ABS warning light, ABS pump internal wiring

[StormyTommy 0]

Finally got around to working on ABS problem.

 

Prodedure I followed to take out VR6 ABS pump/valve assembly. RHS/LHS is looking from front:

 

Do brake pressure removal routine;

Ignition off, pump brake pedal 20+ times - Safety warning - very high pressure in system.

 

Remove earth lead to battery.

 

To make space for getting to pump move the coolent expansion tank:

Unclip coolent level connector.

Remove trim at RHS of tank - it levers off, to expose 2 nuts! :norty:

Remove 2 * 10mm nuts - 10Nm (7 ft Ib).

Tank can now be moved as required (with 2 * hoses still connected) to get access to pump.

 

Unclip connector to large resistor on front of pump.

Unclip the plastic bracket that holds connector to body of pump.

Unclip cable restrainer from steel bracket on RHS of pump.

Unclip the spring bracket that holds resistor onto pump body and remove resistor and plastic bracket.

 

Unclip connector from front of ABS pump (valve block data cable)

Unclip connector from RHS of ABS pump (pump power feed cable)

 

Pump is held in place at 3 points by rubber bushings that bolt onto brackets, there are 3 hex metal pins on the unit that slide into the rubber bushings.

2 * 13mm nuts on LHS and 1 on RHS, I had to put pliers on one of the bushing/mount to stop it turning while undoing the nut.

Remove 2 nuts on LHS and remove the heat shield. I redid the 2 nuts to secure unit while removing pipes.

Loosen the nut on the RHS, the unit can lift off the bracket on this side.

 

Remove as much fluid as possible from resevour - I used squeezy bottle with length of plastic pipe to 'suction' it out.

Can't get all of it because of filter inside bottle.

Had considered it draining down from one of the bleed nipples, but decided to try and leave as much fluid in as possible to reduce air in system.

 

*** After this next point you will have air in system and be into bleeding the brakes, also note the safety message at start re pressure in system!

 

Undo 2 * pipes into LHS, these pull out (thanks to KipVR for tip), but were very hard to remove on mine.

I used a large screwdriver to lever the edge of the plastic fitting while pulling hard.

Need a container and plenty of rags to catch brake fluid that will drain out.

 

Undo 6 brake lines at front of unit, 5 * 11mm & 1 * 13mm.

 

Unit lifts UP off bracket on RHS and slides to right out of bushings on LHS.

 

That's ABS pump/valve assembly, part number : '1H2 614 217 A' removed.

Replacement is reversal of the above; fill with dot 4 brake fluid and do brake bleed procedure.

I had to bleed the brakes twice as pedal was very spongy after first attempt (drove it on a quiet road at night and worked the brakes hard, also activated the ABS), also did the 2 bleed nipples on ABS unit and the 1 on Master cylinder, note this is a different size than the 11mm ones elsewhere, I think it was 6 or 7 mm.

 

The above looks a bit complicated now I've written it down but most steps were easy with two exceptions:

getting the 2 pipes out of the LHS of pump and bleeding the brakes afterwards.

The 2 pipes took a lot of force to shift as mine had never been removed, however, they do go back in a lot easier as the plastic piece is v shaped.

Bleeding brakes when you've let air in is often a problem according to lots of forum postings and mine was the same,

was going to take it to dealer but they were ok after 2nd attempt.

[MikeVR6 0]

Nice writeup! :salute:

 

2 ECU's and 3 ABS pumps later. I completely removed the ABS system from my car so it would pass MOT. :(

[vw domo 0]

have the same problem after bleeding the system and fitting a new sensor, thought it was the sensor at first but the warning light used to turn off when hot so i gathered it was something in the engine bay. wont turn off at all now.

 

do you have a guide to checking resistances? not really sure where to start if it doesn't come up as a sensor fault on the VAG/COM.

[StormyTommy 0]

Nice writeup! :salute:

 

2 ECU's and 3 ABS pumps later. I completely removed the ABS system from my car so it would pass MOT. :(

 

Thanks, thought I should put something back into the forum as I wouldn't still have the car without the tips I've picked up here. :clap:

 

Good solution, ABS? What ABS?

[StormyTommy 0]

have the same problem after bleeding the system and fitting a new sensor, thought it was the sensor at first but the warning light used to turn off when hot so i gathered it was something in the engine bay. wont turn off at all now.

 

do you have a guide to checking resistances? not really sure where to start if it doesn't come up as a sensor fault on the VAG/COM.

 

Are you getting any ABS fail codes in Vagcom? Which sensor did you change?

Does the light flicker when ignition is turned on - this is a sign the ECU is doing its tests.

 

There is a guide at the start of this post on how to check the resistance of the solinoids in the ABS pump unit, however, the ECU checks the resistances and should latch a fault code if any are out of spec.

[vw domo 0]

Are you getting any ABS fail codes in Vagcom? Which sensor did you change?

Does the light flicker when ignition is turned on - this is a sign the ECU is doing its tests.

 

There is a guide at the start of this post on how to check the resistance of the solinoids in the ABS pump unit, however, the ECU checks the resistances and should latch a fault code if any are out of spec.

 

Ah, i see the guide now, thanks.

Yea i get the flicker when the ECU tests so im hoping that it comes up on the VAG/COM, it was a rear offside sensor iv changed but i had no problems when i changed the neerside rear not long ago. Had a replacement pump put on at the same time as the old one ceased.