Bleeding Brakes :) - engine running or VAGCOM

[Expresso]

Hi there everyone,

I've recently bought myself a mk1 seat leon cupra (AUQ engine code from 2000), and I have a small question that I can't seem to find a specific answer to using the search functions (and google!):

When the brakes are worked on they obviously need bleeding to remove air bubbles. I have read that to do this properly the abs pump needs to be operated using "VAGCOM" or something... My car is at the garage right now having just had the brake servo and master cylinder replaced and the mechanic says that I now also need the abs pump replacing as the brakes still do not work correctly. He says that he is running the engine when he bleeds the brakes and that this is good enough to do the job properly - is he right? I'd like to know just in case I don't actually have to fork out for a new abs pump!

In short - is running the engine whilst bleeding the brakes sufficient, or is VAGCOM needed?

Thanks in advance for your help and also for your time in reading this!

Dave

 

[Allan_84]

when i bleed brakes at work i have the brake fluid under pressure (1bar), so if i open one bleed screw at the caliber, the fluid flows through.
and the pressure is from a machine thats pumps brakes fluid, so it will not run empty, if you know what i mean.

normal you start with the bleedscrew at the brake that is most away from the master cylinder if you take one at the time: rear passenger side --> rear driver side --> front passenger side --> front driver side.
when that is done you pump the brakepedal hard (engine off and no vacum), and check if there is enough fluid, then you check if the brake debal is hard (engine off and no vacum) maybe you do a short drive to check if the pedal feels right, firm when on the brake and not spongy, if you feel its spongy when driving, turn engine of and use all the vacum and then feel if the brakepedal is firm/hard when you push it, if not, you can try to do some brakes from 30-35mph with ABS in funktion 2-3 times (you can do it with higher MPH if you feel you can control it, but it is not needed) and then back and bleed the brakes again and repeat, the last step when you use the ABS is to try to get the air out of the ABS block if there is any.

im not sure the is any help in vagcom / VAS-tester for this car, if it was a 1P/5P (new leon/altea) there is a program for bleeding the brakes.

....My car is at the garage right now having just had the brake servo and master cylinder replaced and the mechanic says that I now also need the abs pump replacing as the brakes still do not work correctly......

dos he say why? any error codes? or cant he bleed it? maybe the reason has nothing to do with the bleeding of the brakes?

 

[phatchoonz1]

Worth making sure he's bled the master cylinder directly aswell.
There are two bleed nipples situated on the master cylinder which will need bleeding aswell, especially if the cylinder is new or has had air in it. I had this problem myself where the brakes still felt spongey after numerous bleeds around all the callipers. One quick bleed on the master cylinder and the difference was unbelievable!
As for bleeding the ABS pump, you can activate it manually through vagcom, so as you can bleed through the pump, keep plenty of fluid on hand if you do though! The pump really forces it through!