Pressure bleeding master cylinder?
Thread Starter
Racer
Joined: Feb 2005
Posts: 332
Likes: 22
From: Georgia
Pressure bleeding master cylinder?
After swapping out calipers for a full set of powder coated ones from TPS Motorsports (they look GREAT, btw), I'm having trouble getting a hard pedal. Not being picky, it's really not right. Master cylinder ran dry while calipers were off the car so I bench bled the master cylinder after doing a full four corner bleed with speed bleeders, followed by a second full four corner bleed after bench bleed. With little improvement in the pedal at all, I figured it was air in the ABS system so I took it to my mechanic and we did a pressure bleed with his scan tool and BG bleeder. Still poor pedal feel with little improvement, we followed with a manual bleed at the calipers. Still no good. Question is, if by chance I didn't evacuate the air properly on the bench bleed, would the pressure bleed have pushed any remaining air out of the master and into the lines where it should have been bled out in the subsequent multiple bleeds? My mechanic thinks its a bad master cylinder. I'd like to rule out other problems before I pull the trigger and buy a new master. Any thoughts?
Burning Brakes
Joined: Jul 2011
Posts: 1,100
Likes: 112
From: Fredericksburg Virginia
I has similar issue so I followed what service manual said. Bought the fittings that fit master cylinder and put line through them and then used hammer and vice to crimp them over twice. I actually disassembled MC and cleaned it first. Then I installed MC in vice and put home made plugs (fittings with line) and started bleeding. Kept tilting MC forward and then back until no air was coming out. At that point I could only push about 1/16 in before it was hard. Then reinstalled and had son push pedal when I reconnected each line to push air out. Worked like a charm. Brakes are solid now.
Chris
Chris
Thread Starter
Racer
Joined: Feb 2005
Posts: 332
Likes: 22
From: Georgia
No, I definitely did not install just one caliper upside down. I installed TWO calipers upside down. I AM WE TODD DID. I AM SOFA KING WE TODD DID. Read that aloud several times and you'll know how I feel. At least I'm not the first and I feel better that even my mechanic also overlooked what we both know is wrong.
