[DeTomaso] Replacing Rear Brake Pads - what am I missing

[MikeLDrew at aol.com]

In a message dated 11/18/17 13 33 37, mbefthomas at comcast.net writes:


Tring to install the new rear brake pads (been 10 years since I've done
this).   I used a C-clamp to move the sliding cylinder back as far as it 
will
go.   Now I'm trying to compress the piston, but it won't move.   I have 
the
cover off of the master cylinder to allow fluid to flow back.   I've tried
using a large pair of channel lock pliars and the C-clamp to get the piston
to compress.   Is there something else I need to release or is the cylinder
just stuck?   Brakes were working OK at the end of the season.


>>>AAACCCKKK!!!!!

I'm so glad you put down the tools of destruction and fired up your 
computer!   The process you were following is how many people have destroyed their 
rear calipers!

The parking brake system uses an internal magical ratcheting system that I 
confess I have never understood.   However, the shop manual addresses it 
clearly--there is a slot machined into the piston.   A screwdriver or suitable 
lever needs to be inserted into this slot and the piston needs to be rotated 
exactly 45 degrees to disengage the parking brake system, before the piston 
can be compressed.   Once it's fully compressed, the piston needs to be 
rotated back to its original orientation.

Asa Jay has fantastic photos of the exploded rear calipers here:

http://www.teampanteraracing.com/gallery2/v/asajay/pantera/brakes/rearbrakes
/

The process is explained in detail on page 12-11-01 of the shop manual, 
complete with diagrams and photos.   Read and heed!

Also, what is left unmentioned is that the stock rear pads have a small tab 
on the back side, which is designed to engage the slot in the piston and 
keep it from rotating.   Some aftermarket pads are lacking this tab.   
Porterfield will supply it, and should do so automatically, but sometimes they have 
to be specifically reminded or else they will deliver them without them.   
The Porterfield pad sets I've seen have included two pads with tabs, and 
those are the ones that face the caliper pistons.

Good luck!

And if anybody cares to explain to me (type slowly and use small words) 
EXACTLY how this whole ratcheting parking brake system works, I would be most 
appreciative!   Thanks!

Mike
-------------- next part --------------
   In a message dated 11/18/17 13 33 37, mbefthomas at comcast.net writes:
   Tring to install the new rear brake pads (been 10 years since I've done
   this).  I used a C-clamp to move the sliding cylinder back as far as it
   will
   go.  Now I'm trying to compress the piston, but it won't move.  I have
   the
   cover off of the master cylinder to allow fluid to flow back.  I've
   tried
   using a large pair of channel lock pliars and the C-clamp to get the
   piston
   to compress.  Is there something else I need to release or is the
   cylinder
   just stuck?  Brakes were working OK at the end of the season.
   >>>AAACCCKKK!!!!!
   I'm so glad you put down the tools of destruction and fired up your
   computer!  The process you were following is how many people have
   destroyed their rear calipers!
   The parking brake system uses an internal magical ratcheting system
   that I confess I have never understood.  However, the shop manual
   addresses it clearly--there is a slot machined into the piston.  A
   screwdriver or suitable lever needs to be inserted into this slot and
   the piston needs to be rotated exactly 45 degrees to disengage the
   parking brake system, before the piston can be compressed.  Once it's
   fully compressed, the piston needs to be rotated back to its original
   orientation.
   Asa Jay has fantastic photos of the exploded rear calipers here:
   http://www.teampanteraracing.com/gallery2/v/asajay/pantera/brakes/rearb
   rakes/
   The process is explained in detail on page 12-11-01 of the shop manual,
   complete with diagrams and photos.  Read and heed!
   Also, what is left unmentioned is that the stock rear pads have a small
   tab on the back side, which is designed to engage the slot in the
   piston and keep it from rotating.  Some aftermarket pads are lacking
   this tab.  Porterfield will supply it, and should do so automatically,
   but sometimes they have to be specifically reminded or else they will
   deliver them without them.  The Porterfield pad sets I've seen have
   included two pads with tabs, and those are the ones that face the
   caliper pistons.
   Good luck!
   And if anybody cares to explain to me (type slowly and use small words)
   EXACTLY how this whole ratcheting parking brake system works, I would
   be most appreciative!  Thanks!
   Mike