Banjo fitting

[kavadarci]

Hi,

I got new fuel pump, fuel check valve and the bolt from Len.
When I tried to replace the pump I found the factory benjo fitting is small and doesn’t fit in the new fuel pump check valve. I do want to use the check valve as I have hot startup problem on the car.

What size benjo fitting do I need and where can I buy it from? Photos are from Duane, thank you.
Thank you

[Harpo]

Do you have verniers to measure the OD of your check valve and the id of the current banjo fitting?


David

[nickelplated5s]

Try a hydraulic shop, one that makes hose assemblies.

[RLJett]

When I bought my stuff from Len he needed me to measure the fitting on my fuel pump to provide the correct banjo fitting size as there are two sizes. Sounds like you have the smaller. I believe this is the smaller check valve (M10 versus M12).

https://www.pelicanparts.com/More_Info/91160821100.htm?pn=911-608-211-00-OEM&SVSVSI=808

[kavadarci]

I got the correct cap from Len. I think it’s m10.
The lug nutbis 17mm wrench.

[BoxsterGT]

Porsche constantly makes running changes and improvements to their vehicles, and in the 73 model year, with emission standards more strict, Porsche introduced the CIS Fuel Injection system to the 911.

The CIS system requires a Check Valve, and the original used with this was 10mm in diameter. Perhaps as an improvement to the system, in the 75-76 model years Porsche went to the larger 12mm size.

However, for one reason or another, in the mid to late 70's some models 911 and some models 930 appear to still have 10mm Banjos.

Perhaps it was a supply issue with Bosch, I don't know, but it is a fact that not all 76 on models have the 12mm Check Valve & Banjo.

In case you would like to know just what you actually have, the M10 Banjo has an OD of 17mm while the 12mm Banjo has an OD of 19.8mm.

Edit: These are not the wrench sizes but the actual OD of the respective Banjos.

Hope this helps. I have most all Fuel & Oil fittings including Banjos for a 911 in stock.

Len dot Cummings at verizon dot net

[MacD]

Fwiw - I have a 76 with the fuel pump up front. The fuel pump is the one with both the electric plug and fuel outlet on the side (the one that is currently $790 on this site).
The fuel pump started leaking around the body near the plug so I ordered the Bosch 69459. It comes with a check valve that is 12mm and the original banjo fitting is too small.That started much confusion about check valves and banjo fittings.
Turns out that original style fuel pump doesn't have a check valve in it as some info would have you believe. Apparently the check valve is in the 10mm banjo fitting. If you unscrew the check valve that comes with the Bosch 69459 you will find you can simply screw in the original Porsche hollow bolt and 10mm banjo fitting. With new copper crushwashers, of course.

[dap930]

I found that Porsche apparently changed the front pump in 1980 model year. I did an EFI conversion on my '77 930 and I wanted the larger banjo fitting at the front because I was lowering the fuel pressure for EFI verses CIS and I wanted to keep the flow rate up. I ordered the 1980 front pump which came with the 12mm check valve needing the 12mm banjo fitting and cap. I had Len make me new fuel lines and I specified that I wanted a 12mm banjo for the front pump verses the stock 10mm banjo. It all worked perfectly.

[Solamar]

Do you know the PN of your pump?

The correct fuel pump for my 78SC is Bosch PN 580-254-984. This requires a 10mm banjo and has an internal check valve (not in the banjo bolt). I believe you could adapt to 12mm, but you might wind up with two check valves. Looks like you have original fuel lines with a 10mm banjo.

The chart below notes pumps with the internal check valve with a (F) under outlet connection.

[Solamar]

You probably need these pieces if your fuel line has a 10mm banjo-

[BoxsterGT]

If you have a mid to late 70's 911 with the 10mm Pump & Banjo and are are replacing the pump, you may want to update to the later 12mm size.

Most European manufacturers use this Bosch flow-through design pump, and the 12mm size has become universal.

