I decided it was probally time for a brake change on my 240d considering the previse owner had most likely never done it. This should only take about thirty minutes but i encoutered some problems. When i pulled the first pads out on the right front one of them was down to the bare metal. Absolutely no material what-so-ever. The left side was not as bad. But When i went to put the new pads in for both sides the pistons would not retract into their bores and over a course of about 10 hours i was able to get them back in, replace both front brakes, and bleed them. I assume they had alot of crap in them but they eventually went back in. The back ones check out ok but when i went to bleed the right back one no fluid would come out so im assuming i have no braking power on that caliper. Any suggestions on how to free up the line?

It sounds to me like you need to rebuild your calipers in the front. Alternatively, you can replace them. Don't use them for long after they were stuck, The pistons and seal must be damaged for them to take a long time to retract.
For the back, remove the inflow line to the caliper which is rubber. You will need a flare nut wrench for this but a good open end wrench may do it. Then pump the pedal once or twice with the hose in a coke bottle and see if you have any flow. If there's flow, you need a back caliper. If not, you will need to trace the brake line back under the car to the master cylinder to see if it has been bent when the car was lifted before. The metal line is replacable if bent. If the caliper is bad, get a new one.
The calipers go bad like that when they are fully extended for a long period of time when the pads are worn out. Also, replace the front discs if you haven't done so. I wouldn't drive it personally till all of this has been done.
Steve

the previous post is not really wrong. but perhaps a little too aggressive.

it is true that the fronts might stick again or even leak but i would not expect a catastrophic failure just a gradual leak if it occurs at all. on the rear, it is not necessarily true that the caliper is not working. if it is not you will feel a pull when you brake. not being able to bleed it is a bad thing though and you should definately get it working or replace that caliper. you might be able to remove the bleeder and use a piece of wire to break the blockage. then if you haven't already you should at minimum purge the system and put in all new brake fluid. as for the discs if they meet thickness specs and arent vibrating your pedal when you put on the brakes i wouldn't change them.

it is never a bad thing to put on new parts but just cause they are old doesnt mean they are bad.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Yeah there is no vibration in the petal when i brake and i do have preety good braking power. The system is compleetly bleed with all new brake fluid but like you said that back right might have gotten cloged up with somthing.

As for front discs they do not leek at all but i noticed there is alittle pull to the right so that means i was unable to get it fully back into its bore. Slight rub.
There seems to be some metal ring that fits around the top of the piston and i notice that on both sides they were bent and patially coming off. Not really sure what this means. All the brake lines are fully intacked with no kinks and the right back is the only one that doesnt want to bleed. Hopefully its just clogged ill check today.

As for front discs they do not leek at all but i noticed there is alittle pull to the right so that means i was unable to get it fully back into its bore. Slight rub.
There seems to be some metal ring that fits around the top of the piston and i notice that on both sides they were bent and patially coming off. Not really sure what this means. All the brake lines are fully intacked with no kinks and the right back is the only one that doesnt want to bleed. Hopefully its just clogged ill check today.[/QUOTE]
You need to rebuild the sticking caliper. Make sure there's fluid in the rear caliper.
Steve

if pulling to the right it will be one of the calipers on the left that is stuck and not working.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

It would be the opposite

When you pushed the caliper pistons back in, did you open the bleeder valves first? If you don't, contaminated brake from the caliper is forced back upstream to the master cylinder. That could be the reason for your dry caliper. Also, the rubber brake hoses sometimes swell from the inside, restricting flow and sometimes causing calipers to stick.

Depends on whether the pulling occurs when the brakes are applied or when they are not applied. If the left brake is stuck "on," the car is not going to pull to the right.

At first we tried pushing them back in and they would not budge but i think we got some movement so yes some of the crap could have moved back up into the system but they were bleed later with 2 fresh cans of brake fluid so i doubt there was anything in there. Finally i disconected the brake lines and bleed valves and completly took the calipers off and drained them both. Both eventually went back in and were reinstalled and the lines were bleed. The right back one would not bleed and the brakes checked out ok so we did not push it back into its bore however there was no rubbing on any of the back ones. Im not sure if it is the line iteself that is clogged or the caliper i will have to check.

Let assume your aligment is perfect and you let go of the steering wheel and the car pulls to the right besides the fact that the beerings could be shot on that side most likely if your in my situation the right brakes are rubbing. It is not the left ones. Luckily for me it barly pulls so.