As long as I have the fuel tank off...?

[MIbrick]

Put about a hundred miles on Monday, stopped for gas 10 miles out, drove home and parked the bike in the garage.  Next morning, when I left for work, nothing was amiss.  At lunch time, there was a distinct odor of gas and my garage was full of fumes, with a puddle under the bike. Weird, but what can you do?  I managed to get the tank off today and don't see any obvious holes or cracks. The fuel lines, however, are heavily cracked (if you grab and bend or twist, they open up like nets; cool!), which is maybe not surprising considering they're the originals on a 31 year old bike.

I'm hoping it was just the fuel lines giving way and seeping gas out, and not some unseen leak in the tank itself.  Still, funny it would start so suddenly.  I intend to get a new gasket for the outlet nipple (bottom, front left of tank), the complete gasket set for the tank lid and new fuel lines (obviously) between the tank-fuel rail and tank-pressure regulator. 

Couple of quick questions, though...

• Does anyone sell the fuel lines I need in pre-cut lengths?  Probably more expensive, but..easier. :)
• Can I reuse the BMW-branded screw clips that were on the tank ends of the fuel lines?  I haven't gotten to the end on the pressure regulator, but I assume it's the same style; how about that one?
• Is there a quick and easy way to check the tank for leaks, now that it's off the bike?
• I still have the flapper on the gas cap; what a PITA. Any danger in removing that?  What about that line that runs from the front right of the tank to the engine top (has a check valve in it)?
• As long as I have the tank off, what other preventative/routine maintenance would you recommend I be doing?

It's going to rain here for about the next week, so it's as good a time as any, I suppose, to work on the bike.

Thanks in advance!


Edit to add:  I'm also going to have to replace the insulation blanket from under the tank. The bottom one and the one closest to the fuel nipple/fuel lines on the left were completely saturated with fuel.

[Martin]

It's cheaper to cut the hose yourself, I get three changes out of a metre the short piece is 50mm long. One foot of hose is just long enough. You need to use fuel injected rated and submersible hose. Fuel hose clips are not the normal hose clip worm drive type which damage the hoses. To check for leaks fill it up with a gallon and check the lower seams, look for bubbles, blisters which are the first signs of impending leaks. Probe blisters carefully with a needle to check. Remove the flapper not fitted in OZ. Remove the pump and clean the screen replace if damaged. Replace all external lines and flush out the fuel rail, and either remove the injector screens and replace or back flush them.
Regards Martin.

[K1300S]

and that...is why any rubber more than 20 years old on a bike or car must be replaced.  all of it.  fuel, brake, coolant, air, vacuum...all of it.  not doing so is just playing the lottery on when they will crack, break or burst.

bmw will sell you all the fuel lines...but 5/16in HIGH PRESSURE FUEL INJECTION HOSE (not the low pressure stuff for carbs) can be found at any auto parts store.

only piece i would suggest getting from dealer is the low pressure return hose from regulator to tank.  it has several prebent curves and an insulator.  generic hose has hard time making those bends without kinking.

[MIbrick]

only piece i would suggest getting from dealer is the low pressure return hose from regulator to tank.  it has several prebent curves and an insulator.  generic hose has hard time making those bends without kinking.

If I'm on the MaxBMW Parts Fiche, is the pre-bent line+insulator you are referring to:


"13_0515 - THROTTLE HOUSING ASSY/CONTROL UNIT", Item #8 "Hose" with BMW Part 13 31 1 461 011


-or-


"13_0514 - FUEL INJECTION SYSTEM/INJECTION VALVE", Item #2 "Fuel Hose 8x13mm (meter)" with BMW Part 16 12 1 180 409 and Item #13 " PROTECTIVE HOSE - 330MM " with BMW Part 13 53 7 666 005


I'd guess, from the pictures, it's the first one (with the bend at each end pre-cast into the tube). But, that fiche doesn't show a protective hose along with it.


 

[Laitch]

I'd guess, from the pictures, it's the first one (with the bend at each end pre-cast into the tube). But, that fiche doesn't show a protective hose along with it.

I'll observe here that mlytle has a K75 and you have an early K100RS so it is likely that the parts might differ in appearance for similar applications.

[MIbrick]

I'll observe here that mlytle has a K75 and you have an early K100RS so it is likely that the parts might differ in appearance for similar applications.

Ah, I didn't catch that. 


Is there any special BMW) requirements for the coolant overflow hose (goes between radiator and overflow jug)? That's pretty damned cracked, too.  What about the various vacuum hoses?  Or can I just get 'standard', appropriately sized hose and replace those as well. 

[BrickMW]

If I'm on the MaxBMW Parts Fiche, is the pre-bent line+insulator you are referring to:


"13_0515 - THROTTLE HOUSING ASSY/CONTROL UNIT", Item #8 "Hose" with BMW Part 13 31 1 461 011


-or-


"13_0514 - FUEL INJECTION SYSTEM/INJECTION VALVE", Item #2 "Fuel Hose 8x13mm (meter)" with BMW Part 16 12 1 180 409 and Item #13 " PROTECTIVE HOSE - 330MM " with BMW Part 13 53 7 666 005


I'd guess, from the pictures, it's the first one (with the bend at each end pre-cast into the tube). But, that fiche doesn't show a protective hose along with it.

