fuel pipe size

[DVR V8]

Hello. Just replaced all the 5/16" rubber fuel hoses to R9 spec and want to replace the other two short lengths between the tank and the fuel pump. Just need to know the internal diameter . Kind regards.

[DVR V8]

Hi. All done thanks. Looked at technical data of bosch pump. Outlet 8mm, input 12mm. Cheers.

[bomb]

can you specify what lengths you needed please ? A full description would be appreciated.

[DVR V8]

Hi this is the second time i've changed the fuel hoses in 15years due to finding cracks but i have not changed the larger bore pipe from tank to pump. i would say less than half a metre is required [12mm inner, 18mm outer]. Also plan to get rid of the short brass tube for a proper hose connector. Regards.

[scottliv]

How much 8mm/ 5/16th R9 hose did you need? Would 2m be adequate?

[DVR V8]

I ordered 4m of Mocal R9 from Demon tweeks. I used a longer length for the feed to the fuel rail to get rid of joint behind the plenum/top of gearbox which is a pig to get at, then fitted high temp protective sleeving as being close to exhaust. Had some left over so used that to replace the coolant hose between header tank and expansion tank. So if you kept eveything as is probably 3m should do. Allow 1 m for the 2 pieces to the fuel rail, 1m for the return, RHR chassis through the body to top of tank then 1m for the 2pieces either side of the fuel filter. Hope this is helpful. Regards.

[scottliv]

That is great thanks.

[Steve_D]

DVR V8 said:

....................... Also plan to get rid of the short brass tube for a proper hose connector. Regards.

What sort of connector do you plan to use?
Bear in mind that the Brass 'hump' tube is there to allow the pipe to clear the suspension movement.

Steve

Edited by Steve_D on Thursday 27th August 21:46

[DVR V8]

Hi Steve. Yep, on closer inspection will probably have to abandon that idea.

[Simon.b]

Good post that, will put this on my list for jobs to do over the winter.

[scottliv]

Very timely post this. Only had my car 2 months. Had a fresh MOT. Checked the near side with the pump etc. All good as were the 2 in the engine bay. I was out in the car today and when I got back there was a steady drip of fuel from the return line. Waited for the exhaust to cool with 3 extinguishers on hand. Now not going to run the car until I have replaced it. Does anyone know how hard it is to do the connection on the fuel tank for the return hose? Does the tank need to detached and rocked backwards?

[DVR V8]

Hi. You don,t have to drain or remove tank completely. Remove the carpet above tank to reveal 2 10mm nuts. At the base of the tank there are 2 M8 bolts to remove. Then you can just pull the tank out on the RHS about 4inches to carry out the job and check for leaks before refit. Hope this helps. Regards.

[scottliv]

That is fantastic news. I was hoping someone would confirm this was the case. Going to get some Cohline hose and get the job done as soon as possible and get back on the road.

[lancepar]

Be aware that the fuel tanks on the very early precats have slightly different in and out locations on the tank, as when recently resealing my gauge sender I can't recall where the return pipe was on the tank.


https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Steve_D]

You should be able to replace the return line without moving the tank. The tank must not be full as the return is a couple of inches down from the top.
It is a fiddle but possible particularely if you have some very long longnose pliers.

Did one late last week.

Steve

[scottliv]

The return hose goes into the boot behind the driver side rear wheel. It then goes up behind the tank and terminates on a spigot about 6 inches from the top. Hopefully I can get to the old hose and pipe clamps from the side. If not hopefully I can move the tank enough to access it. Going to get Cohline FI R9 hose and mikalor clamps. Will also do the supply side even though it looks newer.

[scottliv]

Also I may add an off cut of larger bore hose to protect it as it sits on the suspension. It does not have the brass bridging pipe like the supply side.

[Aussie John]

I extended the copper lines up to near the fuel rail and return as one of the copper to flexible joins was pretty-much impossible to get at; I cut the original pipes back and joined using 8mm compression fittings, looks ok so far but a trip to Scotland in a few weeks will test it.