The early version Pump with 10mm Banjo is now much more expensive to buy and more difficult to source.

Of course if your Pump is still good and you need replacement lines, you can upgrade the check valve itself to 12mm as Solamar points out above.

This chart is a great resource.

I offer the Front Feed Hose with either size Banjo at no difference in cost, and the other related components (Tunnel Lines & Hoses) remain the same.

You can determine what you have without disassembly by measuring the Banjo OD. The M10 is 17mm and the M12 is 19.8mm.

Hope this helps.

Len.Cummings at verizon.net

[Johan.s]

Waking up this old thread since I need to replace some fuel lines and I was wondering if anyone can confirm if the the front feed line, article number 91135606607, has a 10 mm banjo? This part is suppose to fit 1978 to 1979 models.

[David Inc.]

I just took it off my '82 and can confirm the top bolt took a 19mm wrench. I have no idea what that means in terms of shaft size but...it's something?

[BoxsterGT]

Johan.s -

This really depends on the production date of your 911 and Porsches inventory at that date.

As stated above, Porsche makes changes at will, and between 75 and 77 model years they began using the Flow-Through Bosch Pump with a 10mm Banjo & check valve.

At some point near the end of this range of production they switched to a 12mm Banjo & Check valve.

Perhaps there was an inventory or stock issue, as some later 77 models had 10mm and some earlier ones had 12mm.

Only real way to know for certain is to measure the Banjo OD as stated above.


Edit:

By Model year 82 the Front Fuel Line Banjo and Pump had a M12 Banjo ONLY.

The wrench size for the 10mm Banjo & Bolt is 17mm. The 12mm Banjo takes the 19mm Wrench.

Len

[john walker's workshop]

I've used a tapered reamer to enlarge it to fit the check valve. A little on each side until it slips on, then carefully file the remaining edges smooth so they seal well against the copper seals. Not a lot of area left to seal, but it works if you're careful.

[Johan.s]

Sorry I forgot some vital information. My car is a 1978 911 3.0 SC.
The part I referred to, 91135606607, is suppose to fit 1978 and 1979 models. From 1980 to 1983 the part number is 91135606608.

Based on the dimensions of correlating banjo bolts my guess is that the 78 to 79 hose has a 10mm banjo and the 80 to 83 hose has a 12 mm banjo.

My car currently has a Bosch 044 fuel pump with an external check valve that requires a 12mm banjo. Currently the fuel delivery contains a normal hose clamp () which is a solution I'm not satisfied with. Ideally I'd like to keep the fuel pump but I'm afraid I will will end up with a hose with a 10mm banjo if I order the 78-79 part, 91135606607.

Initially I thought that perhaps I could buy the 1980-83 front hose and connect that to the 044 pump but then I discovered that the rear section of the fuel system is also different compared to 78-79.

[BoxsterGT]

Johan-

I seem to remember an email from you asking about this issue, and thought I replied but perhaps not. If so, my apologies. It's my age and habits getting the best of me.

The factory Fuel lines that run through the tunnel are one-piece with their respective Front Hoses.

They are crimped together, not separate parts.

If you want to save the effort of doing the full Tunnel line I offer my front Repair Hoses as here....



Alternately, I also offer my replacement full Tunnel Lines that have M14 Male Fittings at the front that connect to my separate Front Hoses...



My hoses are E-85 Rated and make for a more permanent repair that should last for the lifetime of the vehicle.

If this will help, please email me.

len.cummings @ verizon.net

[BoxsterGT]

Bringing this to the TOP.

Valuable info on Bosch Fuel Pumps here.

Len

[Walt Fricke]

Interesting idea to ream your 10mm banjo to 12mm. Saves replacing the entire fuel line, or alternately adding a hose clamp based connector.

[BoxsterGT]

This may work as a temporary measure, but the crush ring surface is marginal and not sufficient for a long-term fitment, IMHO.

Len