Hey all, upon pulling out rear brake pads, found there is pressure in the system enough to push the piston onto.the disc, this would explain why my pads wore out after 2000ks???
On the other side I can lever the pads off the disc but they push back onto it straight away. What's going on? Is this an issue with the master cylinder?

1990 + ABS

 

As a first step, try loosening one of the bleed nipples and let out the pressure. The push the pistons back and tighten the bleed nipple and see if the pistons still tend to expand out. The flexible brake line that goes to the rear cage can fall to bits inside and block the line from allowing the fluid to fully return. If this seems to do it, replace the flexible. If not, then you have an ABS pressure leak somewhere which is always allowing the rears to be slightly applied.
Greg

 

Thanks Greg, I did buy a new hose, i'll try this when I get home and report back. hope it 's that simple.

 

There is also a pressure reducing valve in the line to the rear brakes on ABS equipped cars, this may be malfunctioning. I would check this next.

 

Thanks, released the bleed nipple and bled off enough fluid to release the pads, looks like that piston that popped out is now jammed. Will have to get the disc off. If I run out of ABS pressure then it won't reoccur until I start her up to rebuild pressure, will it. Getting smashed at work ATM hopefully I'll get back to it soon.

 

Got all the bits off, not looking forward to reassembly, what a pain! I need you guys to talk me out of pulling the entire rear suspension unit out! Can anyone advise on disc machining- whether to or not? What's the minimum thickness on the rears?

 

Most believe that dropping the IRS is the easiest way, overall. And if you are replacing the discs there's really no other way unless you have a hoist.

To remove the discs the lower control arms must be allowed to swing wayyyy down.....which means raising the car very high on jackstands. Higher than most people would be comfortable with.



New thickness is .500"; minimum is .450"

Just buy new ones. They're not expensive.

Cheers
DD