longevity of pneumatic locking system (B5 A4)

There are a lot of type 44 owners (1984 - 1991) that have pneumatic locking systems. They rarely have problems and seem to last the life of the car which on some of these is now around 300K miles. Once in a while there is a question on the forums but it is rare.

Tony '91 100Q 5spd

107K and locks are just f> My car: 1999.5 A4 2.8Q US model, will pass 75k miles tomorrow. Runs > great.

They last forever. If it develops a leak, the pump runs for 30 seconds and shuts off. A couple of years of this neglect seems to wipe out the pumps. It is a maintenance-free, very reliable design. I rarely change parts on a car under 10 years old. Mercedes used a similar system, same results. It's a non-issue. At 75K, I'd worry about the timing belt, not the locks. While you're there. fix that damned oil leak at the timing adjusters.

Good news. Whoops, I passed 74k today, not 75k. And top posting rules.

My '85 4000Q had 315,000 miles on it when I sold it. The pneumatic locks still worked great. Any trouble I did have could easily be located by finding the hissing noise. I don't think it gave me any trouble in the 10 years I had the car.

My wife's 94 jetta had the same system. It's only trouble was that the hose in the rear door-jam came pulled out of the connector once. So, I had to glue it back in.

I would much rather splice a split hose in a door jam than repair or replace a bundle of broken, shorting wiring harness!

From and engeering perspective, the pneumatic system is much less complicated, much, much lighter and more reliable than big clunky solenoids and switch contacts!

Gene