T6.1 Brake Bleeding Problem

[DXX]

i had the van in getting the calipers painted. i don’t know what they’ve done but they can’t get pressure into the system, pedal keeps dropping to the floor

Then whoever did the work has a problem to fix.
Hopefully they didn’t use any aggressive chemicals that could have degraded the caliper piston seals.

 

[paxter]

yeah i thought so, they’ve had the van 8 days now. i’m hoping we have progress today

 

[paxter]

still no progress, apparently even vw master technicians are bamboozled with this one. i just want my feckin van back and working.

 

[DXX]

still no progress, apparently even vw master technicians are bamboozled with this one. i just want my feckin van back and working.

Assuming the fluid is at the correct level, isn’t leaking externally and air has been bled out.
A quick check would be to plug the discharge ports on the master cylinder and check if pressure can be raised.
If no pressure can be raised on the master cylinder then the master cylinder piston is either passing fluid internally or the master cylinder is leaking fluid in to the servo.

If during the caliper painting process air was allowed into the ABS unit the whole system needs to be flushed and bled.

I’m wondering if a pressure bleeding tool has been operated at too high pressure and has damaged the master cylinder seals????

 

[paxter]

master cyclinder does seem the obvious choice, I'm getting exasperated at this stage, just want my van back on the road!

 

[DXX]

master cyclinder does seem the obvious choice, I'm getting exasperated at this stage, just want my van back on the road!

It’s very easy to test, no need to guess. No idea which garage you are using but I don’t recommend using them again.