might be helpful on what you’ve already done first?

That you have had problems in the balance of the brakes suggest they do need a service.

Oh and the foot brake operates the wheel cylinder (obvs) but if you have typical rear drum brakes (pure drums, rather than rear disks with drum handbrakes), which I expect you have then the handbrake does the take-up adjustment in the brakes. At the end of adjustment / service you should pump the handbrake to set the brake shoes correctly, then the foot brake will actuate the brakes when in motion. If the handbrake mechanism is not working properly then the shoes won’t set properly. So, another place to look is that the handbrake!

HTH and do report back.

Very interesting about the handbrake function, I would never have thought that.