Parking Brake Malfunction - Contact Workshop!

[snapdragon]

Thanks chaps. Maybe a wiring problem after all?
After testing in the house, I thought at least the motor and gearbox is OK.
Maybe the hall sensors are duff but cannot test.
I tested the two outer thicker cables resistance again, it was ~2OHM - I think I made a decimal place mistake last time when the multimeter was on the beep function.

I have cut the two damaged thick cables and resoldered them using my last bit of environmentally-unfriendly lead solder. Resealed the connector. for now but want to get one in stock and replace if it goes again.
I removed the big o-ring from the caliper and cleaned it all up and put silicone grease on. Blob of Tamiya grease in the torx-style caliper drive shaft. All seems ok now.

Screws to remove the motor were really stiff and I had to use the mole-grips on a T30 torx. I used blue loctite on refitting screws as it keeps moisture out and de-oxidises (reducing agent). I wouldn't fancy using the torx tool that comes in the car's tool kit! Once the motor is removed, you can wind the park brake caliper plunger back with a T40 torx, that turns VERY easily.

I looked at greasing the EPB gearbox but is is in the motor half that you can't get into so just used a little silicone spray in the exposed side to keep the moisture at bay - I also think grease may damage the nylon toothed belt that is in there.

https://www.youtube.com/watch?v=tAGR1bd_8KQ

https://www.youtube.com/watch?v=ThVKwHJWTLA

For future reference, the loom-side connector part number is 1J0919231
http://www.aliexpress.com/item/Allro...582661446.html

although on this one the outer wires on the EPB are more like 4mm thick so will try and find the right type and replace them.

[Architex_mA8tey]

I've bookmarked this rear epb on eBay if it's any use . . .
http://pages.ebay.com/link/?nav=item...obalID=EBAY-GB

[snapdragon]

Well, now I have another EPB problem on the same side.
Usual beeps, messages and icons, the brake was stuck on a bit.

Brake disk not reached.
Clamping force not achieved.

When the EPB is applied or de-engaged, it whirs for about 30 seconds as though a cog has stripped or a cogwheel clutch is slipping.

I removed the motor and operated the EPB and the motor and gear did turn
but noisily. I wound back the caliper with a T45 torx but when I refitted the motor it stuck it put the brake back on and left it there

I think I need to bite the bullet and get a new motor. They seem to start at about £220 which is almost the price of an exchange caliper. I'd rather just get the motor though to save opening the hydraulics and save the core charge while I return my old one and hope they deem it 'serviceable'.
I also notice that some exchange units don't have that thick foil/tin shield all over the plastic motor housing, what is that for? Interference? When you buy a new one from Audi, it comes flat and is self-adhesive you have to stick it on.

Has anyone seen them cheaper that £220?
Will try TPS on monday.

[Architex_mA8tey]

Originally Posted by snapdragon

I think I need to bite the bullet and get a new motor. They seem to start at about £220 which is almost the price of an exchange caliper.
Has anyone seen them cheaper that £220?
Will try TPS on monday.

That's about right but you're not allowing for the surcharge coming back off that - at ECP recently I paid £230 for one less a £60 surcharge by taking in my old unit when I bought the new one so only £170 paid

[snapdragon]

Thanks Architex, ECP seem to have doubled the price, maybe they are about to do a up to 50% off everything sale?
I managed to cut the lid off this thing and found it had cracked in what is the usual place. That may be the problem, it also had signs of rust and water ingress. I have washed the thing in brake cleaner and petrol until it ran clear. I can't see anything else wrong with it. there is no clutch. My current theory is that the swash plate assembly was able to pop past it's stops and the T45 spline drive was popping out of the brake caliper.
I can't see how the belt could slip or these cogs slip and the wobble-plate cogs/swash plate seem to tight and not damaged.

I intend on greasing it, fixing the plastic and maybe shimming or bushing out any slop and try again.

Looking on google, this is a common problem on VWs which is the same design but not an identical part and there are a few Passat threads about fixing them.

https://dl.dropboxusercontent.com/u/...5/IMG_3179.mp4

[Somerandomguy]

Cleaning it an glueing the motor back on will only work for a little while, the problem is that the motor mount corrodes which expands the mount and forces the cracks open again.

If you just replace the motor and not the caliper, there's a high likelihood that the new motor will crack again fairly soon because of the corrosion.

[snapdragon]

Today I refitted the part after, I plastic-welded and JB-welded with fibre-glass mat the casing and put everything back in greased with special silicone grease and resealed the lid on. Fired up and exactly the same.
The drive belt is rotating the big cog but when I apply resistance (to simulate brake applied) to the output drive the wobble-plate 50:1 reducer slips and makes the noise I was hearing. Everything was sound as a pound and smooth in the house so it must just be too much wear in everything, especially the offset shaft of the swashplate and it can't transfer the load anymore, thankfull ECP have put the price back down so ordered a new caliper Thanks guys.