Join Date: Jan 2011
Location: Clarksville, Tn.
Re: clutch bleeding trouble!
Honestly, here is how I bench bleed... But first let me explain why you have to BENCH bleed and cannot bleed on most cars.
You have to bench bleed because the master cylinder when mounted to the booster, on most vehicles is not level, so the air bubbles get stuck at the end of the master cylinder (the highest point) and never come out.
On a pickup truck I usually drop the tailgate, and use the inner lip where the tailgate meets truck bedside, and vicegrip or c-clamp to that, very tightly at the mounting bracket part of the M/C. Usually that will get you level enough, check with a level though. You new master cylinder should have came with a kit with two short clear plastic hoses and two little plastic connectors that screw into where the lines go and a nipple for the hoses to connect onto. Go ahead and assemble all of that. Now, with a paperclip, or some way to get these hoses to route directly into the brake fluid resevoir 1/4 in. from the bottom, go ahead and do that. Fill master cylinder up 1/4 in from the top. Do not install the lid. With a big phillips screwdriver or maybe a really long t-handle extension or whatever you are comfortable using, push the piston slowly back and forth on the master cylinder watching the air bubbles come from the lines into the resevoir. When you withdraw back, make sure you give it enough time not to suck air bubbles back out of the fluid, or you will be working against yourself. Keep doing this (approx. 3-10 minutes) until you see no more air passing through the lines and the piston moves solidly through the whole stroke. Take the lines out of the resevoir, cap the resevoir, carefully and immediately install the M/C to the booster and remove plastic lines/fittings and reinstall brake lines and bleed starting from the farthest wheel from the M/C to the closest in that order. If equipped with ABS, you may have to bleed the unit.. Thats a whole 'nuther writeup.
Now you can bleed your slave cylinder, but like bert said, make sure that fluid stays mid level or higher, you cannot check it enough. You can save yourself some time if you open the slave cylinder bleed valve while bench bleeding the M/C. When you reinstall the M/C, let it sit for 15 minutes to run some fluid down to the slave and to your wheel cylinders/calipers, and this will partially gravity bleed your system. But you dont necessarily have to do that. Just make sure all valves are closed when pumping the brakes.
2001 Ford Expedition Eddie Bauer 4x4 (mine)
2003 Ford Focus SE (the wifey)