Need help on drum brakes, please (1 Viewer)

Joined
Nov 10, 2006
Messages
84
I own a 1972 FJ-40 with drums all around. I recently had a problem with my passenger front brake dragging and almost locking up on the road. Since then, I had all the drums machined, and installed new shoes and springs.
The brakes work great, however, I've noticed that the passenger side will start getting tight again after several trips around the block. I adjusted them a few clicks looser, but the problem will return after another drive.
From what I've read here on MUD, I've narrowed the problem down to a few culprits. One, the brake hose may be defective. While bleeding the brakes, I noticed that very little fluid gets past the bleed screw, even when using my power bleeder. I believe these hoses may be original.
Or, the wheel cylinders are not retracting back fully. While replacing the shoes and hardware, I didn't notice any signs of leakage at any of the wheel cylinders.
The master cylinder/booster was replaced about a year ago, and I've checked the push rod length and pedal height. The driver's side drum does not have this problem. I'm at a loss at what to do right now, and I don't want to throw parts at it aimlessly.
Could you give me some advise on how to determine what is causing my front passenger drum to tighten up? Any help greatly appreciated.

Mahalo,

Steve
 
Joined
Nov 12, 2010
Messages
116
If nothing else is mechanically obvious, I'd suspect a wheel cylinder. Usually, anything that will extend will also retract, but I have had personal experience with an FJ wheel cylinder frozen in place due to rust. I doubt it's the hose, but you could check this and any steel line when looking at the cylinders. I didn't have the same problem you do, but upon teardown one of my rear cylinders was so frozen from rust I had to beat the piston out with a punch. It wasn't leaking, either.
 
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Oct 26, 2008
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2 1/2 Hrs. from everything
 
 
Ditto, sounds like a wheel cylinder. I bought repair kits for all of mine many years ago for about $4.00 per kit, used sand paper to clean up the cylinders....all's still well. Good luck.
 

John McVicker

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Jul 11, 2005
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Could be the wheel clys. but it also could be a collapsed rubber brake line. You can check this in 10 mins. or so.

Pull the line & see if you can blow thru it. If good, put it back on...3-4 pumps to bleed...then look at the clys.

John
 
Joined
Nov 10, 2006
Messages
84
Hey guys,

Thanks for all the suggestions so far. I have a small update.
I thought that my master cylinder pushrod was "properly" adjusted, but it turns out that it was slightly too long. Could this affect only one brake? I thought that a mis-adjusted rod would affect both brakes on the axle, but I could be wrong.
I re-adjusted the rod and shoes for that drum. If that doesn't clear up the problem, I'll check the lines and the wheel cylinders. Thanks again, all.

Steve
 

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