It is the first one. That line (fuel return - regulator to tank) doesn't have any protective sleeve or hose.


For the second diagram you cited.. I don't use the "protective hose", just standard 5/16" fuel injection hose for that location (high pressure - tank to fuel rail) This protective hose may be a more important item with your fairing. :dunno


The connections at the fuel pressure regulator will be one time use clamps (item 6 in your first diagram) that will have to be cut off and replaced with either new one time clamps or fuel injection adjustable hose clamps, make sure they are 100% stainless. Feel free to re-use your BMW adjustable clamps as long as they are in acceptable shape.


The hoses inside the tank have to be rated for submersion (the pricey stuff $$) and as Martin states can be found much cheaper than OEM from several sources. EME, Kbike parts, and Beemer Boneyard all offer "kits" for these if your looking for maximum convenience.


The crankcase line is not required. It was for California emissions. Read this "Side Note" just after 5b)...

[koapono]

If you still have the tank off now's the time to clean all those electrical connections that have been slowly oxidizing.
Some careful pulling and prodding will unravel the birds' nest of wires and give you access to most of the connectors.
Some de-ox (contact cleaner, various brands), Q-tips, brass bristle brush, pipe-cleaners, etc will make most connectors shiny as new.
Best to disconnect the battery before you start spraying de-ox and working brass brush across plug sockets and terminals.

Clean the ground connection on the frame and all the connectors that attach there.
Time and money well spent!

[MIbrick]

At this point here's what I've got on the docket:

• Replace all fuel lines
• Add 'air cup' and remove CA emissions vent tube (remove valve and plug hose going to engine block?)
• Replace fuel tank lid gaskets and outlet nipple (bottom, front, left of tank) gasket
• Replace vacuum lines
• Replace coolant hoses, radiator cap gasket, and sight tube on overflow (mine is blue at the top, opaque brown-black at the bottom!)
• Replace original brake lines with Spiegler stainless
• Inspect air cleaner (replace if necessary)

New questions:

• Is it OK to remove the tube from the bottom, right front of the gas tank and the check valve (the CA emissions stuff) and just plug that short tube going from the check valve to the engine block?  What to plug it with? If the recommendation is to take that hose off and plug at the engine block, same question: what to plug that with?
• I have a tube of Dow Corning 4 silicone electrical grease. I'm assuming after cleaning/deoxidizing all those electrical connectors applying a thin film of this before re-connecting is a Good Idea(tm).  Yes?

[Martin]

I grease all of my connections, a lot of Brickers don't recommend greasing saying it causes contact problems. I grease mine believing it keeps air and moisture out therefore reducing the chance of corrosion. I've had my Brick 20 years and the only problems I've had is with the one connection I didn't grease twice, it is now greased and behaving itself.  As far as plugging hoses I've used stainless cut down bolts in the past. While your delving into the tank check the screen on the bottom of your pump it can tear and develop holes. All my lines are just generic hose bought from an auto parts store, including the molded hose to the fuel pump regulator. If you find hoses kinking and flattening out on corners fit a stainless steel spring over the corner that is kinking. Larger hoses can have a spring fitted internally smaller diameter hoses externally.
Regards Martin.

[The Mighty Gryphon]

I also use that Dow Corning #4 silicone grease.  I figure it's ok for my bricks if it's FAA approved for aircraft electrical connectors.  As I recall, I got it online from a guy who sells stuff to airplane owners.

[koapono]

on electrical connectors I use a di-electric grease, available at most any auto-parts store.
My practice is to put a light "smear" across the top of female connector and then insert the male connector.
Sexual innuendo aside, this will lightly coat the internals and leave a nice seal at connecting point.
I've not had a failure of any connector thus treated.
The grease is secondary to a nice, clean and tight connection.
While you're at it, don't ignore all the plugs behind the right side panel: there are several two-prong connectors there just under the rear brake fluid reservoir.

[Martin]

While on the subject of grease, I also use heavy silicone grease under the boot of the rear master cylinder, and the entry into the front master cylinder as well as under the clutch push rod boot and under the fork dust caps. I clean and regrease every couple of years. The grease stops water and road scum from getting in. I haven't had to replace fork seals in 18 years and that's when I started doing it and I don't run gaiters. The rear master cylinder which I replaced with a Chinese one is still in perfect condition. Put one kit in the front master cylinder and have greased ever since. Replaced one clutch boot about five years ago and greased it on replacement. Iv'e now had the Brick for twenty years. Preventative maintenance saves you a lot of future trouble, I'd rather do work in the relative comfort of my garage than in the heat or rain on the side of the road. :riding:
Regards Martin.
 

[wmax351]

For my electrical maintainence, I pull all connectors, spray with PB-blaster or PB-catalyst, let it dry, then add some dielectric grease to both sides. The dielectric grease is not conductive, it's only purpose is to prevent corrosion. The connectors still need to be clean and contact each other, just like they would in air.


Fuel hose wise, I've actually found that the BMW dealer per-meter hose is equivalent or cheaper than the fuel injection hose at Oreilly's, etc. I'm certain it's higher quality too.