Brakes!

[utahseries]

Ok, i've posted this on numerous forums now, but i'll need all the minds I can to think of it!! Two weeks ago, out of nowhere, the brakes practically locked up on the 1967 109.. There is no play in the in the pedal, it won't go to the floor at all.. I had to drive it into the parking lot in low range!! All four brake drums were unusually hot.. We replaced the flex lines, because they hadn't been done since we bought the car.. And we replaced the return springs.. It still acts like someone is putting all their weight on the brake pedal when we try and drive it? Could it be the master cylinder? I'm astonished that a system this simple is stumping me!!

[SafeAirOne]

Sometimes a tiny nugget of deteriorated rubber will get stuck on one side of an orifice in the system, allowing brake fluid to flow out TO the wheel cylinders, but block the fluid from returning to the master cylinder like a little check valve. Often it is only on one wheel, so is easy to track down. If this is your problem and it is happening on all 4 of your wheels, is is likely in a line or component common to all 4 wheels.

EDIT: You'll probably need to flush the system to purge the line(s) or item of this nugget in addition to replacing the item giving off rubber nuggets. Also, be sure to use LMA brake fluid.

[junkyddog11]

I'd say that the master cylinder is locked up, like enough pressure in them to actuate the brakes. Have you used some sort of wrong fluid? Seen this issue in the shop several times lately, swelled everything up enough to lock the brakes. If you back of on the pedal to master cylinder adjustment you may get the brakes to come off.