Abs pump bleeding

Nov 8, 2020
2
0
Hi, I know this subject has probably been put up loads but I just can't seem to find the answer I need,
I took my abs pump off to replace to find out that it's the wrong one so putting the old one back on for now but I can't get a decent brake pedal now. Using vcds to bleed the abs pump it states everywhere that you go into basic setting and there's an option for bleeding the abs but my version of vcds doesn't have this option but I can run the pump through output tests, my question is how long do I run the pump for and do I open the bleed nipples when I run the pump?
Thanks in advance
 

Rusty2k

Active Member
May 12, 2013
498
57
You shouldn't need to cycle the pump. The workshop manual procedure is to use a pressure bleeder and keep the pressure below 1 bar (approx. 14 PSI). Above this pressure a valve in the ABS unit closes and shuts off some fluid chambers which could leave air trapped.

The bleed order specified is

Rear right
Rear left
Front right
Front left
 
Nov 8, 2020
2
0
I've bleed the brakes 4 times so far, I've used the gunson pressure bleeder was more than 14psi though, I've gone it via the old school method with the pedal up down up down up down ahaha
And then with a vacuum bleeder and then I used the pressure bleeder and vacuum bleeder together which actually worked brilliantly, I've ran the abs pump output tests with vcds on the last attempt and did get some more air out of the front right brake line, but I still get a soft pedal the brakes do work but no where near how they used to and applying pressure to the pedal it slowly sinks, spoke to a friend and he reckons that when I run the abs pump I need to open the bleed nipple to let the abs pump flow fluid throw it and on vcds there is an option to run a bleeding routine which tells you to open the bleed nipple and then the pump runs and then pump the peddle and shut the bleed nipple but for some reason my vcds doesn't have this option,
So I need someone with more knowledge than me that knows how long I need to run the pump and when and how long to open the bleed nipple
 

Rusty2k

Active Member
May 12, 2013
498
57
Not all ABS units have the auto-bleed function. If the option is not there then the unit does not support it. I don't recall ever seeing this as an option when I've been looking at my ABS unit in VCDS.

But, as I said previously, running the pump is not needed. Just use a pressure bleeder kept under 14 PSI. If it works for Seat there's no reason why it shouldn't work for you.

edit to add: If it's a manual don't forget to bleed the clutch too, after the brakes.
 
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