Fuel Pump Replacement

[BluesTraveler]

Had the fuel pump on my 04'GSA quit on me the other day at freeway speed. Pulled the tank and took it out this afternoon and preformed a bench test. At first it wouldn't work then on a third try it ran for a couple of seconds. Took it off the mounting plate, tapped it with a very small rubber tipped mallot, hooked up the power and it ran like nothing was ever wrong. Put it all back together and made a few trips around the neigborhood. Seems all fixed but Im sure it will do it again.

 

This is the same pump that took me about 2200 miles a little over a month ago with a clogged/restricted fuel filter. Remember the thread? I feel this could be the reason for early failure or is 55,000 about it for the stock pump.

 

What I was wondering is there maybe another aftermarket fuel pump that doesnt run $200-$250 that wil work. Is the BMW part the only opption?

 

Thanks in advance,

[Chris K]

Beemer Boneyard has an alternative HERE

[BluesTraveler]

Thats seems to be what Im looking for. Made in the USA and even comes with a new filter sock for about half the price.

 

Has anyone tried one of these kits yet? Just curious how it compares with stock.

 

Thanks Chris

 

Whats everyone opinion on trusting the stock pump until I get the new replacement?

[Dances_With_Wiener_Dogs]

You might conside relocating the filter to the outside of the tank. Do you sispect that the pump is failing or that there is sediment getting caught in the filter? From your description it sounds like the latter. Moving the filter isn't difficult and might be just the ticket.

 

Do a search and you'll find lots of posts on the subject.

[RFW]

You might conside relocating the filter to the outside of the tank.

Not a good idea!! It is not put in the tank because it is a handy place to mount it... It is in the tank for safety. Any leaks or burst filters (not unknown!) will not pose a hazard if the pump and filter are left in the tank.

[DavidEBSmith]

We've already had this debate, but your odds of the filter bursting are about the same as the odds of having a filter get clogged - so small that they're impossible to quantify.

 

As far as leaks, the number of people who've experienced leaks from the stock quick disconnects dwarfs the number of people who've experienced leaks arising from mounting the fuel filter externally.

 

Of course, I'm much more dismissive of the risk posed by mounting the fuel filter externally since one of the lines on my stock BMW fuel regulator manifold cracked and started spewing fuel on the catalytic converter. There have been more documented instances of the plastic fuel manifold failing than there have been of external fuel filters failing, and nobody freaks out about that potential failure.

[BluesTraveler]

I put a new filter in about 3000 miles ago so I doubt its the filter. When buying the new filter I asked the service manager at he Beemer dealership about relocating it as mentioned. He gave the same replay as to possible failure and how being inside the tank is a good place for it too leak. He did say the several owners were putting them outside the tank using some kind of high presure inline Honda filter with good results.

 

The first time going into the tank was a little un-nerving but after the second time its seems to be no big deal. Will get even easier once all the relacement clamps are all in place. This isn't something I'd want to do on a picnic table on the road as I have no idea what I'd do with all the fuel while getting the job done.

[RFW]

We've already had this debate, but your odds of the filter bursting are about the same as the odds of having a filter get clogged - so small that they're impossible to quantify.

Well, as it turns out, mine clogged so badly that the pump started whining like a banshee! I connected a pressure gauge and the reason for the noise became suddenly very clear. The pump pressure had risen from the normal 40psi or so, to way over 120psi!!! YIKES! I measured close to 100psi pressure drop across the filter!!! Replacing the filter immediately stopped the pump noise (the poor pump was struggling valiantly to push the fuel through the clogged filter, and "complaining" loudly in the process!). Once the filter was replaced, system pressure dropped back to normal again, with only about 1psi drop across the filter.

 

This was caused by a bad batch of gas I got in a rural area. The old filter was clogged by a lot of flour-like dust.

 

So as for the odds of this happening? I don't want to hear that it is "impossible"! If the pump and filter had been outside, and the filter burst, or a hose blew off its fitting, all hell would have broken loose.

 

By the way, BMW actually had its filter manufacturer (Mahle/Knecht I believe) modify the filter design, as a result of incidences of burst filters that were reported. In this case, the problem was caused traced to the part number and BMW logo etc. being embossed into the aluminum filter housing. Now this info is screen printed on instead.

[BluesTraveler]

Well, as it turns out, mine clogged so badly that the pump started whining like a banshee! I connected a pressure gauge and the reason for the noise became suddenly very clear. The pump pressure had risen from the normal 40psi or so, to way over 120psi!!! YIKES! I measured close to 100psi pressure drop across the filter!!! Replacing the filter immediately stopped the pump noise (the poor pump was struggling valiantly to push the fuel through the clogged filter, and "complaining" loudly in the process!). Once the filter was replaced, system pressure dropped back to normal again, with only about 1psi drop across the filter.

