High Pressure Fuel Hoses

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moto-m
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High Pressure Fuel Hoses

Postby moto-m » Fri May 19, 2017 10:11 am

I had to remove the fuel tank on a 1999 R1100R and had great difficulty pulling the fuel hoses off the rigid pipes and refitting them proved equally difficult - is there a trick to this that would help me next time. I did consider fitting some "quick connect" system but after reading that they could be unreliable I decided to stick with the original system - but I dread having to deal with the fuel hoses again when tank removal becomes necessary.
How do others manage it - I think this was the first time the tank has been off - so would new hoses be worth considering.
Mike
1999 Red R1100R
1998 Red R1100RS SE
1998 Black R1100R
1999 Graphite Metalic R1100R

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Galactic Greyhound
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Re: High Pressure Fuel Hoses

Postby Galactic Greyhound » Fri May 19, 2017 12:09 pm

Hi Mike,

The rubber fuel hoses can 'stick' onto the black nylon Regulator fuel pipes if they have not been removed for a long time.

If you were to remove your fuel hoses in the next month or so you would find that they now detach much easier.

It is MOST important when detaching the rubber fuel hoses that the black nylon Regulator pipes are not strained in any way otherwise they might kink or crack. The nylon pipes should therefore be well supported against movement when detaching the rubber hoses.

The method I use is to hold a nylon pipe steady with one hand while pushing off the rubber hose with the aid of pointed pliers against the end of the hose.

If the rubber hose has not stuck/perished onto the nylon pipe then the hose should come off fairly easily.

Alternatively, you might consider using a smear of Red Rubber Grease or Silicon Grease on the nylon pipes when fitting the hoses.
Do NOT use mineral grease which will expand and rot the rubber hose.

You were wise not to fit to fit Quickly Detachable (QD) fittings to your fuel lines which maintains a higher reliability of the fuel system at the expense of convenience.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" onclick="window.open(this.href);return false; - It works!

moto-m
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Re: High Pressure Fuel Hoses

Postby moto-m » Fri May 19, 2017 2:15 pm

Hi Ced,

Thanks for your reply - I've ordered new rubber hose as I'm pretty sure that these are the originals and never been touched and I thought that after 18 years it wouldn't be a bad thing anyhow - I'll try your method with the pointed pliers - I was holding on to the rigid pipe whilst pulling on the rubber hose with my other hand and it really didn't want to move - made me feel a real wimp. If the new pipes prove no easier to get on then I'll definitely try a little Red Rubber Grease - my worry was that it might impair the grip of the hose onto the pipe when I do manage to get it in the correct position even after tightening the clamp. I understand that the fuel in the pipe is under quite high pressure and I wouldn't want to be riding along and have the hose blow off.

Mike
1999 Red R1100R
1998 Red R1100RS SE
1998 Black R1100R
1999 Graphite Metalic R1100R

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Galactic Greyhound
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Location: Dumfries

Re: High Pressure Fuel Hoses

Postby Galactic Greyhound » Fri May 19, 2017 4:09 pm

Hi Mike,

Pulling rather than pushing on the rubber hose tends to stretch the hose and tighten its grip on the nylon pipe.

IIRC, the nylon pipe has a slight balloon section near the end which helps secure the hose from being blown off in conjunction with a properly positioned hose clip.

New external fuel hoses are not a bad idea given the age of the bike.

The Fuel Rail pressure maintained by the Fuel Regulator is 34 psi.
The TOP nylon pipe/rubber hose is the Regulator Return feed to the tank and this should be 2 litres/minute if the fuel supply system is working properly.
This Top rubber hose can be used to drain off most of the tank.

When you next do a Fuel Filter change it would be advisable to change the internal fuel hoses particularly the 'U' hose with the correct BMW parts as these hoses are to a special specification for hoses permanently submerged in fuel.
Failure to change these internal hoses risks having a hose split under pressure when they age.

I use the reusable Fuel Injection Hose Clips supplied by Motorworks (13mm nominal) to replace the standard Oetiker clips.
Ced.

R1100RT 1996.
Sent by Boson Quantum Transmission from the Starship 'Galahad'.
http://www.researchgate.net/publication ... ing_bosons" onclick="window.open(this.href);return false; - It works!

moto-m
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Posts: 32
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Location: Cheshire UK

Re: High Pressure Fuel Hoses

Postby moto-m » Fri May 19, 2017 4:35 pm

Thanks Ced - Very useful advice - I hadn't thought about the possibility of tightening the hose's grip by pulling it - I was concerned about damaging the hose by using any sort of tool on it - I've already ordered new clips from Motorworks with the new fuel hose so fingers crossed for an easy installation.

Mike
1999 Red R1100R
1998 Red R1100RS SE
1998 Black R1100R
1999 Graphite Metalic R1100R

sykospain
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Re: High Pressure Fuel Hoses

Postby sykospain » Tue May 23, 2017 11:52 am

Fuel line Quick Disconnects are not inherently unreliable, provided they are NOT the plastic BMW OEM parts, the male half of which snaps for fun. Evans sells the magnificent tit-ally metal pairs made in the USA by Jiffy-tite© - the best high-pressure-resistant fuel-resistant quick disconnect fittings you can buy.
And incidentally, for wrestling with vulnerable aged rubber piping or struggling with any rubber fitment, New Hampshire BMW expert wrencher Chris Harris, now looking ever more sickly in his latest U-Toob videos, recommends as the best rubber lubricant of all, surgical spirit, which the Americans refer to as Rubbing Alcohol, which leaves no residue.

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farmerboy
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Re: High Pressure Fuel Hoses

Postby farmerboy » Tue May 23, 2017 7:48 pm

I have just (today) replaced the plastic ones with metal.... sooooo much better!
2006 R1200 RT
Grey

2000 Cagiva Navigator TL1000S
Red

2015 Kawasaki Versys 650 LT
Green (kept in Texas)

John


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