[DeTomaso] Replaced rear brake pads, was Re: Porterfield rear brake pads

Guido deTomaso guido_detomaso at prodigy.net
Tue Dec 1 20:08:26 EST 2015



That's kinda interesting.
What I discovered today was, the friction material on my re-lined Porterfield pads was too long.  Not too thick in the wear direction, but too long in the disc circumference direction.  So on the inboard pad, they got wedged in to the caliper body very tight.  Took hammer blows to install, I had to admit to myself those pads would likely stick.
So took them out, very difficult since they were wedged in so tight, sanded the ends down, avoiding sanding the metal backing plates, tried to only sand the friction material.  Once sanded, they dropped in easily.
The stock pads, the friction material is slightly shorter than the metal backing plate ... something to be learned there.
GD
       From: Garth Rodericks <garth_rodericks at yahoo.com>
 To: "guido_detomaso at prodigy.net" <guido_detomaso at prodigy.net>; DeTomaso Mail List <detomaso at poca.com> 
 Sent: Monday, November 30, 2015 11:02 AM
 Subject: Replaced rear brake pads, was Re: Porterfield rear brake pads
   
The problem I had after installing my new Porterfield pads years ago was the caliper pistons on the rear right wheel got stuck in their bores because of all the gunk/varnish that built up in there there over the years - it had been a long time since the pistons were pushed that far back into their bores. Calipers released after a few good whacks with the handle of a screwdriver as well as letting things cool down - don't know which really solved the problem, but they haven't stuck since.


--- Original Message ---Well, yesterday I replaced the rear pads on one side, ran out of daylight before I could do the other side.
Wasn't too difficult, had never tampered with that aspect of the car before, I suspect no one else had either.
Didn't realize / had forgotten that a piston pokes out both sides of the caliper cylinder ... wasn't too difficult to turn the slotted piston 45 deg., but wasn't easy either.  Wound up cutting the blade off a Craftsman square-shank screwdriver to make a "special tool".  Piston retracted easily once turned 45 and with the bleeder open.
The metal frame however, that pushes the outboard pad into the disc, was difficult to slide outboard to accommodate the new, much thicker pad.  Took infinity of dead-blow hammer strikes.
Old pads pretty thin at 75K miles,  I suppose the p-valve is working or did work at one time.
Wondering now how often the seals fail after a pad change, from all the turning and sliding of the piston.  Are rebuild seals and parts still available?
Thanks,
GD

 
-------------- next part --------------
   That's kinda interesting.
   What I discovered today was, the friction material on my re-lined
   Porterfield pads was too long.  Not too thick in the wear direction,
   but too long in the disc circumference direction.  So on the inboard
   pad, they got wedged in to the caliper body very tight.  Took hammer
   blows to install, I had to admit to myself those pads would likely
   stick.
   So took them out, very difficult since they were wedged in so tight,
   sanded the ends down, avoiding sanding the metal backing plates, tried
   to only sand the friction material.  Once sanded, they dropped in
   easily.
   The stock pads, the friction material is slightly shorter than the
   metal backing plate ... something to be learned there.
   GD
     __________________________________________________________________

   From: Garth Rodericks <garth_rodericks at yahoo.com>
   To: "guido_detomaso at prodigy.net" <guido_detomaso at prodigy.net>; DeTomaso
   Mail List <detomaso at poca.com>
   Sent: Monday, November 30, 2015 11:02 AM
   Subject: Replaced rear brake pads, was Re: Porterfield rear brake pads
   The problem I had after installing my new Porterfield pads years ago
   was the caliper pistons on the rear right wheel got stuck in their
   bores because of all the gunk/varnish that built up in there there over
   the years - it had been a long time since the pistons were pushed that
   far back into their bores. Calipers released after a few good whacks
   with the handle of a screwdriver as well as letting things cool down -
   don't know which really solved the problem, but they haven't stuck
   since.
   --- Original Message ---
Well, yesterday I replaced the rear pads on one side, ran out of daylight before
 I could do the other side.
Wasn't too difficult, had never tampered with that aspect of the car before, I s
uspect no one else had either.
Didn't realize / had forgotten that a piston pokes out both sides of the caliper
 cylinder ... wasn't too difficult to turn the slotted piston 45 deg., but wasn'
t easy either.  Wound up cutting the blade off a Craftsman square-shank screwdri
ver to make a "special tool".  Piston retracted easily once turned 45 and with t
he bleeder open.
The metal frame however, that pushes the outboard pad into the disc, was difficu
lt to slide outboard to accommodate the new, much thicker pad.  Took infinity of
 dead-blow hammer strikes.
Old pads pretty thin at 75K miles,  I suppose the p-valve is working or did work
 at one time.
Wondering now how often the seals fail after a pad change, from all the turning
and sliding of the piston.  Are rebuild seals and parts still available?
Thanks,
GD


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