990 Fuel Pump Won't Seal

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Mikef5000, Dec 4, 2013.

  1. gefr

    gefr Life is a trip

    Joined:
    Nov 26, 2005
    Oddometer:
    4,615
    Location:
    East Med, Greece
    Thicker than 3.0mm. Also apply some vaseline when inserting. Seems you are really close.
    Cheers.
    #21
  2. sparwood_rider

    sparwood_rider Adventurer

    Joined:
    Mar 29, 2009
    Oddometer:
    10
    Location:
    Kootenays, BC
    24 hrs and no drips which is more promising than anything else I've tried.

    :D
    #22
  3. AlxT

    AlxT Adventurer

    Joined:
    Dec 4, 2012
    Oddometer:
    75
    Location:
    Chania, Crete, GR
    I recently changed the filters and used a handful of Silicon - base lubricant (that stated on the label that it doesn't react with gas or petrol) on the oring as well as the tank itself and pressed the pump evenly on two of its corners until it popped in. Also after it pops in there was a minimal play so I moved it just a tiny bit in out so that the oring sits right. BTW, didn't even have to use the new rings, the old ones were in perfect shape.

    Tapatalked @ sgsIV
    #23
  4. sparwood_rider

    sparwood_rider Adventurer

    Joined:
    Mar 29, 2009
    Oddometer:
    10
    Location:
    Kootenays, BC
    The 932 o-rings started leaking after 2 weeks. This was 2 days before starting out to ride the continental divide. I resorted to the Permatex 2 as mentioned above with the 932 (3mm dia) o-ring. I let it cure for 24 hours and then I smothered it like icing on a cake near the bolts and flange area. It lasted good enough for the 11 day 8000 km trip. It started leaking half way through the trip. The bike is currently parked outside because of the fuel leak. Will try the Permatex 2 again, but with a longer cure. I overfilled the tank many times which probably didn't help the Permatex since it was attacking it from the inside and outside.

    What other products would anyone recommend for sealing the flange?:eek1
    #24
  5. Margrave

    Margrave n00b

    Joined:
    Mar 5, 2007
    Oddometer:
    3
    Had the same problem last year with fuel dripping from the fuel pump front securing screw (at 48k and 6 years). My tank had also distorted, with the hole measured oval by .024" and the tank mounting bolts increasingly difficult to align.
    I tried new and larger o rings, DowCorning 55 seal lube and RTV under the flange - none of which fixed the leak for more than a week.
    I then obtained some aerospace high strengh fuel tank sealer, applied both over and under the annular and flange o rings and reinstalled the pump - being careful not to over-tighted the bolts. This fixed it.
    This 2 part mix sealant is manufactured by PRC-Desoto spec PR1770B (http://www.ppg.com/coatings/aerospace/sealants1/pr_1770_class_b.pdf).
    Managed to source some on fleabay.
    It cures to a very tough rubber consistancy and does allow (with care) subsequent removal of the pump.
    #25
  6. sparwood_rider

    sparwood_rider Adventurer

    Joined:
    Mar 29, 2009
    Oddometer:
    10
    Location:
    Kootenays, BC
    I'll see where I can source this product. It sounds more promising than what I've tried so far.
    #26
  7. rossguzzi

    rossguzzi 990 Adv.

    Joined:
    Oct 21, 2012
    Oddometer:
    1,562
    Location:
    Bottom left hand side of OZ
    How common is this leaking problem.

    Has anyone changed out a pump and not had a leak?

    Wondering if I should buy things to prepare for the worst.
    #27
  8. orangepeeler

    orangepeeler Adventurer

    Joined:
    Oct 11, 2009
    Oddometer:
    21
    Location:
    Flatlands of Colorado
    On mine I found it was one of the threaded holes in tank was cracked. I used longer bolts and permatex #2 on threads and flange. Still dry after a year and several thousand miles..
    #28
  9. sparwood_rider

    sparwood_rider Adventurer

    Joined:
    Mar 29, 2009
    Oddometer:
    10
    Location:
    Kootenays, BC
    Any idea how much longer the bolts you used were?
    #29
  10. orangepeeler

    orangepeeler Adventurer

    Joined:
    Oct 11, 2009
    Oddometer:
    21
    Location:
    Flatlands of Colorado
    Maybe 3/16" or less dont remember for sure. One bolt was partially stripped also and I bought bike new?
    I thought mine was orings too til discovered cracked messed up bolt hole in tank.

    Just came home from going thru your part of the world..beautiful country!!
    #30
  11. sparwood_rider

    sparwood_rider Adventurer

    Joined:
    Mar 29, 2009
    Oddometer:
    10
    Location:
    Kootenays, BC
    I broke down and bought the OEM o-rings. The annular o-ing a much larger diameter than the other o-rings I purchased. The diameter was 3.11. The biggest 932 I had found was 2.97. The larger diameter fit in quite easily into the fuel tank.

    I ended up replacing both sections of fuel line between the pump and the throttle body. Both were damaged with what looked like pin holes. They weren't leaking yet, but on their way. I broke the quick connect after removing it so many times. I changed that at the same time.

    I still had a leak. The fuel was coming from one of the four holes in the tank. I had previously used thread sealant tape for natural gas/gasoline. I tried thread sealant paste and it worked perfectly. It wasn't leaked in over 4 months. It has only been sitting in the garage though. We'll see how it works in the summer.

    I feel like I'm sandwiching the quick connect between the tank and the frame. I'm trying to figure out how to protect it. In the past, I have put gorilla tape over the connection as a backup for them splitting apart. This is different. It's stuck in a hard place. :clap
    #31