Rear Brakes Locking Up When Hot

[SiR_RB]

Took my car for a drive today and after about 20 or so minutes I could feel the car didn't want to roll, afew minutes later it got even worse to the point where I had to go from 4th to 2nd just to keep it moving

I stopped and smoke was coming from back brakes and pedal was hard

I let it sit for about an hour to cool and drove it back home no problems until I was just in my street and it started again

I took the rear pads out and I couldn't put both pistons in at the same time, it was asif somfin was stopping the fluid from returning

I'm about to change the fluid tomorow, can I be this? Or could it be the master cylinder?

Car is r32 Gtr with 33 Gtr brembos all around with braided lines, was like that when I bought it and have never changed the fluid in my ownership (9 months)

Any help would be great !!

[89CAL]

Sounds more like your park brake shoes are rubbing and when they heat up they lock on

If your rear brakes are rubbing as suggested then you should see uneven wear on your pads

[SiR_RB]

Pretty sure it's not the handbrake shoes because the rear brake calipers and disc surface where the pad goes we're extremely hot, I can see afew heat blisters on the caliper due to the heat

I'm gonna change the master cylinder and brake fluid today nd see how it goes

[SiR_RB]

All fixed !

Ended up changing/flushing brake fluid with motul 5.1

New brake master cylinder

= win

[MrStabby]

Nice - I wouldn't have thought a master could fail that way. Its good to be educated.