BRAKE PEDAL HAS ZERO PRESSURE MK7

[Bat135]

Ok. Yep. Just re read. Thanks for the advice. Will get one of those.

[dumper]

Possible the spring and valve arrangement between the two chambers of the master cylinder has collapsed and the cylinder is giving the same affect as a blown pipe / leak in one circuit

[T350camper]

I have experienced seals on a master cylinder being damaged (as mentioned before in this thread) by pressing the brake pedal to the floor during bleeding or by pushing the piston back in a caliper when changing pads and then disturbing something back up the line into the master cylinder. Granted, this was in the old days when the world was still black and white

Since then I always open the bleed nipple when I push caliper pistons back and capture the fluid via a bleed tube. When bleeding brakes I only ever press the pedal halfway down. Takes longer but never puts the master cylinder piston into a section of the cylinder it's never been before. Not had a problem in decades doing this.

[andz327]

Doesn't need to be forscan
Most diagnostic tools that has bidirectional functions will be able to bleed system

Sent from my SM-G990B using Tapatalk

[Bat135]

Thanks guys.

I bled it with a vacuum bleeder hand pump.

And finally got full working pressure. I did install the new master cylinder and bled the master cylinder when fitted instead of bench bleeding it. Then I used the vacuum pump bleeder on the callipers and all fine.

A lot of air in there. I advise from my experience not to use those one way valves…. The hand held pressure bleeding lump much better for one man operation. I replaced all bleed nipples to with new ones. I suspect the master cylinder was ok but replaced it anyway. Think it was just trapped air.

The billed nipples on the rear were so arkward to get to. Wuth ring or open ended spanner. Even with wheel off. Ridiculous that the hand brake cable is in the way. A real design flaw imo but must be a reason. Can’t see why they couldn’t make the nipples easier to access. Could hardly get a turn on it at all. A lot of swearing.

If somebody else is planning on bleeding thier brakes get a few spare nipples as those rear ones can easily round off.

Alls well tbat ends well.

I don’t know how my dad coped all them years being a mechanic. I wouldn’t wish it on anyone. Always something that goes wrong or a problem… stuck or rounded bolts. Stuff snapping. A real pain the proverbial. Even joust being a fitter is a head ache. I will stick to bring a gardener thank you very much.