I'm looking to trace all of my vacuum lines for the usual reasons. Does anyone know of a schematic that shows all of the lines. The "katalog" only shows those that are associated with a given function as far as I can tell. Or maybe I just don't know where to look?

 

Well, it would help if we knew which car you have. I have some layouts for a few of the cars. Which one do you need?

 

Someday I'm going to remember to indicate the car. It's a 1987 S4 with the five speed manual. Sorry for my blunder.

 

This one is more or less correct for an '87.

Exceptions:

Capital "I", the diverter valve, is over by the coolant reservoir

lower case 'e' doesn't exist on a 5-speed, that's the line to the automatic transmission

The vacuum line 'd' to the flappy solenoid 'K' connects to the 4-way splitter adjacent to the brake booster

 

This is very useful.

My only confusion is over 'F and 'I'. 'F' on my 87 looks to be part of the fuel vapor system which leaves 'I' to be the valve associated with air pump (which I have deleted)

Have I got the right?

 

Look at 928rUs website. It has a vacuum diagram with the tubing that they sell. Hope that helps.

 

That was great - it confirmed my assumptions.

 

Thanks guys. Old cars are a lot of work. Old Porsches are really a lot of work. Old 928s are an incredible amount of work - but worth it.

 

Thanks to OP, too.