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View Full Version : How come my brake self adjusters won't self adjust?



aggressive male
02-13-2007, 12:09 AM
I'm wondering why my rear brake drum self adjusters don't seem to be adjusting, I took off the drum and I can turn the adjuster by hand and it ratchets against the self adjuster as I turn it by hand. Am I supposed to drive fast backwards and slam on the brakes hard to get the self adjusters to work or is just normal driving supposed to adjust them? Thanks

MonzaRacer
02-13-2007, 12:46 AM
Ok first of all you do have to back up AND leave your foot on the brake pedal and shift to drive and let the car "set" forward and the brakes should adjust.
The big problem is that most people dont understand that drum brakes need to be adjusted up till they just drag with a 2 hand turn. BUT if you do this keep smacking the drum on the edges so as to settle the shoes and remember to turn both directions as you adjust.
The big problem is that most brake systems have contaminated fluid and you should flush the system very thouroughly and make sure the wheel cylinders are free in both directions as they some times will freeze up one piston and not adjust properly.
Not knowing what brand of car you have you need to make sure that either the link bar or adjuster cable is installed and not damaged or missing.
Also make sure that the adjusters are on the proper sides too.
All you should realy need to adjust the brakes is simply a 5 to 10 mile per hour roll backwards and firmly stop the car to allow the brakes to rock backwards then with your foot on the brakes move the car forward to adjust the brakes.
Yes they will adjust going forward but not as much or really good.
Also make sure the drums are NOT oversize as that will trash the geometry and the brakes wont even work properly.
So get those drums either replaced or atleast measured and make sure they are in spec, cause if they are not its actually dangerous as when the shoes get too worn you will have a bad brake pedal and maybe even the brake light coming on. I had asimilar problem with my truck and the drums were over 0.250" over size and made me change my mastercylinder before finding the drums bad.
Good luck and ask any question if you are confused.
Lee Abel

aggressive male
02-13-2007, 01:20 AM
Ok first of all you do have to back up AND leave your foot on the brake pedal and shift to drive and let the car "set" forward and the brakes should adjust.
The big problem is that most people dont understand that drum brakes need to be adjusted up till they just drag with a 2 hand turn. BUT if you do this keep smacking the drum on the edges so as to settle the shoes and remember to turn both directions as you adjust.
The big problem is that most brake systems have contaminated fluid and you should flush the system very thouroughly and make sure the wheel cylinders are free in both directions as they some times will freeze up one piston and not adjust properly.
Not knowing what brand of car you have you need to make sure that either the link bar or adjuster cable is installed and not damaged or missing.
Also make sure that the adjusters are on the proper sides too.
All you should realy need to adjust the brakes is simply a 5 to 10 mile per hour roll backwards and firmly stop the car to allow the brakes to rock backwards then with your foot on the brakes move the car forward to adjust the brakes.
Yes they will adjust going forward but not as much or really good.
Also make sure the drums are NOT oversize as that will trash the geometry and the brakes wont even work properly.
So get those drums either replaced or atleast measured and make sure they are in spec, cause if they are not its actually dangerous as when the shoes get too worn you will have a bad brake pedal and maybe even the brake light coming on. I had asimilar problem with my truck and the drums were over 0.250" over size and made me change my mastercylinder before finding the drums bad.
Good luck and ask any question if you are confused.
Lee Abel
Thanks MonzaRacer!

Thats just the answer I was looking for. THis is for a 77 deville by the way. I don't think I have contaminated fluid because I had to replace lines a while back due to salt. I don't think my drums are oversized because I replaced them for being flaky. I guess that could be my problem that I didn't know that shifting back to drive while on the brake was also part of adjusting it. Now by two hand turn do you mean I should adjust it so there is so much drag I can barely turn it with 2 hands? Also is duralast a decent brand of brake shoe? WHen I put the shoes into the adjusters grooves there is a lot of slop in it, is this normal or does this mean duralast is cheap and made of thinner metal? Thanks

Madspeed
02-13-2007, 09:54 AM
besides What abe said.
I would adjuts the shoes with drums on untill you can tighten the adjuster any more and you can not turn the drum.
back off the adjuster untill you have a drag on them and wala your done

aggressive male
02-13-2007, 11:11 AM
Thanks Madspeed,
I'm still not sure just how much drag is appropriate though. If I have too much drag wont it glaze the drums and pads? Also is it ideal for it to have drag like that at all times or only when you are breaking in new pads and drums? thanks

Madspeed
02-13-2007, 08:33 PM
you are adjusting them as tight as you can to seat them and center them.
you back them off untill you know they arent to far away IE light drag.
you just want to know they are near the drums. Very Near.
otherwise you will have to pump the brakes to get the shoes out and a firm pedal.
No you do not want them to dragg and cause heat or they might heat up and swell as well as heat the fluid and expand it as well causing even more drag. You can see where that will go.


Hope that makes sense

aggressive male
02-13-2007, 08:49 PM
I think I got it all right today, much firmer pedal now, thanks Madspeed, thanks MonzaRacer!