Results 1 to 7 of 7
  1. #1
    Join Date
    Sep 2007
    Posts
    3,071

    Default Bleeding the fuel system-I dont believe it!

    I finally got around to reinstalling my fuel pipework from my twin tanks either side of the engine.
    Everything was piped up and taps turned on and everything seemed leak free.
    I unscrewed the bleed screw on top of the CAV filter-nothing!
    This was how it was when after cleaning the CAV filter a year ago I found diesel bug which I assumed was blocking the piping.
    I checked the bottom of tank exit fuel lines by loosening a union-fuel.
    I then realise that the 10 gallons I had put in(two 40 gallon tanks)was not enough to fill the tanks to the level of the top of the CAV filter!
    The system is tank to CAV filter to lift pump to onboard engine filter to injector pump.
    Having just added an emergency 2 gallon tank which sits above one of the tanks I can fill the filter from above with enough fuel to allow me to operate the manual primer on the pump.
    Without this I guess I could have messed about priming the filter through the bleed screw hole! and then used the lift pump primer.
    All Mercedes recommended for the fuel system for the OM636 was a simple gauze inline pump between the lift pump and tank with the heavy duty cleanable engine filter doing the fine filtering.

  2. #2
    Join Date
    Nov 2008
    Posts
    6,192

    Default Re: Bleeding the fuel system-I dont believe it!

    Dinghy pumps are marvellous things for slightly and temporarily pressurising tanks. For example, if my tanks are getting low, I can transfer all my fuel from one tank to the other with the dinghy pump. It only needs a bit of rag to temporarily plug the approriate air vent. I'm sure you could do similar to prime your filter.

  3. #3
    Join Date
    Mar 2015
    Location
    Isle of Eigg
    Posts
    6,053

    Default Re: Bleeding the fuel system-I dont believe it!

    Quote Originally Posted by ffiill View Post
    All Mercedes recommended for the fuel system for the OM636 was a simple gauze inline pump between the lift pump and tank with the heavy duty cleanable engine filter doing the fine filtering.
    Probably because the lift pump is not a finely machined high pressure precision variable volume pump, the injector pump on the other hand.....
    If it can fit though a gauze, it wont damage the lift pump.
    Just call me Dougal, Sir Dougal to you.

  4. #4
    Join Date
    Sep 2001
    Location
    Home - Sothampton, Boat - Gosport
    Posts
    8,874

    Default Re: Bleeding the fuel system-I dont believe it!

    How practicable would it be to move the lift pump so it's below the fuel tanks and before the primary filter? That way, it's self priming as long as there's fuel in the tanks and a tiny leak at the filter will put a bit of fuel in the bilge, rather than drawing air into the system, stopping the engine just when you'd really prefer it kept going.
    Steve
    Never believe anything until it has been officially denied.

  5. #5
    Join Date
    Oct 2012
    Location
    Southminster, essex
    Posts
    8,017

    Default Re: Bleeding the fuel system-I dont believe it!

    Put a bulb primer pump in the system. Do not have to bother with the engine lift pump . It will push fuel quite a way through the filters & draw fuel from the tank Ok
    It is all down to the fact that my wife does not understand me !!

  6. #6
    Join Date
    Jan 2011
    Location
    Shropshire/Empuriabrava
    Posts
    2,421

    Default Re: Bleeding the fuel system-I dont believe it!

    Quote Originally Posted by Daydream believer View Post
    Put a bulb primer pump in the system. Do not have to bother with the engine lift pump . It will push fuel quite a way through the filters & draw fuel from the tank Ok
    +1

  7. #7
    Join Date
    Mar 2017
    Location
    Basingstoke
    Posts
    122

    Default Re: Bleeding the fuel system-I dont believe it!

    Quote Originally Posted by Daydream believer View Post
    Put a bulb primer pump in the system. Do not have to bother with the engine lift pump . It will push fuel quite a way through the filters & draw fuel from the tank Ok
    This is what I did, has worked a treat for years. Primes in seconds.
    Youtube - Lee Shores, Lazy Jacks and Lunches
    https://youtu.be/qrkJP42i89c

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Latest YBW News

Find Boats For Sale

to
to