Reply to "Brake pull. ."

Phil, this is common and is almost always caused by one or more stuck pistons in a caliper. Thats what gives you "differential pressure". The good news is, in nearly all cases, the fix involves lots of labor and no cash at all unless there a leak. I've described this operation in detail, with photos, in the POCA news several times. Remove the caliper mount bolts & coat-hanger the caliper so its not hanging by the hose. Put a drain pan under the area, remove the brake pads and have someone gently step on the brakes while you watch the pistons move. One won't. Block the three that do move and have your assistent really tromp on the pedal; it WILL move, eventually. As it blows out, you'll discover why the drain pan is there (watch your eyes)! The piston is stainless steel and built-up varnish can safely be scotch-brite-ed off with no damage. Wipe out any debris in the caliper body, too. Reinstall the piston and the rubber dust boot that also blew out, bleed that caliper of air and you're done.... for a while. The sensible thing would be to do all the pistons in both calipers, change the fluid and be done with it for another decade. The rears rarely give trouble except for sticking e-brake cables.