helping my buddy bleed thebrakes on his 300... changed the master cyl.... bleed the master alone first.. then bled at all three wheels still weak brakes although no air coming from bleeders... any thoughts?

 

try doing it like you do a car. start from the farthest caliber from the master cylinder then work your way closest,ending with the master cylinder. may take a bit.

 

it has a small air bubble trapped somewhere

 

tough little sucker might try vaccume pump to try and draw it out

 

when i replaced the M/C on my 300 i had the same problem. this is what i did. get some clear plastic tubing that fits the bleeder screw tightly. get a clean coke bottle,put some clean brake fluid in it. put the open end of the tubing in the bottle open the bleeder screw and slowly but smoothly pump the brake lever untill you no longer see bubbles in the fluid that is in the bottle.do this at each caliper. as mentioned above start with the caliper farthest from the M/C. when finished, remove the M/C lid,crack open the line at the M/C and let it drip for a minute or so, keeping the reservoir full. any air left in the system will travel to the top.

 

sounds like its worth a try..... ill let you know

 

I had a similer problem with my dad's 400 on the rear master cylinder. I put a vac. pump on the bleeder and sucked all the air out. It worked great for me.

 

i got it..... vaccume pump.... done in 15 min...