Soft pedal after upgrade
Thread Starter
Le Mans Master
Joined: Jul 2009
Posts: 6,381
Likes: 66
From: SF bay area C.A.
C4 of the Year Finalist
Soft pedal after upgrade
Ok guys & gals finished up my J55 upgrade and have a softer pedal than before. Had a hard pedal before which may have been too stiff but it stopped great. What was done-- j55 calipers, carbotech ax6 pads front and rear and bled all 4 brakes until I had a complete fluid change. It stops fantastic but the pedal is much easier to push and grabs lower. Thank's all
Safety Car
Joined: Nov 2009
Posts: 3,973
Likes: 341
From: Adelaide South Australia
What is the difference in the caliper piston size ?
If you have larger diameter caliper pistons you have to move more brake fluid.
have a read of this,
http://www.cheapsportscar.net/hydraulics.php
If you have larger diameter caliper pistons you have to move more brake fluid.
have a read of this,
http://www.cheapsportscar.net/hydraulics.php
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Not sure about the differences in the J55 caliper and the C5 caliper in terms of piston volume, but when I put C5 front brakes on my '87, I didn't see much of a difference at all with pedal pressure or pedal travel.
What I did do was to install the Doug Rippie brake bias spring in the master cylinder.
Could there be a difference in the master cylinder itself between the stock brakes and the J55?
What I did do was to install the Doug Rippie brake bias spring in the master cylinder.
Could there be a difference in the master cylinder itself between the stock brakes and the J55?
Thread Starter
Le Mans Master
Joined: Jul 2009
Posts: 6,381
Likes: 66
From: SF bay area C.A.
C4 of the Year Finalist
Udate
Ok my neighbor is a young guy and a rookie mechanic so first I'll say letting him work on the car was my mistake. I had the j55 upgrade about done when I needed to make an errand, my neighbor [lets call him ted] asked if he could finish up by putting on the calipers and bleeding them[ have speed bleeders] so ok go for it. I finally got a chance to check things out and re bleed the system when I found the problem instantly. Now I could tell you or make it a little fun so fun it is. What was the problem? 
Btw the system works like a charm but now I need to chase down why my shift lights not working.
Btw the system works like a charm but now I need to chase down why my shift lights not working.
Last edited by kimmer; Mar 30, 2014 at 03:32 PM.
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Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 78
From: Monroe OH
NCM Sinkhole Donor
My pedal is very easy to push, but I contribute that to the high vacuum and a good booster.
I guess the only benefit to the calipers on the wrong side would be the bleeding would be relatively easy. That makes the bleeder point to the ground correct?
I guess the only benefit to the calipers on the wrong side would be the bleeding would be relatively easy. That makes the bleeder point to the ground correct?
Pro
Joined: Aug 2012
Posts: 663
Likes: 1
From: Nashville TN
With the bleeders pointing up the air naturally moves toward the bleeder. They nearly bleed themselves. The rears require about 200 cycles.
Thread Starter
Le Mans Master
Joined: Jul 2009
Posts: 6,381
Likes: 66
From: SF bay area C.A.
C4 of the Year Finalist
With the bleeders facing down you can never get all the air out thus soft low catching pedal which you can always pump to stiffen. My pedal is better now than it has ever been.
Last edited by kimmer; Mar 30, 2014 at 08:22 PM.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
Kimmer;
The J55 calipers have the same pistons and rebuild kit as the 12" original system. They use the same size pads also.
Did you know there is a left and right rotor. They are directional. Why, the fins are curved for airflow for better cooling.
I like my J55s also.
The rotor is bigger and so is the price.
