i have a 1200 wagon with disc brakes on the front, recently the more i used the brakes they would start to stay on to the point where the were completly locked on, i tried a new brake master which didnt solve the problem, i then tried changing the piston seals and the brake pads but still hav the problem, does anyone hav any idea wat the problem could be? its only happening on the front not the back

sounds like a piston is jamming in the caliper

does it pull to one side when you brake? or when you let the brakes off but it is still rubbing?

residual pressure valve inthe master cylinder...

Have you recently changed from drums up front?

all 1200wagons came with drums up front from factory. i put kb110 struts and brakes into my wagon without removing residual valve and had no problems what so ever so the whole time i was driving on them. nada, zip zero and they went well.

I'd look for a 120Y master cylinder, using a car's MS that had a disc/drum combination from the factory.

Does sound like a residual pressure valve issue, but it's also likely you have crap in the master cylinder.

If you could be bothered, Pull out the master cylinder and give it a cleanout. including clearing the air galleries from the MC bore to the brakeline fittings with a paperclip. put brake fluid on everything and reassemble.

I

Make sure you have some clearance between the brake pushrod and the master cylinder piston when the brakes are off. If not the compensating port could be blocked due to the piston not fully retracting and as the fluid heats up and expands, it locks the brakes on. I've had this happen before on a P.D inspection due to bad master cylinder to booster clearance and it resulted in very smoky brakes.

thanx for the feedback, tomorrow ill try adjusting the push rod clearance, if that dosnt work the try replacing the rubber hoses but im not sure if that is the problem coz its happening to both the front brakes at the same time, ive replaced the master cylinder with a new one so its not the residual pressure valve

one thing to try before u get too invovled with removing and testing other things, lubricate the brake pedal pivot point where the pin goes through. we recently had the exact same problem on our race car and we ended up replaceing the mastercylinder and rechecking the pushrod adjustment a few times and it all turned out to be a seazing pivot point.