Yeah, allot of those old Fords/Lincolns still have those phenolic brake caliper pistons in them. And in my opinion are trash. Replacing them with a good old tried & trued metal piston will be better in the long run.
Your problem may also be the brake booster staying on all the time. The problem could be a sticking relay or a bad pressure switch. To test if its a bad pressure switch, look over on the drivers side facing the last plug. You should see a 5 wire plug(if my memory serves me right). If the pressure switch is sticking in the on position, you should be able to disconnect that plug and the motor should stop. If it does finally stop, the pressure switch is bad and needs replacement. If it doens't make any difference, try the relay the same way. I believe the relay is on the firewall on the same side. From what I hear, Ford does not make these parts anymore, so you may have to call around for an aftermarket replacement.
Monday, August 23rd, 2010 AT 4:43 PM