ON the Mark 4 golf its behind and hidden by the air filter on the right side.
My ABS module was toast when i recently got the Golf. Intermittent signal faults from ABS, and other systems in car reporting communication faults with ABS. Permanent ABS light and flashing red light on dash.
I found this to be a very straightforward repair despite my initial uncertainty.
Purchases:
- Bought a working unit from a breaker on eBay off a skoda (same part number) for ÂŁ16 delivered.
- Bought a pressure bleed kit of amazon for about ÂŁ30 ( A Sealey unit with a big discount)
- Bought 5 litres of brake fluid DOT 4 for about ÂŁ16
Other tools / materials:
Jack
Axles stands
Paper towels
Flare nut spanner (I ended used an impact socket since my bleed nipples were pretty rusty). I thought it odd the 2 front bleed nipples are 10mm and the rears 11 mm.
Releasing fluid (I make up 50 / 50 acetone and ATF and apply it with a small dentistry irrigation syringe a few drops on each bleed nipple thread and leave for a few mins. I found this is the best releasing fluid by a long shot.
Method
Removed old ABS. ECU cable, 6 pipe and 3 bolts. I capped the pipes with the rubber bleed nipple caps to stop fluid loss / air ingress. Cable tied ECU cable out of the way with a plastic bag over it to stop dirt etc).
Fitted replacement ABS and ECU unit
Had a small delay here in as much as one of the solid brake pipes i bent slightly removing the old ABS pump and i had to carefully encourage the screw thread back in - thanks to my neighbour - needed the extra hands to avoid stripping the thread.
Pressure bleed system. You are supposed to get VCDS to cycle the ABS pump to bleed it. For some reason it would not on mine so old school - down a gravel track at about 30 and stamp on the pedal till stopped with ABS clattering away., Repeat a few times for good measure. pressure bled again (no bubbles this time so pressure bleeder had already done its stuff). In the end i put about 2.5 litres through the system to replace all the old fluid at the same time. The Sealey pressure bleeder makes it so easy to bleed the brakes, and pressure bleeding is the way VW recommend.
Interestingly Bently manual recommends bleeding the opposite way i was taught - starting closest in and working farther away was the method i followed per the manual.
Brakes are fine, ABS system now working fine.
I took my time. Had a delay with one of the unions on the ABS pump not lining up properly, and having to recreate a nut on the clutch bleed nipple because of rust - 10 mins with a fine file sorted that. Triple checked everything - it is after all the brakes. About 4 hours from start to clean tools and all put away.