Big Red problems!!!

[onixbonilla]

Hi everyone!
My 1303 uses front and rear 993 Big Reds with a 951 master unit. I had discover a very disturbing situation. The car brakes very well but the pads do not retract and mantain constant preasure on the rotors.When you jack the car, in order to rotate the wheels I have to push them fairly hard.
In fact when I drive it slowly and depress the clucth it stops by himself,I can feel the brakes working.
Previously I had the 951 calipers/rotors and have no problem, they turn easily.
The following are some things that I had try but no success yet;
-centralize better the caliper using different washers
-installed some used pads(half the width of the new ones) but once the pads
move farther and touch the rotors they do not retract and mantain constant pressure
Rechecked the pedal assambly brake pushrod, it have completelly free movement
As stated before the master unit is the same 951 used with the 951 brakes with no problem at all.
Anyone had similar problems?
Any ideas?
Thanks
Onix

[Sandeep]

Does your pedal return back to normal height after you apply the brakes ? What are the condition of the calipers ? New or used/cleaned ?

Have you made sure the brakes are properly bled with no air in the system ?

I noticed the same problem with my setup (993 TT front and 944T front on rear) when I first started driving my car and after a re-bleed ... the problem went away.

Sandeep

[onixbonilla]

The brake pedal does return to the normal position.
The calipers are used from LA dismantlers.
We bleed the brakes twice.
Yesterday I disassembly one front caliper(to my sorry) found nothing wrong, just ended with 4 piston that are nearly impossible to place back and a totally scracthed caliper.
Thanks
Onix

[onixbonilla]

I wonder if this had to be to the fact that these brakes were desingned for cars equipped with brake boosters. Do the brake boosters cause retraction of the pistons?
Onix

[volkdent]

I'm sorry to hear you guys are having troubles, but I'm glad you're discussing it here so we can all learn something hopefully.

Jason

[zen]

i have 951 m/c and calipers all around. i have not experienced this. i have the new pads touching a little, but all seem to retract fine. just have to break-in the first mm.

i have had an issue with the brake pedal pushrod not being long enough since my m/c piston seems to sit a little more forward than the stock unit.