Drum Brakes Over-Adjusting - Solved

[Guggenheim99]

02 Ranger 10" drum brakes. Old parts were seized, rotted out, and parking brake getting stuck on. Parking brake cables also were worn through where it passes through frame and ready to brake. Replaced everything. OEM parts. Get it all together and adjust out till slight contact is heard. Road test and can hear clunking from inside rear drum on driver side. And can notice truck has drag. Jack truck back up and driver side is very tough to turn. Passenger seems ok. Remove drum and found it is over-adjusted compared to passenger. Spin it back in and reinstall drum and tire. Adjust again and test drive with same result. Drive it for the week to see if maybe shoes needed to be broken in. Still have issues. I verified all components installed correctly. The auto-adjuster is functioning correctly (as in slack adjuster is pulling on adjuster and adjusting the star wheel) it just seems to be over-tightening that side. I started over again today and as the shoes got closer to the drum, as I was turning wheel by hand, I was watching through the adjuster hole in the backing plate and was able to watch the whole adjuster (presumably shoe assy too) move and wheel would get very difficult to move. Then would hear a light clunk and would be easy to turn again. Ran truck in drive on jack stands and carefully watched through the hole and the adjuster (presumably shoe assy too) shifting forward and backwards as the tire is turning in drive. Hard to explain. Only thing I can describe is the drum is warped and the shoes are matching the warp. I moved the drum to the passenger side and seems like the hard-to-turn wheel condition moved to that side but have yet been unable to duplicate the clunk from inside the drum. Maybe I have to drive it more. Does anyone know if a warped drum can cause an over-adjusted concern? Thinking maybe it matches the adjustment in a normal part of the drum but then when it reaches a warped part, it gets tight? Kind of lost. Have spent 3 full days screwing with this and have ended up with more questions then answers. Makes me appreciate disc brakes way more. Haven't smoked the shoes yet but want to fix it before I take on longer drives. Any advice is greatly appreciated.

 

[Uncle Gump]

Have you checked the runout on the axle?

 

[Uncle Gump]

I would also ensure the tops of the brake shoes are fully seated on the anchor pin.

 

[Uncle Gump]

I'll say too... there was a fella not long ago thought his brakes were dragging after all new parts.

It ended up bearing an axle bearing getting hot and dragging.

 

[Guggenheim99]

Did not check axle runout. Only because the condition was not occurring with the old parts installed. Shoes installed on anchor pin correctly. Good point about axle bearing. I had moved the drum in question to the other side and will drive it for a few days and see if the condition moves. Thanks for the ideas

 

[alwaysFlOoReD]

Does the curve of the shoe match the curve of the drum?

 

[Guggenheim99]

Does the curve of the shoe match the curve of the drum?

Not sure what you mean. I see the adjuster moving back and forth as the wheel is turning forward. Always in the same spot I think. Is that what you meant?

 

[don4331]

Not sure what you mean. I see the adjuster moving back and forth as the wheel is turning forward. Always in the same spot I think. Is that what you meant?

I believe he is wanting you to confirm you receive 10" shoes for 10" drum; not say 9" ones..

 

[Guggenheim99]

I believe he is wanting you to confirm you receive 10" shoes for 10" drum; not say 9" ones..

Yes, verified part numbers and measured components and they are for 10" application

 

[pjtoledo]

Does the curve of the shoe match the curve of the drum?

that's where you lay the shoes inside the drum then check for even contact all around.

 

[pjtoledo]

Not sure what you mean. I see the adjuster moving back and forth as the wheel is turning forward. Always in the same spot I think. Is that what you meant?

something is out of round. mark drum & hub, rotate the drum 2 holes and repeat.

you can smear magic marker inside the drum to show hi spots.

 

[alwaysFlOoReD]

that's where you lay the shoes inside the drum then check for even contact all around.

Yes, as drum are turned on a lathe the radius increases. Maybe you got shoes meant for a different radius.

 

[19Walt93]

I've only see drum brakes self adjust too tight if the drums are out of round. The clunking noise would make sense if that's the case. Try switching the drums side to side, I'll bet the problem moves to the other side. In the distant past they used to rearc the shoes to match oversized drums, I've never done that. I adjust them and drive the vehicle for a while and wear rearcs them.
They also used to turn drums much more, most now are limited to .060" or .090". A 35 pickup I rebuilt years ago had drums 1/8" oversized so we had to put shims under the linings before riveting them to the shoes. 1935 brake drums were one year only parts and their made out of unobtainium.

 

[Guggenheim99]

I did not lay the shoes in there and check. I did switch the drums last Saturday but it's been single digits/below 0 all week so haven't been able to investigate if the concern moved. Should warm up this weekend so will look and update as necessary. Thanks for all the info

 

[Guggenheim99]

So have an update. I checked the runout on both drums and they measure between .020" - .024". While I found no spec in either the main workshop manual or the specification manual, I feel that is way out. Guess it makes sense because the shoes would adjust to the low spot in the drum, then when the high spot comes around, it binds up. Would also explain the clunking and movement I see from the shoe assembly. Now I just have to get time after work to machine them. Hopefully our brake lathe still has the drum attachments laying around somewhere. Been years since I seen anyone use it and never seen someone do drums on it. So definitely will be a learning experience. Guess this is what I get for ordering Ford parts then waiting months and months to install them so I lose the return window. Will update when I get them cut. Thanks for the comments