Front Driver’s Side Brake Caliper Locking Up Randomly

[WestonE]

This could be simply pistons sticking in the caliper. I would be installing a fully re-furbished set of front calipers with clean lubricated slides. The forces in the braking system are far stronger in brake application than brake piston return. 

[George-S]

Hi all,

I’ve installed the reinforced rubber vacuum hose I mentioned earlier for the brake servo.

I also rearranged the brake lines on the master cylinder. Initially, I had both front driver's side lines connected to the same single outlet port. I’ve now staggered them—one to the front and one to the rear outlet of the master cylinder as shown in the Haynes manual.

I’ve driven the car three or four times since making the changes and pushed the brakes fairly hard. So far, I haven’t experienced any brake locking.

Hopefully stays that way...

Cheers George

[HFStuart]

I had both front driver's side lines connected to the same single outlet port.

99% that will have been the issue.

I haven't quite worked out how that would have meant the rest was plumbed in but it seems likeley that the rear compensator valve would have been in circuit with one of the large front caliper cyinders it wasnt supposed to be. Braking hard would make the rear lift, closing that valve causing pressure variations at the front. I'm surmising here but it sounds plausible.

I hope it's sorted as it sounded pretty dangerous.