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Discussion Starter #1
Bought this '74 coupe with standard drum brakes. These things came with power drums, so I ordered (off e-bay) a CHROME master/ booster, kit claimed to be an exact replacement. Replaced all rubber brake lines, new wheel cylinders and shoes all around. Went for a long drive. well not too long BRAKES LOCKED UP too hot. Cooled off drove home. Chrome mstr leaked, ruined chrome booster. Threw it all out and got a new iron set. Pro installed new set (he ordered) Same result. Pro reinstalled correctly, adjusted the master all works as drums should. EXCEPT I still have at least one warped drum. I've got some ideas how to find it, but I'm looking for quick and easy narrow it down then precisely check.

Do the shoes warp when drums get real hot. I know on my model A it was recommended the shores be arched to the drums. I've looked at the shoes. Not crystallized or cracked (The old ones were a mess)

Any help is appreciated.
 

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Did the boosters have adjustable pushrods? The only time I ever had a lock up issue with drums was with a **** Chinese booster that had an adjustable pushrod that I didn't know was adjustable, lol.
 

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unfortunately I didn't know weather or not the push rod was adjustable. I believe the pro told me he ground off some of the second set push rod to get it right. But the real deal now is the remaining damage? Around 35 MPH after 10 minuets or so of driving I get a slight harmonic vibration as if there is a bad wheel bearing and the car pulls to the right have yet to try a panic stop
 

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Did the boosters have adjustable pushrods? The only time I ever had a lock up issue with drums was with a **** Chinese booster that had an adjustable pushrod that I didn't know was adjustable, lol.
Yes Sir and adjustable or not the depth and rod length should always be checked. Not hard to check real quick before assembly.
'
 

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unfortunately I didn't know weather or not the push rod was adjustable. I believe the pro told me he ground off some of the second set push rod to get it right. But the real deal now is the remaining damage? Around 35 MPH after 10 minuets or so of driving I get a slight harmonic vibration as if there is a bad wheel bearing and the car pulls to the right have yet to try a panic stop
Doesn't sound like the length is correct, and may still be causing the brakes to stick and drag. Heat could have killed a bearing that was already about to need replacing, or it's completely unrelated... Get it up in the air and see how the wheel feels, then drive it around the block a couple times and go heavy on the brakes, get it back up in the air and see if the wheel feels different. Could be dragging when hot. Could need further adjustment at the booster. Could have bad wheel cylinders.

Might be time for wheel bearings!
 

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Discussion Starter #7
ok got ya. we have new wheel cyl, lines, shoes, springs kit. funny I'm an old hobbyist. run it around the block hard is OK getting it up off all 4 takes me about 2 hours with breaks. but I'll be on it. Its our daily driver so I'd like to have it right. Thanks for the help
 

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Discussion Starter #8
OK, well here I am again with my front DRUM brakes not fully releasing. I took some pics. I think the shoes need a sanding to get the glaze off but I also noticed the small push rods from the wheel cylinder to the shoe had a little difference in the ends where they pushed on the shoes. The end resembles an "H" when looked directly at the end. WELL, two legs of the H are bent to the rear and two are at 90 degrees to the face. The pics here are worth a thousand words. Look at the upper fingers on the push rod at the shoe.
Today I'm going to set up with a dial indicator and check the drum for eccentricity, sand the shoes and turn the push rods over so the bent fingers are on the bottom.
What could it hurt? Any suggestions?
 
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