allroad V6 TDI slow build

[gldgti]

So we were going away for the weekend until the car wouldnt raise up. Limped home thinking it was either the compressor, a bag gone or both. Got home and checked all the bags and definitely no leaks. So, pulled the compressor again and started troubleshooting...
After a few tries experimenting beach testing, I realised the compressor would run bit not start when voltage was applied when it was stopped in a particular position. So, after adjusting the preload on the brushes, polishing the commutators and still no real improvement, I finally noticed that 2 wires going to the armature were cracked just near where they looped around the connection to 2 of the commutator bars. This meant that spots on the commutator were basically dead and hence the compressor would start sometimes but once it stopped in a dead spot that was it.
So, I soldered the windings back onto the commutator and boom, the damned thing runs like NEW.
Makes me wonder how many compressors get replaced for this relatively simple problem, not even hard to fix once you realise what it is!

[Ryeman]

So we were going away for the weekend until the car wouldnt raise up. Limped home thinking it was either the compressor, a bag gone or both. Got home and checked all the bags and definitely no leaks. So, pulled the compressor again and started troubleshooting...
After a few tries experimenting beach testing, I realised the compressor would run bit not start when voltage was applied when it was stopped in a particular position. So, after adjusting the preload on the brushes, polishing the commutators and still no real improvement, I finally noticed that 2 wires going to the armature were cracked just near where they looped around the connection to 2 of the commutator bars. This meant that spots on the commutator were basically dead and hence the compressor would start sometimes but once it stopped in a dead spot that was it.
So, I soldered the windings back onto the commutator and boom, the damned thing runs like NEW.
Makes me wonder how many compressors get replaced for this relatively simple problem, not even hard to fix once you realise what it is!

Cars with 'air' suspensions, as far as I'm concerned, are are ok if a business expense but from my budgetary position are a complete no-no/nightmare of added complexity and unreliability.
Is there a vehicle with such that has a good reputation?
It'd be nice to think that you've found the weak link and will never fail again.
If there is a top-of-the-range model that has it it's ruled out as AFAIC.

[gldgti]

Well, I think its a bit of an overreaction to say its a nightmare of added complexity and unreliability. Its another system that can go wrong - its more that the system forms part of the suspension and so if it does go wrong, there could be 'no drive home with it broken' results - same as any other part of the drivetrain.

I was dissappointed with the car for the 5-6 hours before I finally fixed it, at which point I fell back in love with it again for all its awesomeness. I find it hard to imagine ever going back to a car without air suspension after this (talking family car sized - its not a requirement for me on a hatchback).

There are nearly no factory air suspension vehicles with a good reputation, and interestingly, nearly every factory air ride car in the world seems to use this same WABCO compressor.... to name a few:

> All VAG air ride cars inc Porsche
> All Volvo air ride cars
> All BMW air ride cars
> All merc air ride cars
> All modern Range Rover/Landy with air ride

And I'm sure others that I dont know about.

Heres a pic of the commutator - this is before I'd done any work on it, but you can see ehre the armature windings attached to the commutator bars - in 2 places it had simply cracked.

[gldgti]

big thanks to anthony--t for giving me a hand today adding resonators to the exhaust. Took us about 2.5 hours but got the job done right and now the tips are sitting pretty, sound is sweet and the droning has gone - no more baffles at all - WIN!

[anthony--t]

Woohooo!!

[Idle]

Well, I think its a bit of an overreaction to say its a nightmare of added complexity and unreliability. Its another system that can go wrong - its more that the system forms part of the suspension and so if it does go wrong, there could be 'no drive home with it broken' results - same as any other part of the drivetrain.

I was dissappointed with the car for the 5-6 hours before I finally fixed it, at which point I fell back in love with it again for all its awesomeness. I find it hard to imagine ever going back to a car without air suspension after this (talking family car sized - its not a requirement for me on a hatchback).

There are nearly no factory air suspension vehicles with a good reputation, and interestingly, nearly every factory air ride car in the world seems to use this same WABCO compressor.... to name a few:

> All VAG air ride cars inc Porsche
> All Volvo air ride cars
> All BMW air ride cars
> All merc air ride cars
> All modern Range Rover/Landy with air ride

And I'm sure others that I don't know about.

Heres a pic of the commutator - this is before I'd done any work on it, but you can see ehre the armature windings attached to the commutator bars - in 2 places it had simply cracked.

You'll probably have to fix more of them over time.

Looks like designed-in metal fatigue — the wire angles don't seem right.

[gldgti]

I've considered that possibility. If it ends up like that I will solder them all I think.
Have you experience rewinding armatures?

[Idle]

No — armature winding isn't exactly an amateur sport... It's just that running and fixing machinery for 75+ years gives you an eye for what doesn't seem right.

Those wires look too rigid for their short length — the flexing from constant heating and cooling is almost guaranteed to eventually crack most of them.

Such a motor will usually run until the commutator fails (might wear out several sets of brushes before that happens.)

Incidentally, the weakest point on your repaired wires will be the solder joint.

[gldgti]

Yes I'm aware of that too. As far as I can see the windings are fairly typical of this type of DC motor. Anyway, I'll see how it goes.

[anthony--t]

This is just for the compressor yeah? Worst case scenario if it continues to be a headache wire in a viair like what every other aftermarket air setup runs. Shouldn't be a big deal.