RE: UFO Brakes

[Peter Henriksen <peterhe@microsoft.com>]

Thanks for all the info, Paul.

I think I'll add this to the 91 200 and V8 general sections in the spec
project if you don't mind.
- peter
  peterhe@microsoft.com - http://www.geocities.com/MotorCity/1001
  91 200qw
  94 acura legend gs
  issaquah, wa, usa


>-----Original Message-----
>From:	Paul C. Waterloo [SMTP:74543.407@CompuServe.COM]
>Sent:	Thursday, November 21, 1996 4:51 PM
>To:	Peter Henriksen; "'alexneckas@aol.com'"; "'gregsj@minimall.imm.co; Eric
>Harman; INTERNET:quattro@coimbra; Lorens Kulla; John Mallick; Mike Miller;
>Arun Rao; Major Schutt; Sal Stabile; Frank Stadmeyer; David Toppin; Linus
>Toy; Stephen Williams; Joe Yakubik
>Subject:	UFO Brakes
>
>After the recent discussions about UFO's, I looked them up in the Bently for
>the
>first time. Couple interesting things to report:
>
>Brake Caliper - the outline drawing says "cannot be repaired, replace if
>necessary"...that seems kinda weird, you can't overhaul them? Anybody ever
>try?
>
>There is a section on "Steering Wheel Shimmy During Braking", it has three
>things you can do to fix it (they are outlined in this order):
>
>CHECK CONTROL ARM BUSHINGS
>1. Remove wheels, disconnect brake pad sensors, remove front pads, remove
>calipers, but do not disconnect.
>
>2. If you have less than 40K on your car, inspect the inner and outer control
>arm bushings for cracking, splitting and deterioration.
>
>3. Replace as necessary.
>
>4. If you have more than 40K on your car, replace both front inner and outer
>front control arm bushings. For those who don't know what a control arm
>bushing
>is, it's the bar that the front sway bar and lower ball joint are attached
>to.
>The bushings that they are talking about are where the sway bar goes through
>the
>control arm, and where the control arm attaches to the subframe (I think
>subframe is the correct term) of the car.
>
>TRUING OF FRONT BRAKE ROTORS
>
>1. True front brake rotors with an on-the-car brake lathe.
>
>2. Note: if an on-the-car brake lathe is not available, replace rotors.
>
>3. FYI - brake disc thickness new 25 mm (0.750"), brake disc wear thickness -
>23mm (0.690")
>
>WHEN NEW BRAKE ROTORS ARE REQUIRED
>
>1. Thoroughly clean contact surfaces of brake rotor and hub.
>
>2. Install using all lug bolts with suitable spacers.
>
>3. Tighten lug bolts diagonally in stages to 29 lb-ft.
>
>4. Attach dial indicator to measure brake rotor runout.
>
>5. Rotate rotor and record runout.
>
>6. Remove brake rotor and remount after rotating rotor to next lug bolt hole.
>
>7. Check rotor runout.
>
>8. Continue remounting rotor checking runout at each lug bolt position.
>        ---- Maximum rotor runout 0.06mm (0.002")
>
>9. Mount rotor in position where lowest runout was achieved.
>
>10. Mark hub and rotor with center punch as mounted in lowest running
>position.
>
>MORALE OF THE STORY
>
>From what I can see, if you car has front end shimmy, I would first check
>brake
>rotor runout and determine what it is, maximum new is 0.002", I wouldn't want
>to
>go past 0.004" or maybe 0.006"?
>
>If rotor runout is acceptable, go after your bushings. If you are going to go
>in
>and do a brake job, why not replace the bushings as a matter of good
>maintenance
>practices. I doubt they cost very much, especially when comparing them to the
>price of rotors and pads.
>
>This procedure will help you determine the root cause of the problem so you
>can
>then fix it!
>
>Paul
>
>*********************************************
>Paul Waterloo
>Colchester, CT
>
>91 200q
>
>EMAIL: 74543.407@compuserve.com
>*********************************************
>