Would the Abs light come on if there was air in it & it needed bleeding out? Have changed EVERYTHING brakewise, from discs to Master Cylinder but brakes are still rubbish after bleeding them a dozen times & driving - carefully - a few hundred miles, so am wondering if there is air trapped in the ABS pump. But shouldn't the ABS light come on if this is the case?
Brakes & Vag-com
- Thread starter tattybits
- Start date
I don't believe the ABS system will know there is air in the system.
I don't know what car you have, but some SEAT's also run the clutch off the brake fluid.
I don't know what car you have, but some SEAT's also run the clutch off the brake fluid.
Thanks Slimy. Lights are all working fine so am in a bit of a quandary - just assumed that if there was anything wrong with the ABS the light would come on !!! I have an old 2001 Seat Leon 1.8 T S [ before Cupra ] & it goes like a rocket so I need good brakes !! But haven't thought to bleed the clutch, which shares the same fluid . Will give that a try as soon as weather allows.
bleeding the clutch will make no difference to te brakes, the abs light serves as a warning for electrically picked up faults not mechanical ones.
Thanks MJ. Was wondering about that, but logically I thought that the ABS light would be unable to differentiate between air / fluid in the pump, so I was thinking that it wouldn't come on. However, Have been to dealership - quoted £79 for Diagnostic then, in addition, a charge for any other work !!! This seems a bit steep, so shopped around. VW dealer quoted £69 for Diagnostic, £60 for bleed including ABS pump, though wouldn't charge me that much if Diagnostic didn't take long. They also suggested it might be a problem with the Servo, but have checked all the hoses & they are OK, so am a bit stuck now - could be ABS or Servo, both expensive jobs. But nowhere will do a bleed without doing a Diagnostic first, which seems a bit of a rip-off when I know everything else has been replaced & is brand spanking new. A previous garage which changed the Master Cylinder for me put the car on the Brake machine to test it & said that it was fine, despite the brakes feeling soft.
Do they mean a VAGCOM check? Perhaps you could put a call out in the VAGCOM section to at least get that bit done? Although I doubt a dealer would take that as evidence and would still want to run their own diagnostic.
Personally, I would get it scanned for beer money, then take it to a local garage to be bled. Then if that doesn't clear it, you can start looking at the bigger bucks to fix it.
MJ, are you sure bleeding the clutch wouldn't affect the brakes? I'm sure there's been posts on here that suggest that because they share fluid, they could also share air bubbles? I agree about the ABS light though, the absence of a light suggests the electrical system is ok.
Personally, I would get it scanned for beer money, then take it to a local garage to be bled. Then if that doesn't clear it, you can start looking at the bigger bucks to fix it.
MJ, are you sure bleeding the clutch wouldn't affect the brakes? I'm sure there's been posts on here that suggest that because they share fluid, they could also share air bubbles? I agree about the ABS light though, the absence of a light suggests the electrical system is ok.
Have taken it to 3 different garges to be bled & all say car is OK, but they are unable to bleed ABS pump because they don't have the software to open the valves, so I'm pretty syuffed on that one !! Makes sense what you say about the Clutch bleed, though Dealership says that it wouldn't affect braking system ? ONLY things that haven't been checked are the ABS pump for air [ apparently it is possible that there is air in it as I had the Master Cylinder changed} & the Servo - but I am told that the brakes would be rock hard & not functioning if it was the Servo.. So I'm left with the air in the ABS pump!! Will let you know what happens when I get it checked in Dealership. I hear that EuroPerformance in Pontyclun are very good & cheaper than dealership so will give them a ring too.
What car is this on.
When I changed over my ABS unit - it was full of air, the ABS light didn't come on after I reset it.
I just bled the brakes the normal way. - im pretty sure if you have air in there it wont trigger the light.
Where are you from?
If a local member would scan it, it will give you the exact reason as to why the ABS light is on in the first place.
When I changed over my ABS unit - it was full of air, the ABS light didn't come on after I reset it.
I just bled the brakes the normal way. - im pretty sure if you have air in there it wont trigger the light.
Where are you from?
If a local member would scan it, it will give you the exact reason as to why the ABS light is on in the first place.
ABS light isn't on , it's behaving quite normally, which makes me think there's air in the pump. I'm from Bridgend in South Wales, & not many have Vag-com round here. After spending so much on the brakes I was expecting them to be spot on - new discs, pads, calipers, braided hoses, Master Cylinder, bleeding umpteen times - but brakes still soft.!! Can only think there's air in ABS pump
No, calipers OK. Bit of a mystery, so looks as though I'll have to bite the bullet & pay Dealership . URGHHHHHHHH!!!!!!!!!!!!!!!!!!!!!!
Shouldnt make a difference as the clutch system is fed from a different part of the resovoire on the master cylinder above the brake ducts so any air from the clutch slave or master cylinder will not be fed directly into the brake system
Yes thats right, just bleed the air using a pressure bleeder at 1bar of plressure - this is safe and will no leave air into the abs pump.
You can purge the abs pump using diag gear but if its been bled corrctly it will make no difference.
the abs pump is open constantly it opens further to reduce pressure to each brake, if you search how they work you'll see it uses small pistons which draw the pressure away in order to prevent wheel lock.
If there was air in the abs pump then it would flow out when the brakes are bled.
If there was air in the abs pump then it would flow out when the brakes are bled.
what car is it? if you have rear drums then try adjusting the handbrake or check that all the calipers/cylinders are all working correctly.
It's a 2001 Leon TS 20V 1.8, model before Cupra replaced it. Are you saying that bleeding the ABS pump won't make any difference ??? Everybody has told me that I have to use Vag-com to open the valves on the ABS pump so that brakes can be bled properly, and thus allowing any air out of ABS pump. I have discs on the rear, and the handbrake is really good at the moment. Calipers seem to be working OK - they are new too. Getting fed up with the car now though it drives well.
You CAN use vcds to purge the abs pump BUT if the brakes have been bled correctly then there should be no air in there in the first place.
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