I am replacing heater pipes behind dash but this upper one that i removed appears to serve no purpose and its not in any parts books. Air intake? Can someone enlighten me please.
It‘s the heater valve pipe.
Martin
If you look at the parts book you will get a good idea of how the water pipes go in……… similarly look at the vacuum pipe diagram as well….if you are in USA then you will also have 1 vacuum pipe if a RHD you will have 2 …. That all need to be fitted behind the dash ……further more you need to mix and match as you go in order to get them all in …. I’ve forgotten the sequence because it is a while Since I did it last
I notice that you appear to have the wiper linkage mechanism in the ( based on the knob poking through the firewall) cavity …if correct that is so … unless you remove this you will be VERY unlikely to be able to replace the pipes
Bob, that is an incomplete pipe, for whatever reason. Here is on of many threads reg. pipes, this will help:
I‘ve forgotten the sequence as well - funny how I recall some things quite well, other things less pleasant not so much 
That pipe you show is scrap, you‘ll need a replacement. Check the archives,
(and youtube) plenty material shown.
Martin
Martin it’s so painful …that like childbirth you forget all about it……until you do it again! 
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I looked at parts diagram and i have 4 pipes and the little short pipe sits above the lower pipe at heater box and does not show in diagram
Look carefully/ The diagrammed pipe has two bends, in the photo, yours has only one
John North
S1 Roadster
I have the three pipes in diagram with proper bends and then the 4th one in photo… hence mystery pipe
Seems to be some confusion here. Maybe this photo will help resolve it. The red pipes are the heater pipes, and the yellow one is the vacuum pipe (for LHD cars). A second vacuum pipe (directly above the first) is required for RHD cars - shown as a dashed yellow line. The water valve connects between the two shorter heater pipes.
I think i get it now. The upper right pipe is my short pipe. Apears to be missing other half of pipe. Have to pull down box with heater control to see if it was a flexible line behind. This is what happens when you take your car apart and don’t get back for several years and you start to loose your once sharp memory
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