Hi Guys
My brakes are locking up ( not releasing )
after a short time driving in lite traffic.

Last week I just made it home with the brake
locked up to the point the car barly moved
under power ( would not roll freely ).

Changed out the master cyc. but it's up
to the same thing today. It's a 65 Elco
with a 68 master cyc. and prop. valve that
has worked fine for a year or so.
any help would be great thanks bob

all wheels, one wheel, just fronts, just rears? Does relesing the line from the m/c make a difference? Does opening a bleed screw make a difference? More details please. Drum/drum, disc/drum or disc/disc?

Sorry about the little details, first all
four wheels lock up, the pedal becomes rock
hard. I've never tried to opening a line or
bleeder. and drum/drum. thanks again bob

try opening a bleeder first and see what happens. Then try opening one line of the M/C and see what happens. Another thing to check is when the wheels are locked up-unbolt the M/C from the booster and see if they free up, your booster could be hanging up and keeping the M/C pushrod depressed after you release the brakes.

Sounds like a master problem or at least a problem with pedal linkage. I would also check the power booster too.

Chris.

Drums on all four makes me think... you haven't changed brake shoes lately, and happened to turn them wrong (front shoe in the back)?

No Olle
brakes worked fine till last week. beleive
it be the power booster now, ordered a new
one. We'll see thanks bob

probably not enough head space between the M/C and the rod in the booster, there needs to be some space in there, I don't know the spec, maybe 1/16th of an inch, I know it isn't much.