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Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 3:36 pm
by Mx3forever
Wow, these drums haven't been serviced for at least 12 years.

I decided to pull them apart as part of a master plan to inspect all brakes and change out all the brake fluid in the car.
After getting the drum apart and replacing the pads, replacing the springs and greasing the assembly, I can't get the drum to go back on.

I've loosened the brake fluid bleeder on the brake. I've attempted to adjust the right pad by moving the notched adjustment plate all the way in for no tension. I can't find anything else to adjust, the manual mentioned an adjustment screw, but never pointed out where it was at.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 5:07 pm
by mitmaks
http://www.mx-3.com/manuals/showimg.php ... _P-039.gif
I would make sure you've installed everything correctly, everything is lubed as per manual.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 6:31 pm
by Mx3forever
yeah, everything is back in correctly. The drums just don't want to go back.
I got one of the drums back on (although I had to hammer it to get it back on). It is tight but has some play (like a new caliper brake pad).

I'm trying the other side now. These things are a PITA.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 9:09 pm
by ganue
Have you returned the adjuster to its minimal length?

Sort of like this:

Image

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 10:32 pm
by Mx3forever
Well, a spring adjuster with teeth that I saw- I put to the minimal length (It was pulled out toward the worn pad).
I don't believe the mx-3 has an adjuster like the one in that photo.

I just didn't see anything else there to adjust.

After I pounded both drums back, so far so good. My E-brake that you had to pull up about 75% to lock the wheels, now only requires a small 20% rise. Both leading drum pads were shot- partly down to the metal. The secondary side (non-e brake) was ok. I also bleed the whole system of old dark brake fluid from both drums and calipers, bleeding out about 25 oz of fluid.

Who knows, depending on the third party pads and the rusty condition of a drum, perhaps I'm not the first to hammer a drum back on.

(DUH!) I actually took pictures of the drum to make sure I rebuilt it the same way.
I'll throw up a couple photos and perhaps someone can jump in that way.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 11:06 pm
by mitmaks
Maybe someone adjusted ebrake cable to tighten it up? You might have to loosen it up to get drums back on and then readjust it.
Check your auto-adjusters
http://www.mx-3.com/manuals/showimg.php ... _P-040.gif
http://www.mx-3.com/manuals/showimg.php ... _P-042.gif

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 11:26 pm
by Mx3forever
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Outside of making sure the pressure is off the piston and both pads are as close as possible, I don't see anything else to adjust except for a
little plate with teeth and a spring. I reset it back since it was pulled out due to the worn pad.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 11:28 pm
by Mx3forever
mitmaks wrote:Maybe someone adjusted ebrake cable to tighten it up? You might have to loosen it up to get drums back on and then readjust it.
Check your auto-adjusters
http://www.mx-3.com/manuals/showimg.php ... _P-040.gif
http://www.mx-3.com/manuals/showimg.php ... _P-042.gif
No, that wouldn't be it because the E-brake wasn't even engaged.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 27th, 2013, 11:38 pm
by mitmaks
Make sure wheel cylinder pistons are all the way in. Did you inspect wheel cylinder while you're at it? Pull rubber boots back and check for leaks.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: July 28th, 2013, 4:35 pm
by mitmaks
One of the shoes worn more than others makes me believe that wheel cylinder piston is not working right. Possibly need to rebuild/replace your wheel cylinders. Also replace all the hardware, it's just a few bucks.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: September 21st, 2013, 2:25 pm
by Mx3forever
Thanks for the reply, you could be right. I don't see any other reason I should be having problems with the rear drum fit, outside the fact that the cylinders may have a problem. I noticed this sort of scraping-humming sound before the change. After I changed the pads and had to get the drums on with a hammer, I notice a sort of changing tone scrapping sound. It goes in and out, sometimes disappearing for a moment.

I'm going to disassemble the drums again today, adjust the e-brake and put a C-clamp to the cylinder (although I doubt that would be a problem after the drums got on). I doubt it's the E-brake but I'll go ahead and put just a little more slack in it.

I've looked up the cylinders on Rock Auto and may buy a set if the scrapping continues after today.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: September 21st, 2013, 5:10 pm
by Mx3forever
Actually, I'm putting it off until I get the new cylinders next week, might as well replace them if I'm going through the motions of disassembling everything.
I sure don't want to do this a third time.

Re: Rear Brake Adjustment? Drum doesn't seem to go on

Posted: September 27th, 2013, 7:54 pm
by Mx3forever
Cool, I think I got it fixed.

Got new wheel cylinders from Rock Auto and it is possible that my pad adjusters were a little incorrect.
>HINT< if you put on new pads, push the little notched adjusters all the way toward the car until they will go no further.
That seems to be the tightest pad position.

The new cylinders likely effected the fit as well, but it wasn't hard to get the drums back on this time. They went right back with a little tap from a hammer.

I think the other problem, part of the grinding sound may have come from an inner ring of thin metal on the brake assembly.

You can see this metal ring clearly it in my pictures, it's the metal right inside the outer diameter of the brake, kind of bent up looking.

I'm not sure what it's function actually is but it looks like it was supposed to fit inside a groove of the drum. It was badly rusted and certainly out of spec, possibly grinding on the drum as the drum turned.

I just tore all this corroded metal out of the assembly and polished it up with a drill brush.