02 ford expedition 4.6. Front rotors replaced, rear rotors turned within specs, all pads replaced, master cylinder replaced and all air bled out, no visible fluid leaks but pedal still bleeds down with light constant pressure
Country: United StatesMake: fordModel: expeditionYear: 2002Engine: 4.6
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Hello, I will try to help. Did you bench bleed the master by chance? Air in the master cylinder can be very difficult to get out if it's just bolted on the vehicle and then brakes are bled.
dont know how to bench bleed the master cylinder. please help
OK, the master cylinder box, should have came with a couple of adaptors and a hose kit, did it?
adaptors and hoses that kind of look like this? http://www.google.com/products/catalog?hl=en&q=master+cylinder+bleeder+kit&bav=o n.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1152&bih=725&um=1&ie=UTF-8&tbm=shop&cid=17639961940506054996&sa=X&ei=GUetT9-7EoiG8QSOt-WLDQ&ved=0CMMBEPMCMAA If it didn't come with those, It's really going to be easier if you can get someone in the truck now to help you bleed it.Eclayton441040.7160305903
Im sorry, the mechanic said he did bench bleed the master cylinder
OK, 1 of 3 things is happening if your pedal is fading down. Either, 1. the system has air in it, 2. the new master cylinder is internally leaking. (not likely) 3. Something is leaking brake fluid on the truck, like rear wheel cylinders or calipers. Tell him to check the rear wheel cylinders, (if it's rear drum brakes) or all the calipers for any leaks. What he needs to do, Is get someone in the truck, fill the master cylinder up completely, have the person in the truck pump the pedal 5 times, and then hold pressure to the brake pedal while the bleeder is loosened on the passenger rear bleeder screw. always work from the furthest point away from the master cylinder to the closest point, like passenger rear, drivers rear, passenger front and then drivers front. It's got air in it somewhere if it's not leaking and the new master cylinder isn't bad. I've gotten a few new parts that have been bad before. But it is very rare. If he is SURE all the air is out, I'd try another master cylinder. Wherever he got it from will likely warranty it.
I have the vehicle back only paying for parts and mechanic says he doesnt know what to do so am trying to repair myself.
OK, I understand. Here is what I would try, Get somebody in the vehicle, Remove the brake lines from the master cylinder. Get a pair of latex gloves, fill the master cylinder completely full, Put a towel under the cylinder to catch and brake fluid. (Paint and brake fluid don't mix well). Have the person SLOWLY push the pedal all the way to the floor. Let the fluid leak out. When the pedal hits the floor, tell them to HOLD the pedal on the floor, and you cover all master cylinder holes with your latex gloves, so when the pedal is released from the floor, it sucks fluid into the master cylinder ports, and not air back in the cylinder from where the brake lines are screwed in, (because you cover the brake line holes with your fingers. wear latex gloves when doing this). Repeat this until you see absolutely no air come out of the master cylinder when the pedal is pushed down. Then crack the bleeders one by one and let them gravity bleed for a few minutes. Keep an eye on the fluid when you do this. I believe that will fix your problem.
ASE certified. Auto Transmission rebuilder for Ford Motor Co. from 91 to 2000