finally came round to replacing discs and pads on the front of my 98 2l S40, the caliper would not go back and ended up with the piston popping out after that went back in with a bit of a struggle,
once other side was sorted and off jacks started engine but brake pedal went straight to floor nothing????? have bleed brakes tonight and still nothing can someone please help.

 

I am not sure how you got the piston to pop out unless you were pushing on the brake pedal while the caliper was off the vehicle. At any rate, the rubber 'boot' that seals the piston in the caliper may have ripped. If in fact you are not leaking fluid out of the caliper then I have a feeling that you have not bled the brakes correctly. You must have lost about 1/2 pint of fluid when the piston came out. How much did you add to the master cylinder? 1/2 pint at least? The first thing you want to do is open the bleed screw on the caliper that the piston came out of. When fluid begins to come out, cap it off and then start the correct bleed procedure by first bleeding the right rear cylinder.......then the left rear...........then the right front...........and lastly the left front. Your vehicle uses DOT 4 fluid..........not DOT 3!! You will need at least 1 liter of new fluid.

r.

 

Hi tozee, I think you can bring your car to an automotive shop so they can check what's really going on to your brakes. If you need replacement for your car's brake, you can visit car parts store online they have wide selection of car parts. Last weekend my uncle's friend bought a new Volvo 240 brake pads online.

 

I just had this same problem when I was doing the rear rotors and pads on my 02. I was impatient and I didnt think the piston was going in when i turned it so i tried the other direction. The piston popped out just like you describe. Eventually I got it back in there, but my pedal was mush when I was done. Ended up bleeding all 4 calipers, starting with the one that popped out. It took a long time to get all the air out of there, make sure to keep a close eye on your resivoir. And just keep going until you dont see/hear any more air come out.

 

There is one thing that most of you guys are forgetting to do, more rudimentary than bleeding them, when you have installed your new brakes, you have to pump the brakes back up once you replace them. It's really easy, start the car and pump the pedal until you feel that all the slack is taken out of the pedal.

 

It's possible that he my have lost so much fluid that air is now in the master cylinder. Sometimes you have to bleed the air at the master cylinder before you head off to each of the bleed screws at the wheels. I would first check to see if there is any damage at the piston that came out of the caliper. Then check to see if you ran all of the fluid out of the master cylinder. If for some reason the master is air bound you will have to bleed it by removing the lines at the master and replacing them with rubber ones that you can turn back into the reservoir (now pump the brakes with the help of an assistant). I can't imagine it got that bad but it is possible to lose a lot of fluid from one brake cylinder that went bad.