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

Mike & Elizabeth Thomas mbefthomas at comcast.net
Sat Nov 18 18:09:53 EST 2017


45 degrees, that makes sense as I rotated 90 and it won't move, so back to
45.  At least it moves easily enough, just have to find the "slot".  Did
have to send the Porterfields back as even after assurances they sent four
pads without pins, had to send them back for the two with.  Done for today,
will try it again tomorrow.

 

Thanks again.

Mike Thomas

Pres., Panteras Northwest

206-795-3302

Yellow '74 #6328

www.panterasnorthwest.com <http://www.panterasnorthwest.com/> 

 

 

 

From: MikeLDrew at aol.com [mailto:MikeLDrew at aol.com] 
Sent: Saturday, November 18, 2017 2:01 PM
To: mbefthomas at comcast.net; detomaso at server.detomasolist.com
Subject: Re: [DeTomaso] Replacing Rear Brake Pads - what am I missing

 


In a message dated 11/18/17 13 33 37, mbefthomas at comcast.net
<mailto: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 --------------
   45 degrees, that makes sense as I rotated 90 and it won't move, so back
   to 45.  At least it moves easily enough, just have to find the "slot".
   Did have to send the Porterfields back as even after assurances they
   sent four pads without pins, had to send them back for the two with.
   Done for today, will try it again tomorrow.


   Thanks again.

   Mike Thomas

   Pres., Panteras Northwest

   206-795-3302

   Yellow '74 #6328

   [1]www.panterasnorthwest.com




   From: MikeLDrew at aol.com [mailto:MikeLDrew at aol.com]
   Sent: Saturday, November 18, 2017 2:01 PM
   To: mbefthomas at comcast.net; detomaso at server.detomasolist.com
   Subject: Re: [DeTomaso] Replacing Rear Brake Pads - what am I missing


   In a message dated 11/18/17 13 33 37, [2]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:
   [3]http://www.teampanteraracing.com/gallery2/v/asajay/pantera/brakes/re
   arbrakes/
   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

References

   1. http://www.panterasnorthwest.com/
   2. mailto:mbefthomas at comcast.net
   3. http://www.teampanteraracing.com/gallery2/v/asajay/pantera/brakes/rearbrakes/


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