 

This sounds like what mine did on day two of my 8 day trip up north and back along the pacific coast. Actually started a topic here in hopes I would have an idea of what was going on with the bike. After answering many question everyone one here was pointing towards the filter and everyone was right. On start up I had a high pitch whine coming from under the tank. Sounded like a brake servo sticking only I could hear the servo's power up over it when I applied the brakes. And only whined when the engine was running. Trip was a little over 2800 miles and all but the first 500 of those miles I could hear that whine. Bike had around 52,000 miles and was still on the original fuel filter. I did no pressure tests but replaced the filter when I got home and the noise went away. The removed filter? I tried to blow through it and was supprised the bike was getting any fuel at all. Im curious and would not be supprised if this strain on the pump shortend its life. I will be sure to change the filter as required from now on.

 

But once again, after a few little tapes on the pump while out of the tank it is working once again. I'll feel better when a new ones in place but it is working again.

[RFW]

Im curious and would not be supprised if this strain on the pump shortend its life.

Don't worry about it. The pump is a roller cell pump. The rollers and housing they rotate in are hardened steel. The only real strain is that the motor was working harder, which would mean slightly increased brush wear, and higher internal temperature. But the pump is immersed in gasoline, which is an excellent cooling medium.

[DavidEBSmith]

So as for the odds of this happening? I don't want to hear that it is "impossible"! If the pump and filter had been outside, and the filter burst, or a hose blew off its fitting, all hell would have broken loose.

 

First of all, please read again what I wrote, carefully. The odds are small and impossible to quantify. I didn't say it was impossible, I said the odds were small and nobody knows what they are.

 

Second, the filter didn't burst, did it? And no hose blew off, did it? So whose point does your experience prove? Neither, because it's a sample size of one.

 

In fact, wouldn't it have been easier to change the clogged filter if it was outside the tank than if it was inside? Or even, to replace the filter more frequently to reduce the chances of it clogging?

 

And last time there was an argument over mounting the fuel filter externally, didn't the anti- side argue, essentially, that fuel filters never clog because modern fuel is so clean and filtered at the pump and you shouldn't ever have to worry about it?

[keithb]

Were you able to locate a new filter B.T.?

[BluesTraveler]

Hi Keith,

 

You mean did I find a new pump? Well Im going to go with the aftermarket pump kit from Beemerboneyard.com. North County wants $251.68 out the door and I still need a couple of their $3 clamps and a new sock filter. The aftermarket kit comes with everything for $139. Haven't ordered it yet as I was laid off about 3 weeks ago and still waiting on my 1st unemployment check. Money will be tight around here till I find another job. The bike is running and as long as I stick close to home I guess I'll be OK. Still wondering what caused it to stop working.

[keithb]

Yes I meant a new pump. Mike at Beemerboneyard is good peeps. Sorry to hear about the employment situation. Good luck securing another job.

KB

[RFW]

In fact, wouldn't it have been easier to change the clogged filter if it was outside the tank than if it was inside? Or even, to replace the filter more frequently to reduce the chances of it clogging?

No, not really. All I had to do was remove 4 screws to get the filler cap off the tank, then reach inside and undo the 2 hose clamps on the filter, remove the filter and put in a new one. It took 10 minutes. Nothin' to it! If it were external, then I would likely have had to remove some parts of the fairing, which would have been more of a hassle.

[Joe Frickin' Friday]

In fact, wouldn't it have been easier to change the clogged filter if it was outside the tank than if it was inside? Or even, to replace the filter more frequently to reduce the chances of it clogging?

No, not really. All I had to do was remove 4 screws to get the filler cap off the tank, then reach inside and undo the 2 hose clamps on the filter, remove the filter and put in a new one. It took 10 minutes. Nothin' to it! If it were external, then I would likely have had to remove some parts of the fairing, which would have been more of a hassle.

 

I see you ride an 86 K100RT. THe situation is different on oilheads, particularly the RT. To replace an in-tank filter, the tupperware has to come off, and the fuel tank must be removed from the bike to access the sending unit on the inboard face of the right tank lobe. If you happen to have a full tank of fuel at this point (as is likely, if it's a bad batch of gas that's plugged up the filter), it can be a challenge to do this without spilling a lot of fuel on yourself.

[BluesTraveler]

Well the Aftermarket kit is on the way. Total cost from Beemerboneyard.com including shipping was $149. When I do the swap i'll take pictures and show what the differance is between the two. Mike at B.B.Y. said there was a small differance in size but came with everything to make it work.

[russell_bynum]

In fact, wouldn't it have been easier to change the clogged filter if it was outside the tank than if it was inside? Or even, to replace the filter more frequently to reduce the chances of it clogging?

No, not really. All I had to do was remove 4 screws to get the filler cap off the tank, then reach inside and undo the 2 hose clamps on the filter, remove the filter and put in a new one. It took 10 minutes. Nothin' to it! If it were external, then I would likely have had to remove some parts of the fairing, which would have been more of a hassle.

