j.kenzie@sbcglobal.net

Hi Guys,
I have been having some trouble with my one year old 5/16" F.I. hose with clamps. They get loose, and need tightening. I am talking about the 2" long hoses that connect the injectors to the fuel rail.
I did some research, and I understand the factory uses a metric size hose that is a very tight push fit, and covers that with a collar. Can anyone please tell me the hose size or number? I know from Greg, that clamps are not that good over these barbs. Are the collars really needed? Do they do anything?
Thanks, and Happy New Year,
Dave

BRB-83-911SC

I replaced mine with the proper metric hose and re-used the ferules (hats), no clamps, just like they did at the factory. Fit is perfect and leak free 3 years later.

See post 94 here:

https://rennlist.com/forums/928-foru...ml#post9911921

I think Roger may carry the hose in bulk, Greg Brown may also.

j.kenzie@sbcglobal.net

Thanks, Brian.
I ordered some N020 281 1 fuel line. I believe that is what Greg recommends. I think it is 7mm x 13mm.
Does that seem correct?
Dave

BRB-83-911SC

Yes, that sounds right. A Google of that Part Number brings up pics of what I used.

j.kenzie@sbcglobal.net

Thanks, Brian. I think I can get the ferrules from Roger.
Dave

ROG100

Dave - I am not so certain about N 020 181 1 as it is not even used on a 928 and at 7mm ID seems too small.
The correct Cohline hose is 7.5mm ID and the hose used on the regulator lines is 928 181 152 50 also 7.5mm ID. That is what Greg has mentioned in the past.

j.kenzie@sbcglobal.net

Thanks Roger,
I am kind of hoping that Greg will chime in. I have some 7.5mm, and I ordered some 7.0mm. I would really like to know what is proper. thus the title ofmy thread.
Thanks very much,
Dave

ROG100

Most important is the polyamide sleeve (veneer) on the inside of the hose as this is what Porsche used with barbed fittings. It is less flexible/expandable so diameter is important.
928 181 152 50 is just EFI fuel hose and does not have the veneer so "in theory" it can't be used with barbed fittings.

j.kenzie@sbcglobal.net

Thanks, Roger.
So what is the best replacement for these little hoses? I am not convinced that 5/16" hose plus EFI clamps is the solution, since for me they need constant retightening to fix leaks.
Dave

danglerb

I used Gates 27335 which is Calif CARB approved low perm FI hose with Norma clamps, but to do it over again, I would be done with barbed fittings and hoses and update to a modern Oring injector and rail.

ROG100

I have been using the EFI hose and clamps on my own cars (my choice my risk) with zero issues so strange that you have a repeating leak issue and for that reason you must change them.
Porsche sells a replacement hose and ferrules for $25 per injector. I am tempted to order a set to see what the hose is.

j.kenzie@sbcglobal.net

Hi Roger,
Maybe I didn't tighten down the norma clamps correctly in the first place. I have been afraid to overtighten and cut the hose, so maybe I created the problem of leakage myself.
Dave

ROG100

Dave - that is why you use special EFI clamps. The lip is turned up around the edge so it will not cut into the rubber no matter how tight you make them.

j.kenzie@sbcglobal.net

I was more concerned that the barbs on the fitting inside the hose would cut the hose from the inside.
Dave

ROG100

In theory that is what is supposed to happen but in practice it does not for some strange reason - do so at your own risk.
I just removed Wurth EFI hose from my GTS after about 9 years with zero issues and no cuts on the inside - indentations from the shape of the barbed fitting but no cuts. I replaced with Porsche/Greg's hoses.