[graemma1]

my car has been standing for 2 months and all was fine before i parked it up, took it out today and after 2 miles the brakes started smoking and bound on completley, i removed calliper and released nipple to force piston back, now when i pump the pedal there is nothing, the piston moves a tiny bit but not enough to close the gap between pads and disc and also the is no braking from the other 3 wheels. Any help would be appreciated.

 

[imkenny]

It sounds like there is air in the lines. Remove the brake fluid filler cap and loosen the nipple to see if they will drip bleed all the air out (dont let the resovoir run out of fluid)

 

[graemma1]

i believe it is the master cylinder, even you pump the peddle and open the bleed nipple nothing comes out, not air or fluid. there is no pressure, upon further inspection the fluid in the reservoir is green which leads me to believe this is mineral based and this could have damaged the seals in the mc and potentially all the callipers.

 

[captain_video]

VW's use DOT 4 brake fluid, not mineral oil. They use mineral oil for power steering fluid. I use Valvoline Synthetic DOT 4 brake fluid, which should be available at most auto parts stores. I got mine from Advanced Auto Parts.

 

[ylwagon]

i believe it is the master cylinder, even you pump the peddle and open the bleed nipple nothing comes out, not air or fluid. there is no pressure, upon further inspection the fluid in the reservoir is green which leads me to believe this is mineral based and this could have damaged the seals in the mc and potentially all the callipers.

This is going to be a lot of work, because the entire brake system will have to be flushed. Potentially the caliper piston seals will need to be replaced too. You might need a specialist on this one.

 

[JayTheSnork]

almost ALL brake fluid, over time, will turn greenish - chances are, this is the case, or you are looking at the power steering reservoir vice the master cylinder reservoir.

I find it hard to believe that your master cylinder died after sitting for two months. it sounds more like you have a stuck caliper, and then introduced air into the system when you cracked the bleeder valve (which you DID NOT need to do - loosening the cap on the emaster cylinder reservoir, then compressing the caliper would do the same thing).

 

[Electron Man]

I'm with Jay. If you were able to stop the car with the brake pedal (with a siezed rear caliper no less), your brake MC is likely OK.

If you don't have a pressure bleeder, you need to take the car to a shop or "pump-bleed" each caliper in this sequence (RR, LR, RF, LF) to get all the air out of the brake system.

Whomever helps you with the bleeding needs to be informed NOT to press the brake pedal down too far (2-3 inches max.) when pumping the new fluid through the system. If the pedal is pushed too close to the floor, the seals inside the MC will be destroyed...I've seen it many times.

 

[ylwagon]

Brake fluid has a unique smell, feel, and low flammability that you should be able to distinguish from mineral oil, which is slippery and burns smoky.

 

[sirwired]

Whatever you do, I'd just install a rebuilt caliper when it's time for that step. It's already seized; why mess with trying to fully evaluate and repair it? Rebuilt calipers aren't that much, and probably cheaper if you don't already own the tools needed to perform a proper rebuild.

And depending on the age of the car, you may want to go ahead and replace the brake lines while you are at it...