Need To Bench Bleed Master Cylinder, Help!
 

okay so my master cylinder came with these tubes for bench bleed it, but my brother and i have replaced master cylinder before without dooing this, so we didnt *DOH*. i know, i know, im stupid and i suck. i no longer have the instructions for how to do this so if someone could explain it, and make my car run, i would appreciate it. I'm going to continue searching but if someone could just explain it real quick it would make things 437427 easier.

There should also be some screw in things that the hose attaches to. YOu put in the screw in things attach the hoses to it. Run the hoses around so they squirt the fluid back into the resevior. Fill the res. Take a screwdriver and plung away. You'll see the fluid racing around and around as you plunge. Simple

What I don't understand is, you have to take the screw in thingys off to put your brake lines on......so doesn't the air return to the areas you just bleed it out of??

Anyway. I know I botched my bench bleed process and I didn't like th fluid all over my bench so I just stuck my MC in and bleed the system the same way I had been doing for years.......worked fine.

You don't have to bench bleed, I've never had to before, I just bleed the part normally after installing it.

"pump" *release bleeder screw, watch fluid come out, retighten bleeders screw* "Release"

"pump" *release bleeder screw, watch fluid come out, retighten bleeders screw* "Release"

"pump" *release bleeder screw, watch fluid come out, retighten bleeders screw* "Release"

"pump" *release bleeder screw, Notices AIR BUBBLES coming out, retighten bleeder screw* "Release"

"pump" *release bleeder screw, watch fluid come out, retighten bleeders screw* "Release"

"pump" *release bleeder screw, watch fluid come out, retighten bleeders screw* "Release"

Is it possible to "bench bleed" a master cylinder on the car (using the brake pedal/pushrod to press it)? One master cylinder instruction manual I ran across said this was a bad idea, but I don't see why. I lack a vice to clamp the cylinder into, mostly.

-=Russ=-

:werd:

I don't consider it a bench bleed if you have to break lines to install it back in the car, because you've got to bleed it yet again on the long hydraulic runs now.

When I rebuild my clutch master and slave cylinders, I leave all the lines on, rebuild both, then bleed everything on my workbench. After that it goes right back in the car with no further bleeding necessary. THAT'S what I call a bench bleed...

If you're having trouble getting the MC to prime, totally remove the bleeder screw on a rear caliper so that you can get the fluid flowing. Keep your finger over the hole. Once you pump the brake the brake peddle 3 or 4 times like this, the MC should be primed. Put the bleeder screw back in and bleed normally after that...

okay, ive got my system all bled, or so i thought, but i sitll have no brakes. there was a random vacuum leak that was messing with my brake booster i think, and i put it back in and it helped. i bled the brakes with the ebrake on (which i think is a big no-no?) well now, the brakes feel good and stiff with the ebrake on. then, when i put the ebrake down, the pedal slowly sinks to the floor. is this just because i bled it with the e-brake on? im going to rebleed it tomorrow with the ebrake down and see if it helps but if anyone has any insight i appreciate it.

Don't know for sure, but it would probably be a good idea to keep that e-brake OFF for bleeding, to allow piston travel on the rear calipers...

Still, that shouldn't have caused your peddle to go to the floor after you bled 'em, unless you still have air in the back calipers caused by the void created by having the e-brake on.

Try it again tomorrow :)

You still have air in the system. I used three of those 12oz bottles when I did my brakes. The brown stuff just kept coming out and as long as the old was still coming out then I new the bubble was still behind it. Once you "SEE" the bubble come out you should also see the new fluid coming out as well. As long as it is brown you know its still the old stuff which you want out anyway.

get a small piece of hose that will fit over the bleeder screw and place the other end in a coke bottle. What this will do for you is you'll see the air bubbles in the fluid when they come out. Some try this trick in order to not have to close the bleeder screw when your not pumping, ala a one man show. But this NEVER works as the hose always seems to slip off or not fit tightly enough and allows air back in.

i have the hose setup going on, and have discovered a leak in the rear caliper. im going to gravity bleed it tonight and hopefully have a new caliper by tomorrow to redo everything, this is a painnnnn.... thanks for all the help so far guys, hopefully this caliper fixes it.