I recently needed to replace my passenger.

JF781981

MEMBER
2001 SATURN SL1
206,000 MILES

I recently needed to replace my passenger caliper. I decided to do both sides so I now have new calipers rotors and pads. Upon completing the job, I have no pressure, (ZERO). I tried rebleeding and then decided my master cylinder must have gone out like I have seen before. I replaced the master cylinder and still zero pressure. Everything has been bled several times, no leaks, yet even if the car is off the pedal does not get completely firm. When car is on pedal goes all the way to the floor. My brake light is not on but I know it works because when I start the car it comes on briefly. I thought when master cylinders were bad that would be a reason to cause that light to start also. Either way I had great brake pressure before replacing the calipers and now nothing at all. These are things I have replaced before so I know how to bleed them correctly. I am confused. Any ideas? Thanks

7 Replies

DRCRANKNWRENCH

MECHANIC
3,380 POSTS

Sometimes it is hard to get fluid moving when large quantities are removed from the system. It is especially hard to get a master cylinder started moving fluid. There are 2 tricks that may help. One is to bleed the brakes in a pattern where you bleed the farthest caliper from the master sylinder and work towards the closest caliper to the master cylinder. This means start at the passenger rear, then driver rear, then passenger front and then driver front. To "Bench Bleed" a mster cylinder you will have to get some brake lines from the parts store. You want to make lines that screw into the master cylinder outlets and curve over and into the master cylinder reserviour as close to the output holes at the bottom as possible. This bleeds the master cylinder on its own without having to move fluid anywhere else. Once you have this setup just fill with fluid and pump the pedal until no air bubbles come out of the inlet holes in the bottom of the reserviour. This fills the master cylinder with fluid and gets all the air out. Which makes moving fluid past the master cylinder easier as none will move until you get some fluid into the master cylinder which is very difficult to do any other way.