Decided to inspect brake shoes. No problem with first three wheels, but on final wheel, Ford truck rear brake drum wouldn’t budge. Weird sequence of events then happened. Decided shoes maybe stuck in place, not retracted, so pressed hard on brake pedal, thinking that might free them up. This completely locked the wheel, brakes fully on, nobody pressing on pedal. hmmm??.. Eventually, 15 minutes of fiddling, wheel finally unlocked. Drum still not budging. Decided to loosen brake bleeder screw, bleed off fluid pressure. No fluid came out. Removed bleeder entirely, still nothing. Expected at least a dribble, MC higher than wheel cylinder, gravity should pull fluid out.
Still had to remove drum, so improvised a mechanical puller-scheme along w/ some judicious hammering, drum finally released and popped off. Shoes & springs ok, retracted, not the cause of stuck drum. Stuck drum problem appeared to be a rust bond between drum & hub. Shoes not moving freely like they should, so lubed backing plate and adjuster, anti-seize where drum was sticking to hub, replaced drum. Retried gravity bleeding. No more than one drop a minute. Even the normal method, pushing on brake pedal, still not much brake fluid came out. More than a drop a minute though. So what’s restricting the flow of brake fluid to this wheel cylinder? Gravity bleeding worked great on front, I don’t think I’ve ever tried gravity bleeding the truck’s rear drums; maybe that just isn’t possible, maybe caused by proportioning valve?
I’m thinking I may have a problem one of the rubber brake hoses collapsing. Any other ideas?
Trash or corrosion in the brake pipes or hoses or prop valve can cause this as can the bleed hole being completely rusted shut.
Disconnect the wheel cylinder and see if any fluid comes out of the line.
I know a Californian would not expect the drum and axle flange to be bonded like this… But we rust-belt experienced DIYers know this to be a common issue. The two parts will attach themselves like they were cast from one piece…
Did you try the other WC bleeder screw to see if drips from there???
Yeah they call that time welded… penetrating oil works good sometimes…
You are just going to have to start breaking lines loose from WCs, hard line to rear hose, proportioning valve, master cylinder until you get fluid flow… Also check to make sure no hard lines are damaged (dented closed etc) and the rubber hose is not twisted for some reason…
I did apply some penetrating fluid to where each stud poked through the drum, and also the inner circle where the drum met the hub, let it work its magic overnight. Probably helped, but not enough to allow me to pull the drum off using my hands. The problem spot is probably where the main hub surface meets the drum, hard to get penetrant there via those portals.
I like the idea of disconnecting the brake line at the wheel cylinder. Easier to do than messing w/the upstream lines. Could prove the problem is just the wheel cylinder. I wasn’t planning on replacing that part until the shoes need replacement, but I could replace it, not that difficult.
You’d have laughed I think if you saw my improvised puller … lol …
Moving on fron the “Drum Edge Crud” the next logical place is the brake fluid delivery but since no fluid comes out there’s clearly an obstruction.
Again don’t know the year of your vehicle, wether the lines are copper or aluminum., maybe an appropriate solvent may be the solution.
On the other hand having a 70+ year old car with the original copper brake lines and never hading a corrosion problem, your problem may be your internally corrroded flexible lines or more llikely a questionable wheel cylinder /
That’s a good idea. I was tapping around the face with a 4 pound hammer. But an air hammer providing rapid taps seems like that method would work better. Plus it gives me a reason to purchase an air hammer … lol …
Not recommended. I don’t drink orange or grape crush. About 15 minutes later red splotches would appear all over. Something in it that no one else has. Maybe the water used.
I experience nearly exactly the same symptoms after drinking orange soda. In my case the worse part isn’t the blotches, just feel really itchy for several hours. Too bad, b/c orange soda is pretty tasty. Like you say, very few people seem to have this problem.
Ran into a little engine performance problem on truck, had to defer the brake issue for now. Test drives indicates brake performance remains very good. Biggest problem w/truck’s drum brakes has always been unequal braking causes truck to steer left or right under hard braking. But recent brake work seems to have solved that problem, very little to no braking steer now.
Whatever works!