Yeah, that pretty much sums up his reply right there.
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Problem with rear drum brakes, I'm out of ideas.
- Thread starter msell66
- Start date
kb3
Well-Known Member
I would be tempted to spray a light coat of paint inside the entire drum and then install it. Should rub the paint off somewhere!?
It sounds like you've discounted this idea because other "reputable" shops have looked at it.... yet none have come up with an answer.
You can trust anyone's work, but when issues arise, go ahead and verify... hence why I suggest checking the drums run out... preferably bolted to the same axles. Just bolt the drums on "inside out", and set up a dial indicator to read the turned surface.
I'd imagine an untrue surface would float some when turning by hand, and become more resistant when bolted down. Since the drums are hub centric, is there any slop between the drum's bore and axle's hub? what about the axle studs, are the splines protruding through the axle flange too much and not clearing the stud holes in the drum?
By the way, I've seen some brake lathes with a bit of a wobble on their spindles that would obviously translate on to the disc / drums. Perhaps not enough to cause an issue with street pads, but maybe enough to exaggerate the drag with performance pads.
Not discounting at all. As a matter of fact you're on the same path I have been on with this since the start. Prior to this thread I asked Mark to take his axles over to the guy who built my rear end so they could check them out. And for the record, he has tried two sets of drums and had the first turned and then checked AGAIN to verify they were not out of round, etc. I'm of the mindset now that when torqued down something in the axles, studs, drum is getting, in technical terms, out of whack do to some incorrect contact surface issue. And to answer another question you pose, Mark says the the hub centric hubs fit perfect on the axle hubs.
I'm done racking my brain from afar. Going to wait and see what this qualified Ford tech says this weekend.
Never fails. Got stood up by the Ford tech 
Mark
Mark
tarafied1
Well-Known Member
bummer, I'm curious to know what's up with these things!
Grabber70Mach
Well-Known Member
I'm with Craig but will add unless he has a good excuse may the fleas of a thousand camels infest his house.
So, I changed from the stock 10x1 3/4 drum brakes to 11x2 1/4 last year. New everything including the backing plate. Since installation, I've had this same problem.
When I put the drum on the axle hub and then snug up the brake shoes so they just start to get drag, I can easily spin the axle with my hand. If I either tighten the drum down with lugnuts only of wheel and lugnuts, I can no longer turn the axle or tire by hand.
Things I've checked:
Axle flange runout checked out less than .003"
Axle is square to the flange
New axle bearings
Drums have been turned
Shoes sit fine depthwise into the drum. They are not touching the drum anywhere except the shoe face.
The shoes are the correct radius and fit the drums perfect.
I've used white chalk everywhere to see if there is rubbing. No witness marks other than the shoe face.
If I adjust the shoes in at the bottom so that when tightened down it does not affect turning by hand, the brakes don't do squat when the brake pedal is pressed. If I do adjust the shoes so they have the correct drag and then tighten them, I get major brake fade pretty quickly on track and the drums get super hot.
I have yet to check if the backing plate is square with the axle flange. That is the last thing I can think of to test. I've discussed this with John at ORP and he said no one else has had this problem with this larger brake kit.
I realize that due to the drugs I've had over the last 3 years, I'm limited in my ability to diagnose problems. So now, it's up to yoose guys!
Is the picture the left or right side. Which way is forward? There should be a primary and secondary shoe on each side. The materials can be different. The forward shoe helps the brakes apply and must be the forward shoe. There is a left and right adjuster also. There is an L & R on the inside of the short cap. Did you tighten the adjuster just till you couldn't rotate the wheel or until the adjuster was difficult to turn?
So, I changed from the stock 10x1 3/4 drum brakes to 11x2 1/4 last year. New everything including the backing plate. Since installation, I've had this same problem.
When I put the drum on the axle hub and then snug up the brake shoes so they just start to get drag, I can easily spin the axle with my hand. If I either tighten the drum down with lugnuts only of wheel and lugnuts, I can no longer turn the axle or tire by hand.
Things I've checked:
Axle flange runout checked out less than .003"
Axle is square to the flange
New axle bearings
Drums have been turned
Shoes sit fine depthwise into the drum. They are not touching the drum anywhere except the shoe face.
The shoes are the correct radius and fit the drums perfect.
I've used white chalk everywhere to see if there is rubbing. No witness marks other than the shoe face.
If I adjust the shoes in at the bottom so that when tightened down it does not affect turning by hand, the brakes don't do squat when the brake pedal is pressed. If I do adjust the shoes so they have the correct drag and then tighten them, I get major brake fade pretty quickly on track and the drums get super hot.
I have yet to check if the backing plate is square with the axle flange. That is the last thing I can think of to test. I've discussed this with John at ORP and he said no one else has had this problem with this larger brake kit.
I realize that due to the drugs I've had over the last 3 years, I'm limited in my ability to diagnose problems. So now, it's up to yoose guys!
These are not “Ford” brakes. The R4 shoes are the same size as always. Porterfield does not make the shoes different sizes and they worked fine on the old brakes.
I’ve given up and just adjusted them with the wheels on. I’ll see how they work at the October race.
Mark
I’ve given up and just adjusted them with the wheels on. I’ll see how they work at the October race.
Mark
Mach1Rider
Active Member
Have you tried to verify the housing ends are square to the center section?
I had like problem and it came down to the housing ends were bent ever so slightly from previous accident.
The dragging hub only appeared when the wheels were on tightly.
I had like problem and it came down to the housing ends were bent ever so slightly from previous accident.
The dragging hub only appeared when the wheels were on tightly.
Mach1Rider
Active Member
Reading thru this in post 27 you found the problem. The drums are binding on the backing plate.
Look for the reason this is happening, drum depth to deep or axles set back too far in.
I saw where the axles have new bearings installed, they may have been set too close to hubs.
Look for the reason this is happening, drum depth to deep or axles set back too far in.
I saw where the axles have new bearings installed, they may have been set too close to hubs.
The drums are not contacting the backing plates. There was no difference before or after bearings were replaced.
Mark
Mark
When there were only drum brakes and before automatic adjusters, I used to adjust then until the adjuster was tight and you could not turn the wheel in the forward direction. Then back it off until the wheel would almost turn freely. That way you were sure the shoes were centered. All done after turning the drums and radiusing the shoes to fit the drum. Nobody radiuses the shoes any more.
JeffTepper
Well-Known Member
The shoes fit the drum radius. Both sets, the stock type and the R4’s.
Mark
Mark
So, Quick Performance is here in town. They had a set of 11” x 2 1/4” rear drum brakes for the small bearing 9”. I bought the pass side to swap out what I have on the car. Sure enough, the problem is fixed. It’s been the backing plate all along. Now I can adjust the brakes so they just start to drag, mount the wheel and it still turns fine. Bought the driver side today and will swap that out soon.
Now it all works with the same parts and drums, just the backing plates has changed! They are either bent or where the shoes contact, they’re not even. The drums have never made any contact to the backing plate.
Mark
Now it all works with the same parts and drums, just the backing plates has changed! They are either bent or where the shoes contact, they’re not even. The drums have never made any contact to the backing plate.
Mark