Firstfives.org

There is a post on Bimmer Forums describing the process of installing a new pump, in tank sending unit/filter, fuel filter and lines.

I just did that, but according to me only a few fuel lines needed replacing. Everything else cleaned up nicely. A new in line filter was added. The fuel pump has never given any indications of deteriorating performance.

My question relates to the Bimmer replaced everything guy. His project assessment of a performance boost is so hyper,... you'd think he used turbo tune lines and a triple pooper upper pump.

So, experts out there, do pumps get puny ? Lose their ability to pump to spec ? Can the in tank sender, filter look clean as new but not be up to some spec ?

No offense, the whole whoopee ding performance excitement thing sounded like a sales pitch.

The fuel pumps usually work just fine up until they die because the brushes are worn out and they don't run anymore. If the filter looks ok it probably is.

Thanks Mike. Ever since I had an input shaft bearing fail, no noises to ignore, I like to have some idea of preventative maintenance procedures. Standing on the freeway waiting for the flat bed is too much time to ponder my being stupid.

I changed the filter to new, as it is a closed cylinder and difficult to see in the little holes to assess what the inside looks like. I assume if the pump brushes are failing they make warning noises to that effect before giving up.

Checking realoem.com, no offense, $ 394.00 is a dab spendy for just hauling off and replacing a probably good pump.

T.Hanson wrote: I assume if the pump brushes are failing they make warning noises to that effect before giving up.

Checking realoem.com, no offense, $ 394.00 is a dab spendy for just hauling off and replacing a probably good pump.

Nope, no warning noises, the brushes are suddenly no longer long enough and it just stops. Often you can get a few more miles with the whack of a screwdriver by reseating the brushes, but that's it. New pumps aren't always that expensive though, Amazon shows a Bosch replacement at $100 and knock offs even less.

A complete failure with no obvious noise, performance warning, plus 18 years of service,

I am choosing replacement of the system components. If I can find the OEM Bosh pump for $100 as opposed to $300, figure that is better spent than on a flat bed rescue, THEN buying the pump.

In the process of replacing, my assessment of at least the two braided large, slightly smaller fuel lines : A must.

The lines are wedged in place. There are tie wraps and tape holding them to the gas tank that must be located and removed. After that patience removing the dirt, finding the angles on top of the tank that allow the best slipping.

I removed two rear gas tank mount bolts using a floor jack for support. Lowering the tank slightly allowed the space for the lines to pull much easier.

Wrapping sticky black cloth racer tape 3" over each one using the old to pull through the new worked well.

Once out, the 35 year old braided lines failed the hard crunchy rubber test. The ends were prime for cracking and leaking.

Any of the original lines still in place should be accounted for. Especially the pressure/suction ones, but the evap ones too. Location makes a difference in the lifespan, but to me they're only good for about 20 or so, including the evap ones. I've done those 4 extra lines on so many 70s/80s BMWs I can't remember them all. All so I didn't have to smell gas.

BTW, it's an OEM pump, but I don't think the original roller cell pump is still available. No matter, other ones work too and it's more a technical difference than practical.

" Accounted for," to mean replace after 35 years. No big deal, providing one has a few 40 hours.
Beginning with removing the pinch clamps holding the old braid covered lines on the tank fittings and plastic canister. I mean after one takes the photos or makes the detailed drawings of where each line goes, ends connecting where, through the grommets, anticipating no way to get one's hands in the filler door to push, clamp the tank ends.
Do real BMW mechanics have the super sharp, big leverage handle side cutters required to, "snip," the squeeze clamps off ?
I did not. Instead I used a Dremel tool trying various ends. Concerning when removing the clamps from the plastic canister. Heat, because it took grinding the clamps all the way through. Never just thin enough to use a pliers to flex and break.
Installation is the reverse,... one *%# pain in the butt hose choice, no way using the pinch clamps again, tie wraps ?

With a good electricians quality wire cutter, I can cut them off. Perpendicular to the line, not parallel with it though. And occasionally in select locations I will work the crimp clamps loose, open them up some and reuse them. Not often, but sometimes a screw clamp just won't work. It's an afternoon, not a particularly pleasant one with crap falling in your face, but not very expensive at least.