brake problem

[James Hewett]

how can I find what is wrong with my brakes on a 94 GMC, right rear drum brake locks up on occasion?

[BobND]

Have you pulled the drum and looked in there?

Most likely causes are leaky axle seal, leaky wheel cylinder, or brakes worn out or falling apart.

You would think gear oil or brake fluid would make the brakes slip, however, it usually does the opposite, and makes them grab.

[James Hewett]

We have looked this all over, put in a new wheel cylinder in case the ole one was hang'n up and disconected ABS wire to that 1 brake. do you think disconnecting all ABS wires would help?Sometimes when ride'n the foot pedal a little helps, it is very noticeable on snow&ice.Is there a chance a problem with positraction?
We checked rearend oil for fullness and for leaks, no leaks !
I wonder if axle bearing is bad altough it doesn't make any noise.
Did any one ever replace rubber flex hoses for colapsing before? and the fluid doen't return to Master cylider.

[tom.mcinerney]

Flexible brake hoses do collapse internally, causing brakes to 'drag'. Replacement is cure. More common problem on front. Hose often 'bulges' at bad spot.

[G. Gearloose]

Adjustment is too loose. Loose brakes causes them to lock. I know, its counterintuitive, but clear when you see how they work.

Also, shallow bevel the leading edge of each shoe to reduce locking on first application, especially after damp weather.