NCC-2569

iTrader: (1)

Hi all,

my rear brakes keep sticking and I can't seem to solve it, neither can my mechanic.

I bought the vehicle mid 2011. The brake shoes were installed incorrectly: long shoe up front, short shoe on the rear, IIRC, but brake behavior was normal, except for this:
Usually there's a linear increase in brake power and pedal travel, but after a couple of hours without movement the first two or three times I braked, the rear fully reacted to about only 1cm of pedal travel. Very hard to have them not lock up with that.

So aside from that, the wheel cylinders were leaking so we decided to replace them and also give the rears new shoes and springs and install them the right way -> brakes permanently engaged, piping hot drums.

Installing them incorrectly again caused the brakes to work "normally" again, except for the sudden lockup situation.

So I then gave the vehicle a new (remanufactured) master brake cylinder, bench bled it, added a new used stock disc/drum prop valve which I cleaned before and checked the seals of -> problem remains AND from time to time the brake drums still get hot.

So I reversed the shoe installation order myself this time, to see whether the situation has changed -> permanent engagement, very hot drums
And again reversed THAT installation (so the shoes are installed the "wrong" way round right now) -> less heat, still some engagement, not always the same amount of heat and not always identical on both sides.

Even if I back up the adjusting wheels fully and do some backwards braking until it stops clicking/adjusting, the problem returns.
Handbrake is not engaged.
Drums slide off easily, no resistance at all. When rotating the entire assembly the only resistance is the expected differential/transmission inertia (which was the same with the drums off).
Brake fluid is from January.
Hoses from mid 2011.
Spring kit, shoes and wheel cylinders from December 2012.

I suspect the rear brake hose because everything else except the brake LINES and drums and this hose has been replaced. Even though the hose it not that old.

Please share your thoughts about this. Any help will be greatly appreciated.
I have absolutely no idea why I can only drive with incorrectly installed brakes!

ternandes

iTrader: (7)

Sounds like the brake hose has interior delamination. This makes it act like a one-way valve, not allowing fluid pressure to bleed back when the pedal is released.

NCC-2569

iTrader: (1)

That's why I suspect the hose, too.
It's just so strange that the drums come off without any resistance and even the brake shoes sit right at the pin/bolt/whatever in the top center.
Of course, if the pressure is still on the other side while I'm removing one side...
damn, I just hope swapping that hose solves this crap.

ternandes

iTrader: (7)

Not entirely sure why reversing the shoes helps, but I think the reason why you can pull the drums is that the pressure eventually bleeds off.

NCC-2569

iTrader: (1)

I guess it does.
If it would just do that while driving!

Btw: They are gripping so tight, that I don't need to stay on the brake when I put the transmission into reverse, but only in reverse the car just sits there.

Update:
Replaced rear brake hose, brakes still sticking.
Took the old hose apart: Clear passage. No blockage or deformations to be seen.

The drums are still piping hot to the touch.

Now everything from front to back, except the hard brake lines and the drums themselves, is new and still I have to put in the shoes back to front to reduce unavoidable sticking.
Any further ideas? I'm out of 'em.