1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Rear Disc Rotor Woes!! Help!

Thread Tools
 
Search this Thread
 
Old 10-20-04, 12:35 AM
  #1  
Full Member

Thread Starter
 
RUBY7's Avatar
 
Join Date: Jul 2004
Location: Australia
Posts: 189
Likes: 0
Received 0 Likes on 0 Posts
Rear Disc Rotor Woes!! Help!

Iam almost at the end of my rope with these moaning and groaning rear disc brakes.

I have over the last 2 years or so (since this trouble began) replaced pads numerous times, installed new rotors, rebuilt the calipers, replaced the shims. all to no avail.

Can someone please help, the only thing (and this maybe a clue) that has helped has been machining the discs, Although this only lasts a coupla months.

Cheers Sue
Old 10-20-04, 12:53 AM
  #2  
Lives on the Forum

 
Kentetsu's Avatar
 
Join Date: Jun 2004
Location: Grand Rapids Michigan
Posts: 11,359
Received 14 Likes on 11 Posts
A few questions for you:

1. Is there any chance that something might be bent back there? This may cause uneven wear.

2. You said that machining the rotors helped for a bit. Have you looked at them lately? See if there is any scoring present, and that may help track down the root of the problem.

3. Do the brakes seem to drag at all?

4. Do the wheels feel hot after driving on the highway for a while? (sign of dragging brakes).

That's all I can think of. Answers to these questions may shake something loose though. Good luck!
Old 10-20-04, 01:01 AM
  #3  
Full Member

Thread Starter
 
RUBY7's Avatar
 
Join Date: Jul 2004
Location: Australia
Posts: 189
Likes: 0
Received 0 Likes on 0 Posts
Thanks for the quick reply and suggestions.

Doubt very much if something is bent back there, problem started after owning the car for a year or so.

Yeah, brand new outa the box rotors. (seems I replaced perfectly good ones)

Don't know if the brakes are draging at all, you say the wheels themselves would be hot?

Thanks Sue
Old 10-20-04, 01:10 AM
  #4  
Lives on the Forum

 
Kentetsu's Avatar
 
Join Date: Jun 2004
Location: Grand Rapids Michigan
Posts: 11,359
Received 14 Likes on 11 Posts
Yeah, if they're dragging bad enough they will heat up the wheel (don't ask how I know this!).

Would still like to know if there has been any unusual wear on your rotors though...
Old 10-20-04, 01:21 AM
  #5  
Full Member

Thread Starter
 
RUBY7's Avatar
 
Join Date: Jul 2004
Location: Australia
Posts: 189
Likes: 0
Received 0 Likes on 0 Posts
The rotors haven't been in long enough I dont think, there is some glazing however, no ware that I can make out. Remove the glazing be it by bita sandpapaer or machining and moaning is gone till they glaze up again.

This experience is over the two sets of rotors, the new ones have only been in a month or so and are moaning now.

Wet days like today are unbearable.

Iam at a loss.
Old 10-20-04, 02:23 AM
  #6  
Old Fart Young at Heart

iTrader: (6)
 
trochoid's Avatar
 
Join Date: Apr 2004
Location: St Joe MO
Posts: 15,145
Likes: 0
Received 7 Likes on 7 Posts
Couple of questions.

Have you done anything with the front brakes? Are they working properly? Are they weaker than they used to be.

Do your brake pads match front and rear? Same brand and compund.

Have you flushed the entire brake system?

Are the caliper pins shiny and do they move freely? Are you lubeing the pins?

Are the pads wearing evenly between the inners and outers?

How's the master cylinder? Has it been replaced? If so were lines to the proportioning valve connected correctly?

Replacement pads will glaze if used too hard when new. They ususally need some break in.
Old 10-20-04, 02:24 AM
  #7  
Old Fart Young at Heart

iTrader: (6)
 
trochoid's Avatar
 
Join Date: Apr 2004
Location: St Joe MO
Posts: 15,145
Likes: 0
Received 7 Likes on 7 Posts
Sorry, that was more than a couple of questions.
Old 10-20-04, 07:06 AM
  #8  
0000-09-0233

 
SS124A's Avatar
 
Join Date: Jun 2003
Location: Fort Wankel
Posts: 1,317
Likes: 0
Received 0 Likes on 0 Posts
when replacing your pads, did your new calipers have the retaining springs? If so, did you use them?
Old 10-20-04, 08:29 AM
  #9  
Right near Malloy

iTrader: (28)
 
Pele's Avatar
 
Join Date: Dec 1999
Location: Behind a workbench, repairing FC Electronics.
Posts: 7,841
Received 510 Likes on 345 Posts
1.) Remove rotor. Coat Hub where it contacts rotor in a thin layer of grease.

2.) Coat backs of pads where they contact the caliper and piston with grease.

3.) Coat area where wheel contacts rotor with grease.

DO NOT GET GREASE ON THE FRICTION SURFACE OF THE ROTOR OR PADS.

THis solves 90% of brake problems... When you rub two materials together as brakes do, you're bound to get some vibration, it's inevit inevitable... INEVITABLE! It's reverberation through the car's chassis causes it to be louder. The grease dampens the vibration
Old 10-20-04, 06:03 PM
  #10  
Senior Member

 
Jon_Valjean's Avatar
 
Join Date: Apr 2002
Location: Napier
Posts: 476
Received 41 Likes on 24 Posts
You may have a bent axle or worn wheel bearing that is causing movement in the brake assembly?
Old 10-20-04, 06:57 PM
  #11  
Full Member

Thread Starter
 
RUBY7's Avatar
 
Join Date: Jul 2004
Location: Australia
Posts: 189
Likes: 0
Received 0 Likes on 0 Posts
Thanks all for your help.

Trochoid,
Front brakes seem to work fine.
Dont think front and back do match, but will after today. The sydstem has been fully flushed a number of times. Brake blokes are having the car this arvo so I will get them to check the caliper pins. Finally, yes new master cylinder.

Waapst
Retaining spring, if you mean shims, the flat thin metal whosits, then yes.

Pele
This will be done today.

Jon
It would surprise me greatly if anything on the back of the car were bent.

Thanks again for your imput


Cheers Sue
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Marty RE
New Member RX-7 Technical
0
08-13-15 11:19 AM



Quick Reply: Rear Disc Rotor Woes!! Help!



All times are GMT -5. The time now is 08:20 PM.