moparmatt89

Hello,
I just rebuilt my rear drum brakes on my 1969 Mustang and cant seem to remember how they are supposed to be adjusted. If I recall dont you tighten them till them lock up and then back it off 20 clicks. I forgot where i heard how to do it, but i thinks thats what it was. Any suggestions would be great. Thanks alot
Matt

ideal_mustangs

Since you can't spin them like the front, just adjust them up till the drum is kinda tight going on so there will be some resistance.

Colorado_Mustang

Tighten them until you can just hear the shoe touch the drum as you rotate the tire.

moparmatt89

ok, thanks alot

Ziggysan

Waiiit... I've just replaced all four drums on my '66 Coupe, but I'm a little concerned that they are rubbing too much. I've lowered the autoadjusters as per the instructions (tight, then back off 1/4 turn) and I still hear them quite loudly (though I'm rather inexperienced with drums).

So, they SHOULD be touching the drums for a while (eg breaking in)?

Soaring

If you can get the drum on, they are not too tight. They will rub slightly until broken in, then the auto adjust takes over.

Ziggysan

Okay... thanks. Unfortunately, I found the problem is not 'light touching' -- the passenger side rear brake, forward shoe is engaging, but then won't lower back into its original position against the shoe guides, so it stays engaged. There is a LOT of upward motion on the shoe when the brakes are applied which pushes it up so that the lower tooth of the crescent that sits the shoe on the mount (round thing on top on which the springs are hooked) wedges up and won't let the shoe come down.

So:

Why is it moving upwards (none of the other shoes in the other three wheels does this)?

How can I fix it?

New wheel cylinders, new shoes, new drums, cleaned the bejeezus out of everything and all the springs are still real tight.

jdforsythe

First of all, are you sure that you have the primary shoe (smaller of the two) on the front side of the wheel ( towards the front of the car). If you have this correct, did you replace all your springs, they will lose tension over a while. Also make sure that your adjuster is in the right way so that when you spin the adjuster it is expanding and not contracting. Lastly, if you get both of the wheels off the ground (you will need some jack stands) place the car in neutral and you can spin the back wheels just fine. Adjust until you hear light friction when the wheel makes a complete rotation. Then drive it for a while. New shoes and drums need to seat themselves and be re-adjusted sometimes multiple times.

I like to have more friction than most people when adjusting. I know I will lose some life on the shoes, but it greatly reduces the travel on the pedal and helps the seat sooner. Learned all this from multiple attempts to get mine right.

Soaring

Yeah, the front side receives the short shoes.

Calixtus

I just replaced all four wheel cylinders and pads on my 68 (289, 4 wheel power drum) but I can't get the brake light to go off. The shop manual says to bleed the proportioning valve on the side opposite the circuit bled last, while the Chilton's says to bleed the same circuit, but at the wheel cylinder instead (much easier and not as messy). I bled all four, then went back and bled the right rear again to try to recenter the valve piston, but after 5-6 full pedals the light still did not turn off. Brakes appear to be stopping all four wheels. Is this critical? How do I recenter the proportioning valve piston?

Also, I have a really firm pedal when the car is off, but once it is on, the power brakes are really spongy. No brake action at all for the first two inches or so of travel. I'm thinking either I have a vacuum leak or the power booster pushrod is adjusted poorly (my mother-in-law had someone replace the booster 4-5 years ago). Any suggestions?