Bench Bleeding Master Cylinder

[02x72]

For the life of me I cant get this damn thing to bleed. Two from Napa, and one from Orileys and they are all doing the same thing. won't build up pressure on the bench, and when installed the pedal has no resistance. All of them were new, not rebuilt. I am replacing it because the old one is going out, but its still better than any of the new ones. Ive tried it with the plugs, and the line kit on them all, and have pushed each one in probably 200 times. What are the odds of getting 3 bad MC's in a row? Im following the procedure to a tee.

 

[franklin2]

If you use the plugs, you have to take a wrench and tighten them as much as you dare without stripping the threads. If they suck a little bit of air when you retract the plunger, it will not bleed out. You should be seeing little bubbles coming out of the reservoir each time you push on the plunger while using the plug method. If you just keep seeing bubbles and the stroke does not get shorter, you are getting air in around the plugs.

If you use the line method, of course the lines need to be submerged or they will suck air each time you retract. The lines need to be tight on the fittings, or they will suck air also. Make sure you push slowly and go full stroke till it stops. I believe that is why bench bleeding is so important, to get the plunger to travel full stroke to get all the air out.

 

[02x72]

I thought the plastic plugs would be a problem as well, so I installed brass plugs nice and snug into the ports. After a few strokes the bubbles stop but it still wont build resistance. Each time the stroke gets a little shorter, then just stalls there

 

[franklin2]

Using the plug method, I have had some get where the stroke gets shorter and shorter till it will not budge any at all, and I feel satisfied that ALL the air is out. But others I have done the stroke gets shorter and shorter till it will not get any better, and I still have about 1/4 inch travel before it stops. But when it stops, it stops solid and doesn't seem spongy, so on those I call it good and I haven't had any problems with them.

 

[02x72]

I ended up getting it. The whole keep it level thing is a load of crap. Once I took it out of the vice and started pushing the MC in with it at all different angles it worked. Thanks for the help guys