Brake problem

Several things could cause this. Old fluid with high moisture content can cause brakes to drag. Brakes dragging due to sticking hardware will cause excess heat which will boil the fluid and apply brakes. A bad master cylinder can stick and cause brakes to drag. A bad hose internally can cause brakes to drag. A bad vacumm booster can stick and cause brakes to drag. If you don't have the skills to check these items I recommend taking to shop of your choice. HTH, davidj92

Thank you David,it's driving me nuts.

The mechanic says he never heard of this happening before.

We disconnected the booster from the vacuum line and dove the car and it still does it.

Never had this happen but have heard of it happening to others: Replace the flexible lines to the wheels. Those flex lines can have a portion come loose internally that blocks the flow of hydraulic fluid, so after applying the brakes for a while they won't release because the pressure can't escape back through those lines. A good mechanic should be familiar with this phenomenon.

I'd go through the checklist davidj92 provided, starting with bleeding all 4 lines and continuing on to the next cheapest item on the list.

If your mechanic has never heard of dragging brakes and can't diagnose you need a new mechanic. If he's never heard of a vacuum booster causing a brake drag then he may not be so bad as a lot of mechanics haven't. As another poster suggested, start by bleeding your brakes. Bleed in the order RR, LR, RF and then LF. Bleed until fluid runs clear, monitoring fluid level in master cylinder to make sure you don't get air in lines. This is a good time to check slides or slide pins on calipers to see if they are dry. If so, this can cause drag, brake lube will solve this. When you test drive, if the brakes drag again, try pulling up on the brake pedal with your foot. If this releases the drag then you probably have a bad master cylinder or booster. More likely a master cylinder. Usually when the booster is bad you can hear a vacuum leak and if you disconnect the vacuum then the problem goes away. If not then when brakes start to drag, stop and crack each bleeder screw. If there is a lot of pressure and brake fluid sprays out under pressure then the flexible hose is bad internally causing pressure to hold. HTH, davidj92

David, when this happens the brake pedal has no travel-(after 10 or so minutes of driving)- I have normal pedal travel before driving. Are you talkng about the hoses on the wheels?

Thanks

Thanks Again David,I replaced the Master cylinder and it solved the problem,I did order the hoses and will install then as soon as I get them.

You gave me the confidence to proceed I am very grateful for all the advice.