[200q20v] Rear Caliper sticking?

[Peter Schulz]

At 12:16 PM 10/14/00 -0400, Kneale Brownson wrote:
>I found that manually retracting the lever,  soaking it with penetrating 
>oil repeatedly and even totally disengaging the e-brake cable would not 
>stop the brake from dragging.  I think the internal brake actuating 
>fixtures remain stuck once they're sufficiently corroded.  I even turned 
>the pistons back in after disconnecting the cables, and the brakes 
>returned to binding against the rotors within a couple applications of the 
>brake pedal.


JJ, Kneale, et al...

BTDT on both my 1990 CQ and the 200...what has happened is that shaft of 
the parking brake cam has corroded...On the 200, I gave up after being 
trying the method repeatedly, and not regaining full operation - the good 
news is that you can call Mack at Clair Parts Connection, and get a pair of 
rear rebuilt calipers with pads for about $200, with core exchange....

HTH

Peter Schulz
1990 CQ
1991 200 20v TQW
Chelmsford, MA USA
peschulz at cisco.com

from Chris' web page: http://members.aol.com/c1j1miller/index.html


Rear brakes

This weekend Peter Schulz showed me how to conduct periodic maintenance on
the one of the rear calipers on my 200q20v.  The car had the typical
symptoms; braking seemed diminished; sticking rear parking brake.
Chock, jack, block, remove a rear wheel.  Remove guide pins, clean, inspect
boots over guide pins.  One of my guide pins was seized, as the rubber boot
had torn; cleaning and lubing restored it.  Next year, new guide pins all
around.

Once the pins are removed, pull the floating caliper free, and hang it with a
wire or bungee for strain relief on the rubber brake line.  Use the caliper
tool to turn the face of the caliper back in a ways.  Remove the parking
brake return spring, then remove the retaining bolt for that spring.  Pry the
parking brake lever down away from the caliper, and clean the shaft.  I used
some very fine emery paper to remove corrosion, sprayed with brake cleaner,
then lubed it with a brake grease.  Push the shaft back in place, reinstall
the spring and retaining bolt.

Pull the two pads off the caliper frame, and clean their mounting areas.  One
of my pads was frozen in place.  I cleaned the sliding portion of the backing
plate with a file, and scraped the corresponding area on the caliper.  Put
the pads back, making sure the inner pad goes back on the inside...

Put the caliper back in place, put loctite on the guide pin retaining bolts,
and torque them back up.  Pump the brakes a bit to reseat the caliper/pads.
Reinstall the wheel, torque up the bolts, lower and unblock car, then clean
up.

Probably an annual chore.

chris


 From the 20v Web page: http://20v.org/20v/brakprob.htm#handbrake


Inoperative Handbrake
(Peter Schulz)
An inoperative or weak handbrake can be a disastrous thing. It might just 
need to be adjusted, but a common problem problem is the cams on the rear 
calipers
get frozen with rust. To check/fix the operation of the cams:

    1.Handbrake off, car in gear, front wheel blocked by a wheel chock, 
rear end lifted SECURELY by jackstands.
    2.Under the car, follow the handbrake cable to the rear calipers--they 
attach to a cam which also has a circular spring held in place by a slot in 
the cam
      and a 10mm bolt. The cam is attached to a shaft internal to the 
caliper. This shaft, in turn, applies mechanical pressure on the rear 
caliper piston.
    3.That shaft is not protected externally by a boot and tends to collect 
rust. The rust prevents the spring from tensioning the cam, which in turn 
gives little or
      no feedback to the handbrake--hence the "out of adjustment" feel.
    4.Carefully compress the spring and removed it, then pull the handbrake 
brake cable out of the cam slot. If the cam is difficult to move back and 
forth,
      then you've found your problem.
    5.Liberally spray lubricant/rust remover around the cam shaft and work 
the cam back and forth to it's limit stops repeatedly. Let the lubricant 
soak in for a
      while, then repeat several times. The cam should now move easily, 
allowing the spring to apply tension and feedback to the handbrake.
    6.If the cam is badly rusted, you can try taking it all the way out to 
clean it up. You'll have to remove the piston from the caliper first, 
though. If refuses to
      move, you'll have to get new calipers.
    7.When you feel like the cams are freed up, apply some brake grease to 
the exposed part of the cam shaft, then put it all back together.
    8.It is rumored that stronger springs from some Ford model will help 
keep this problem from happening. The Ford P/Ns are: 6141147 & 6141148.



Peter C. Schulz				peschulz at cisco.com
Quality Systems Engineer/SSE		http://www.cisco.com
Customer Contact Business Unit (CCBU)	Direct: 978.275.7772
Cisco Systems, Inc. 			Fax: 	978.275.5299
900 Chelmsford Street 			Pager: 	800.365.4578
Lowell, MA 01851 USA