At the same time, I managed to free off the last of three bolts holding the hydraulic unit together. The front section has seals visible, one to seal the two parts together and one just inside the gold coloured tube. The booster has two o-rings. There is a bolt on each half of the unit. Perhaps someone knows if removing these allows access to the internals somehow. Both of these on the refurbished one have been removed, cleaned and plated. The master solenoid on the front looks to be held in with a clip so may also be removable.
What are you getting done by the guys in Edinburgh? Also any reason you are using them instead of the Portuguese company you used for the other unit?
I was looking to see if any of the 3 hydraulic pump motors from the 3 faulty ABS units lying about could be refurbished as the shaft's don't spin by hand or with power. From the picture above, I can see why one didn't work. Probably the first thing I would ask now from a seller.
A few updates with help from other owners of these ABS units. A Corrado G60 owner in Czechoslovakia had a bad leak from his pressure reducing valve so I sent one that I thought was good. It allowed fluid to pass through without being on the car. Using the two, he managed to get one opened to reveal his seals were the issue whereas mine was seized with corrosion. After reassembling his one, it was tested with compressed air and at 4 bar, nothing passed through so it looks like the unit is rated to 8.5 bar before pressure passes to the rear wheels. This presumably prevents the rear wheels coming on at the same time as the fronts hence it is sometimes referred to as a delay valve. He wedged a screw into the centre bore before attaching a slide hammer and managed to get it open. I'm not sure if a small screw went into the small centre bore or a large threaded bolt was used as in the 3rd picture but it came out quite easily. The solenoids can be tested individually. Pin 7 is common and pins 1-6 are connected 1 to each coil, so 12v across 7 and any other will test a coil. Listen for a snappy click. Finally, the ABS pump motors seem to be the main issue I have come across with them seizing due to corrosion inside. As this model of ABS was used on different cars around the same time there may be alternatives to check. The ones from a Jaguar XJS and Renault 21 both have ATE p/n 10.0511-9023.1 stamped on the casing and the connector looks the same. The ones used on the Ford Granada, Sierra and Scorpio all have have ATE p/n 10.0511-9032.1 stamped on the casing. In some cases, the wiring connector is different but they all look to still have the standard blue and brown cable so swapping over the VW one with a soldering iron should be no problem. Perhaps another to consider is the later Ford ABS pump which has ATE motor p/n 10.0447-0773.3 Looks similar apart from the connectors and the brown and blue wire do not connect to the rear of the housing. Perhaps with a bit of work you never know.
I took one of the ATE accumulators to the local Pirtek dealer in Edinburgh, https://www.pirtek.co.uk/service-centres/edinburgh/ , where one of their technicians Greg looked into replacements. He found a supplier who can supply one to the exact specs, 210 bar, 0.25L, M14 thread with a 4-5 week wait for delivery priced around £110 before delivery and VAT added. I've ordered one to try on my ABS as it can take up to 30 secs to prime when left standing for long periods and it's hard to tell if the pump motor is having to recharge it once it gets below 140bar while driving.
I managed to get hold of an ABS pump motor from a Range Rover P38 as it looked very similar to the one on the VW's. Wabco 4430010090 It is the same length and circumference and looks to have the same shaft that engages with the pump housing. It also has the same two wire connection on the motor. Missing is the welded on bracket that has a rubber bush, instead it has a bracket to hold the electrical connector. The main difference however is the alloy collar pressed on to the end. The VW accepts two bolts whereas this has three. Also the alloy collar is a different design. The thinking behind getting one was to see if the collar could be separated and swapped over to the one on the VW pump motor. As the pictures show, the collar is held in place at two points. Driving these back outwards allows the two pieces to come apart.
