brake gurus! chime in

[james05gt]

I was working on a 2003 Mustang v6 today, customer complains of a brake pulsation and grinding noise from the front brakes. So I checked it out and found an inop L/F caliper and the pads are metal to metal.
So I replaced both front calipers(new hardware), pads, rotors, brake lines, and did a fluid flush. L/F is still locking up bad when you put pressure on the brake pedal. I opened the bleeder and fluid flows nicely, closed the bleeder and pushed the caliper and it moves back and forth. It's not the slide pins because there brand new and I greased them with hi-temp brake grease.
So I traced the L/F brake line and it goes to the ABS unit, I'm thinking something is not releasing the brake pressure on that caliper, I am not positive if its inside the ABS unit or the master cylinder is faulty.
Its a dual brake system split front and rear with the front wheel brakes on one circuit and the rear wheel brakes on the other circuit. Also this is the second Mustang we had with the same issue, the last one was a 2001 I think which we ended up sending to a Ford dealership but that one had a hydro-boost instead of a power brake booster. Any insights?

 

[gil_t2]

Does that model have a combination block were it splits off to the R & L front brakes with a switch? If so I have seen the pin that contacts the switch stick and lockup the front brake calipers.

 

[james05gt]

It has a brass control valve mounted on the driver side frame with 4 lines attached to it. If that valve is faulty, that would explain why its not releasing the brake pressure on the fronts but only one side is locking up. I would have to mess with that valve tomorrow and see how it goes.