[Shotimes] Dragging rear pads when e-brake is released
Tom Leeth
tomleeth@charter.net
Fri, 5 Dec 2003 21:29:51 -0600
----- Original Message -----
From: Tom Leeth
To: Mike.Wojton@us.o-i.com
Sent: Friday, December 05, 2003 9:21 PM
Subject: Dragging rear pads when e-brake is released
Mike, I chased this problem for several years, replacing calipers first,
rotors next, brake lines next, disconnecting e-brake cables next, re-lubing
slider pins next, changing caliper brackets next, re-adjusting push rod length
on proportioning valve next, and finally replacing the proportioning valve
itself. Everything I did seemed to help for a few days than the pads would
start dragging again after the e-brake was released - especially at first
motion in reverse.
I finally tied the proportioning valve push rod in the full-up position using
nylon cable ties and stopped setting the e-brake when the car is in the garage
(and is going to sit overnight). I still (sometimes) get a very slight drag
during slow 90 degree turns when the brakes are hot, but after 15,000 miles I
have had no dragging at first motion and under all conditions the problem is
about 98% solved.
I think that on some SHO's there is a problem with the proportioning valve
not properly releasing pressure on the rear calipers. At some point I plan to
put the plugs in the proportioning valve body but haven't yet. The cable tie
trick is easy, free (maybe 15 cents for ties), and its easy to do a function
check on the e-brake with the rear wheels off the ground. After you tie the
push rod up in the fully compressed position, the rear wheels should rotate
freely with the rear of the car off the ground, both before the e-brake is
applied and after it is released.
Give it a shot.
Regards,
Tom Leeth
'93 Silver ATX with 96,000 one-owner miles
P.S. Make sure your ABS is working before you do this, otherwise it might be
dangerous under emergency conditions (rear wheels locking up too soon relative
to front wheels).