 

I see you ride an 86 K100RT. THe situation is different on oilheads, particularly the RT. To replace an in-tank filter, the tupperware has to come off, and the fuel tank must be removed from the bike to access the sending unit on the inboard face of the right tank lobe. If you happen to have a full tank of fuel at this point (as is likely, if it's a bad batch of gas that's plugged up the filter), it can be a challenge to do this without spilling a lot of fuel on yourself.

 

What Mitch said.

 

It's a MUCH bigger deal to change the filter on an oilhead than on an old K-bike. (I've had both, so I can speak from experience).

 

Regarding the "filter outside the tank is bad because the filter could burst" argument:

 

Most of the fuel injected cars that I've owned have had the fuel filter outside of the fuel tank. Why is a burst filter not a concern on a car?

[RFW]

Most of the fuel injected cars that I've owned have had the fuel filter outside of the fuel tank. Why is a burst filter not a concern on a car?

The point is taken about my K100 being easier to change is in-tank filter than some other bikes. As for the difficulty of removing gas from a full tank, I never had that problem, since all I did was siphon it out into a bucket. No big thing.

 

Regarding the question above, about why an external pump/filter is not considered a problem on a car, all the fuel injected cars I have had, did indeed had an external filter/pump. But the filter and pump were located under the rear of the car by the tank, not on top of the motor where spillage would be far more "exciting".

[Lucas2Bosch]

This may sound a little off subject, but while you are talking about fuel.....and pressure....

On some Hot Rod Cars with fuel injection, they have a small liquid filled aftermarket Fuel Pressure Gauge mounted to the fuel rail. I also saw a place that one might install it on an R bike between the fuel hose and the plastic fuel rail with a "T"ed "AN" Male Connector. The round part of the gauge would fit nicely under the rounded spot where the line goes up to the injector on the right side. Has anyone ever seen a fuel pressure gauge mounted full time on these bikes?

[RFW]

Has anyone ever seen a fuel pressure gauge mounted full time on these bikes?

I installed one on a car I had 30 years ago (a VW with the first Bosch D-Jetronic electronic injection).

[BluesTraveler]

Pump showed up this afternoon and I pulled tank and took her all apart once again.

 

The new pump is just a little smaller than stock. Install went very smooth. Total time was about 1 1/2 hours. All I needed for my install was 2 of the wires,2 hose clamps, and the longer piece of rubber fuel line. Un-soldered the stock wires and replaced with new ones from the kit.

 

 

 

 

Swap went very smooth and cost was only $149 total.

[Ken H.]

Great pictures! Thanks for taking the time to do and post them.

[8uLiebr]

My '02 r1150rt (14000 mi) recently developed a new whine. It's not coming from a brake servo motor. Are there any other electric motors on the bike besides these mentioned and the fuel pump that could be making the noise?

[Ken H.]

My '02 r1150rt (14000 mi) recently developed a new whine. It's not coming from a brake servo motor. Are there any other electric motors on the bike besides these mentioned and the fuel pump that could be making the noise?

Nope.

[NoHeat]

How about the windshield motor?

[T__]

My '02 r1150rt (14000 mi) recently developed a new whine. It's not coming from a brake servo motor. Are there any other electric motors on the bike besides these mentioned and the fuel pump that could be making the noise?

 

Nelson, not really a motor but the alternator can make a few different types of whining noises.. The alternator noise will be engine RPM related & change with engine speed..

 

Twisty

 

[8uLiebr]

I'll check for alternator noises and windshield motor but the clogged fuel filter seems the best explanation. It could also account for the surging I've noticed lately.

[8uLiebr]

So a new filter is going in. I have everything disassembled and I'm ready to install (internally) the new fuel filter. While I'm in there I want to replace the internal pressurized fuel hoses with the appropriate hose stock purchased from NAPA -- who knows when I'll have the tank taken apart again?

 

But wait! The piece of outbound hose on the top of the filter has a tight little 180 deg bend in it. Trying to put that bend into the replacement hose produces a nasty kink that would probably restrict fuel flow at least as much as the clogged filter does.

 

My options:

1. Use a longer section of replacement stock.

2. Find a way to bend a short replacement piece without kinking it.

3. Buy a replacement BMW part 16142325808 (A&S only charges $37.16 each).

4. Reuse the original U-shaped hose. It looks ok & has only 14k miles on it.

 

Assessment of options:

1. This further increases clutter in the tank. Would it even fit?

2: Suggestions anyone?

3: Check eBay and CraigsList. This is one pricey little tube!

4: This is the way to go. With only 14k on the bike, the existing tube should have plenty more miles on it, right? Any reason why I shouldn't choose this approach?

 

[smiller]

I'd re-use the original, lesser of all evils. And just checking, by appropriate fuel hose from NAPA I assume you mean the special gasoline submersible-rated stuff? Expensive, but the way you must go for in-tank use.

[8uLiebr]

(See this post for an explanation of how to link to picacsaweb images.)

 

 

Here are the pictures that didn't display in my earlier post.

 

Exploded parts from A&S fiche:

 

The kink I'll get if I just bend the replacement hose:

 

Using a long piece of hose avoids the kink but probably takes up too much space.