Puzzle Time - 69 Locking Up When Braking in Reverse?

[Brand138]

Good afternoon all!

I am hoping someone could help me figure this one out...

After a successfully running for about a week, I parked the patrol in the garage so that I could work on some of the grime and rust. Now when I go to reverse it out of the garage, the moment I hit the brake (inclined driveway), the patrol locks up hard and fast, giving me quite the jolt.

This is especially odd since I was previously unable to keep the parking brake tight enough to hold it on the incline. Now after it locks up it is strong enough to sit on the incline with not even the parking brake or gear engaged. Getting it to "unstick" is not an exact science I have figured out yet. It seems to disengage if I basically shift, throw the parking brake on and off, and engage and disengage the winch.

Once I reset everything and get it "unstuck" I can drive forward just fine as it does not seem to cause this issue at all (though I'm only driving maybe 15 feet).

Any thoughts? I am new to all of this so I appreciate any advice!

Thank you for your time.

[Esteban]

I can only suspect oil or gease contaminated brake shoes and drums.

You could probably spot traces by looking on the back of the drums to pinpoint the culprit one.

[RiverPatrol]

First off, unlike most other vehicles the parking brake has nothing to do with the rear brakes. As Esteban suggested you might check the condition of the shoes and drums. Another thing to look at is the orientation and placement of the brakes shoes and springs. It’s possible that a spring wasn’t replaced correctly or a shoe is cocked somehow, causing it to bind.

[moore_rb]

Possible that one or more of your rear brake shoe retaining springs are broken, which is allowing the brake shoes to shift into a position that is causing the binding... ???

[Peter60]

I've had the brakes lock up when the brake binding came away from the metal of the brake shoe. The binding then moved and jammed against the drum and locked the wheel.

[Brand138]

Thank you all so much for the help so far. I have never had drum brakes so this is all good information to a novice.

I decided to go through all the brakes and just took off the front driver side first. The drum really did not want to come off and I noticed that as I spun the wheel the brake would grab about half the time, the other half of the spin it would be loose. This is after adjusting them with the bolts on the dust cover side. Am I just adjusting them unevenly?

I suppose I should get brake cleaner and take apart and clean everything, I will try to update on what I find as I work through each wheel. One of them must be the seizing culprit! I am not sure how to test the springs, but I tried just press/pull with a screwdriver and they didn't move so I assume they are at least not totally shot on this wheel.

Other than that here is what was waiting for me, I'm not sure you can see its a bit blury but there were spider webs - whatever spiders where in there are dizzy now haha:

[Brand138]

*update*

I think I may of found the culprit.
The rear drivers side brake will not completely loosen up even when I loosen the adjustment screw. It will however tighten to a stop.

I will try to get the drum off and see what's going on, but may be impossible if the brakes are still engaged like this.
Is it a bad idea to try to remove if the shoes are still contacting the drum?

[RiverPatrol]

Sounds like you found the likely place to look. It ok to remove the drum when the shoes are still in contact, that is usually the case. It’s just a lot harder.

[Esteban]

By the way the adjuster bolt shape is, once you try to backup one step position, it momentarily tightens the shoes before coming to the rest position, and so for for probably a couple more steps. Each time you’ll feel less resistance of the shoes.

Give it a try. Otherwise the adjuster internals might be seized.

[Brand138]

I see thank you.

From what I am feeling, if I tighten it up I can hear a few clicks, but after I losen it only clicks a few times then no more clicks - the bolt just keeps turing with no clicking and no further loosening. Maybe I should take the adjuster plate off and check that first...