Type 44 diff lock check valve-location and generic?

[Phil Payne]

> Part diagram shows a check valve in the vacuum system that operates the
> differential locks. Anyone know exactly where this is located-trunk, console,
> undercar? Also is an Audi specific part needed, or are there generic check valves?

Black/white 1" cylindrical thing, usually in the engine bay attached to the firewall, but
sometimes under the rear seat on the left hand side.

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  Phil Payne
  http://www.isham-research.com
  +44 7785 302 803