brake bleeding problems 300SDL

[jcciem]

I have applied pressure to the reservoir, and applied vacuum at the bleeder valve, separately and at the same time, no possible way can I get a drop of fluid to the front calipers. Rear bleed perfectly. All I did was change pads front and rear and now I have lost front braking and am unable to bleed the front system. Any ideas?




'86 300SDL 165,000
'87 560SEL 135,000

[Gilly]

I have occasionally seen a condition like this. it could just be that the holes in the calipers that the bleeder screws screw in to are plugged. Without any pressure applied, remove the bleeder screws completely and insert a small pick into the holes (anything of appropriate size and strength should work), then reinstall the bleeder screws and try again.

Gilly

ps also it could be the bleeder screws themselves are plugged. At the bottom of the bleeder screw (below the threads) you will see a hole drilled through which the fluid passes through when the screw is opened, are these cleared out?

[jcciem]

defective master cylinder, replaced the defective unit and all is fine!