Page 1 of 2

rear brakes squealing (like a pig)

Posted: Mon Sep 29, 2008 11:35 am
by Ritter
I had some fun driving on the Sonoma Coast Highway 1 this weekend. Lots of 2nd and 3rd gear adventures. Oh and did I mention my rear brakes were deafening?:oops:

In another thread, Colin said:
Amskeptic wrote:Rear brake warm squeaks are usually a hard glaze and shoes not properly chamfered at the leading edges.
I've got some brake pedal pulse that would suggest glazing. Now, if I pull the drums and sand at 45 each way to remove the hard glaze, will I need new shoes as well (they probably have less than 1000 miles on them)?

Please elaborate on the "chamfered" leading edge.

Posted: Mon Oct 13, 2008 8:20 am
by Ritter
Well, I pulled the drums and sanded 45* both directions a few times each. Cleaned. Cleaned shoes. Put a ~45* bevel on the leading edges of the shoes. Cleaned shoes. Reassembled. Adjusted brakes. Drove and bedded shoes with two hard stops (did not stop rolling) at 35, 45 and 50.

Still squealing like stuck pigs after they get hot. Ideas? What am I doing wrong? Shitty shoes? Help!

Posted: Mon Oct 13, 2008 8:35 am
by hambone
My fronts squeal. I've learned to ignore them.
This MAY work for you!
:drunken:

Posted: Mon Oct 13, 2008 9:53 am
by Sluggo
Here's something stupid that I did. Did you reinstall the brake backing plates? Without them you get the worst squeal. Extremely loud.

Posted: Mon Oct 13, 2008 1:08 pm
by chitwnvw
What year, Ritter?

See my thread about brakes, I learned a thing or two from Bretski.

Posted: Mon Oct 13, 2008 1:59 pm
by bus71
Did you sand the shoes also? Make sure that the retaining pins and springs are in place. You need to sand the drums so there are no shiny spots. I don't recomend any hard stops till about 500 miles. Good luck!

Posted: Mon Oct 13, 2008 2:06 pm
by Ritter
chitwnvw wrote:What year, Ritter?

See my thread about brakes, I learned a thing or two from Bretski.
1978 (see sig line!)

Yeah, I've read that thread, but my problem is in the rear. I'm sure I'll reread it when I work on the fronts.

Posted: Mon Oct 13, 2008 2:10 pm
by Ritter
bus71 wrote:Did you sand the shoes also?
No, I did not sand the shoes. I guess I should have?
bus71 wrote:Make sure that the retaining pins and springs are in place.
The little pins that should go through the backing plate, then the shoe and then get topped with a spring and shinny disk thing? I'd love to but can't seem to find any corresponding hole in the backing plate. Is this a bunk part or a year-specific omission?
bus71 wrote:You need to sand the drums so there are no shiny spots. I don't recomend any hard stops till about 500 miles. Good luck!
I did do this. Oops on the hard stops. So no bedding of the shoes?

Posted: Mon Oct 13, 2008 2:31 pm
by bus71
The pins may only be on older buses, don't know for sure. Sand the shoes also, then champher. There are differences of opinion on the hard stop. I was taught to avoid them on new brakes. This is what we told our customers. :profileleft:

Posted: Mon Oct 13, 2008 4:55 pm
by Amskeptic
Sorry I am late. You have to have to have to sand the linings at the same time you sand the drums. You do not have the retainer spring/pins of the earlier higher quality buses. Are your linings a consistent thickness around the circumference of the shoe webs? Sometimes a bad ebrake-left-on wear pattern will not respond to your chamfering. Also, keep your adjustment a little loose here while trying to figure out the squealing. You need both full release with the footbrakes and the ebrake and strong return springs correctly installed, i.e. the upper spring has to be behind the shoe web.

If it comes back, I am guessing dragging shoes.
Colin

Posted: Mon Oct 13, 2008 5:13 pm
by Sluggo
Sluggo wrote:Here's something stupid that I did. Did you reinstall the brake backing plates? Without them you get the worst squeal. Extremely loud.
Nevermind. I answered when I had just woke up. Realized on the way to work that you were talking about rear drums not front disks.

Posted: Mon Oct 13, 2008 6:51 pm
by Ritter
Sluggo wrote:
Sluggo wrote:Here's something stupid that I did. Did you reinstall the brake backing plates? Without them you get the worst squeal. Extremely loud.
Nevermind. I answered when I had just woke up. Realized on the way to work that you were talking about rear drums not front disks.
No worries. Thanks for thinking of me on the way to work though! =D>

Posted: Mon Oct 13, 2008 6:52 pm
by Ritter
Amskeptic wrote:Sorry I am late. You have to have to have to sand the linings at the same time you sand the drums. You do not have the retainer spring/pins of the earlier higher quality buses. Are your linings a consistent thickness around the circumference of the shoe webs? Sometimes a bad ebrake-left-on wear pattern will not respond to your chamfering. Also, keep your adjustment a little loose here while trying to figure out the squealing. You need both full release with the footbrakes and the ebrake and strong return springs correctly installed, i.e. the upper spring has to be behind the shoe web.

If it comes back, I am guessing dragging shoes.
Colin
I will try the next opportunity I get (probably 2 weekends...)

Posted: Mon Oct 13, 2008 8:23 pm
by chitwnvw
Ritter wrote: I will try the next opportunity I get (probably 2 weekends...)
Chop, chop!

Posted: Mon Oct 13, 2008 8:28 pm
by karl
If you are going to replace the shoes...... you might consider converting to Vanagon self-adjusting rear brakes. Saves having to adjust the bay shoes all the time..... http://www.type2.com/library/brakes/selfadjust.htm