Auxillary air regulator hose, early 928

[928jr]

Hi Guys,

I am looking to replace the braided hose that leads off the back of the auxiliary air regulator of my car, mine is badly frayed.
I have found multiple diagrams that show the front hose that leads to the intake (928 110 177 02) but couldn't find one that showed a part number or picture of the the rear hose.
Thanks,
David

This is the system on my car looks like, part no (928 110 177 02) is listed as 43. Aux is no 5. Unfortunately the hose that leads off the back of the regulator is not listed.
Porsche 928 K-jetronic Parts

In the 80+ models it looks like it has an L shape, see part no. 23.
Porsche 928 L-jetronic Parts

Sorry for the bad quality picture, but I have put an arrow to the hose om my car here


Has anyone had to replace this one themselves or know which one it is?

Cheers

[MPDano]

This hose?

[MPDano]

the little one?

[928jr]

Thanks for helping me sort this out MPDano.

The little hose (21) looks to be the closest, the one I am trying to replace is straight and reasonably short, but that hose is connected on the other side than the one on my car. Is that diagram is for the regulator on a later version? I have a '79 and it doesn't seem the same.

The first diagram that you posted up has the same system as my car, the big curved regulator to distributor hose (one that you highlighted) sits on one side and on the other is a short hose.

I looked up in the forums and funnily enough the only reference that is clear enough to use is from a post you originally contributed on.. and btw If thats your car, WOW haha, mine will get there eventually though!!



I have highlighted where the hose should be located in this picture:

[MPDano]

Yes, that's my Euro. Let me look at that hose closer after work today. Rjm65 has a 79 and hopefully he'll chime in.

[Luis_M]

Hi, I can't scan in the pic where I am, but the drawing of the part you are seeking is on illustration 107-05 of the Euro/ROW PET PDF. Dano's pic with the "little hose" is from a US L-jet set-up, but it's the same part number. It's "cut-to-length" generic hose, #27, 999-239-009-40.

As an aside, the hose with the arrow on Dano's car with the blue silicone couplers (love those couplers, BTW!) is #27A on the same illustration, 928-110-357-00 (hose - air guide housing - auxiliary air regulator), and was a change for 1980+

Through 1979 you should actually have two pieces of that generic hose, one clamped to the back of the AAR, the other clamped to the appropriate port on the air guide, with a plastic multi-port T-piece in between them ("distributing piece" #32, 928-110-439-00). No clamps needed on the plastic piece, AFAIK. This distributing piece has 3 ports, one of which should be capped, one for the brake booster venturi valve, and one for the air-conditioner idle bypass valve. After 1979, the brake-related hose got its own separate port on the air guide.

Just cut pieces to the same length as the original for the two sections to replace. You could probably use any decent vacuum hose of the same diameter, since this hose is subject to vacuum, but it should have some tolerance to oil since some oil vapor will likely be present in the air that is being sucked up from the air-guide.

PS: Just realized that you probably have a RHD car. Your brake venturi routing may be different from what I've outlined above. I'd love to know....

[928jr]

Yep, that's the one! Thanks Luis! My car is stored 20K away so I'll have to check that venturi routing for you during the week.

Cheers guys for your help, I'm learning something new about my car everyday!

[Luis_M]

Here is the PET drawing...