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Fuel Leaks…again

Discussion in 'Fuel System & Electrics' started by phantom, Feb 1, 2015.

  1. phantom

    phantom Member

    Messages:
    363
    Location:
    Rural NSW
    Again I am fighting fuel leaks and am getting quite paranoid over them.

    Todays patient is my 75 Bay, all standard with 1800 and twin carbies, but with an electric fuel pump over the factory fit. A couple of months ago I had fuel lines changed after a big fuel leak….all were done except for the small one from the tank to the pump. All has been good since then.

    This morning we were out of town with the car and I find a fuel smell when I go out to the car, to find the drivers side carby is leaking fuel into the engine bay and out the bottom.

    The car was on a slight hill and I remember reading of some form of issue that might have been something about having the tank higher than the carbies, or something….can lead to leaks. Tank would have been close to full (maybe 5 litres out of it), and the hill was only slight.

    I've not had this before, I've had this car over 3 yrs without this issue, my Kombi ute (type 1 engine) parks on a slight rise all the time and does not have this problem, neither have our beetles.

    I moved the car off the hill and the leaking stopped. Tried to dry the engine and air it out for around 20 mins, had to leave and all was OK for the trip back. It isn't leaking now it is on the flat at home.

    Can someone please enlighten me on this one, along the lines of:
    - is this a known issue
    - what causes it
    - is it a quick thing (i.e. known leaking spot) or does it seep out of something
    - is there an easy fix, or is it a case of not parking on hills (not easy?)

    Any and all info appreciated, thanks!
     
  2. Barry

    Barry Well-Known Member

    Messages:
    3,599
    Location:
    Abbotsford NSW
    can i ask where it is leaking from?

    If it was a stuck needle and seat it would leak into the engine

    if it is leaking into the engine bay it has to leak from outside the carb - hose etc
     
  3. Mellow Yellow 74

    Mellow Yellow 74 Active Member

    Messages:
    845
    Location:
    Sydney
  4. Kai

    Kai Well-Known Member

    Messages:
    4,716
    Location:
    Sydney, NSW
  5. phantom

    phantom Member

    Messages:
    363
    Location:
    Rural NSW
    Thanks all, I'll have a look at those links.
    The fuel is not leaking from the hose, it is leaking 'internal' to the carby, i.e. it is dripping at the back of the carby, as in when you look at it from the engine hatch. it is drooping outside the carby into the engine bay. The new hose (at the front of the carby - front of car) is good, new hose clamp, etc.
    It only did it when parked on a hill (nose up), and stopped when I moved the car to a more level area, with no other changes.
    I didn't think fuel would flow if the pump was not running, maybe those links will help.
    Thanks all.
     
  6. Kai

    Kai Well-Known Member

    Messages:
    4,716
    Location:
    Sydney, NSW
    Sounds like the fuel is overflowing from the fuel bowl and out the throttle shafts check your float and needle and seat
     
  7. cbus

    cbus Well-Known Member

    Messages:
    11,709
    Location:
    sunshine coast
    My pick would be needle seat. seems like classic' on angle' issue . float is allowing fuel in and its possible for the fuel to go down throat of carb and past piston into sump in some situations so before starting always have it on the flat and check oil level and for signs of fuel in oil if you get the fuel smell or sus for any other reason.
    Have heard that some new needle seats can be sus quality so give the old one a clean and check first.
    check that float is not holed or saturated.
    other than parking on the flat you can add a fuel shut off valve and tachometric relay which isn't a bad idea when using electric pumps
     
    Miss Rosie likes this.
  8. Grantus

    Grantus Well-Known Member

    Messages:
    15,664
    Location:
    Southern ACT
    Bruce, whos's doing the servicing on the bus these days?

    Yourself in house, or a paid mechanic? :rolleyes:
     
    Last edited: Feb 3, 2015
  9. phantom

    phantom Member

    Messages:
    363
    Location:
    Rural NSW
    Thanks all, I have a mechanic coming today to have a look and hopefully find the issue, I'll pass on these comments so that he can hopefully locate it quickly.

    For Grantus - I noted that smiley face :) all paid mech's for these cars.
     
  10. Kai

    Kai Well-Known Member

    Messages:
    4,716
    Location:
    Sydney, NSW
    I can echo cbus' recommendations re: checking the oil before start up. More than likely if you have fuel spilling out of the bowl it would have seeped into your sump as well. Better to be safe than sorry when oil costs like $30.
     
  11. 1500king

    1500king Well-Known Member

    Messages:
    1,544
    Location:
    Adelaide, SA
    This is fuel siphoning folks.

    Yes, your tank is higher than the carbs,

    The original pump had an anti-siphon valve in the top of it to stop any siphoning with engine off.

    You need a fuel lock-off valve between the electric pump and tank, below;

    http://www.ebay.com.au/itm/LPG-Conv...ol-Fuel-Lock-Off-Solenoid-Valve-/330972886035.

    You will need 2x 3/16 barbed fittings with 1/8 NPT thread(check your tank outlet, x1 might need to be larger) . If you have a pump with 1/8 NPT threads, you can screw the valve to the pump with a 1/8 NPT male fitting.

    Make sure you use pipe sealer to seal the threads (Loctite 577/567) otherwise fuel will leak past the threads. Do NOT use pipe tape.

    You also need a Tachometric relay to run the pump and prime the carbs/lock off valve ONLY when you are starting/running the motor, below;

    http://www.ebay.com.au/itm/LPG-Safe...=AU_Car_Parts_Accessories&hash=item35d4321b04

    Make sure you use a good quality fuel pump (such as a Pierburg roller cell pump- also quiet, don't rattle) which are accurately internally regulated.

    Agree re; checking the oil, chances are that your engine has filled with fuel and diluted the oil. Will need to be changed.
     
    Shanew88, Grantus and john doherty like this.
  12. john doherty

    john doherty Well-Known Member

    Messages:
    798
    Location:
    adelaide
    Mr 1500 King,

    Delighted to once again, orb input from your learned self. I have always learnt so much from your considered input on this forum for which I extend my heartfelt appreciation and gratitude.
    Thank you for taking the time.
    Warm regards
    JD
     
  13. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,809
    Location:
    Penna, Hobart
    https://www.injectorsonline.com.au/...r-surge-tanks/pierburg-3-5-psi-lift-pump.html

    This is the link for the pumps at injectors on line as at today. $105 +GST + shipping. They also have 8mm barbed connections so you may have to have some adapters to change from the 7mm from the fuel tank (or filter) and the 5 mm for the carb themselves. After the fire on the weekend taking some of the advice in this thread may help to save a few more vehicles.

    The cost of the parts would be just over $200 + another $50 for decent fuel hose and that in my opinion (even if you add the cost of install) has got to be worth it compared with the heart ache of your vehicle going up in smoke.

    Adrian
     
  14. phantom

    phantom Member

    Messages:
    363
    Location:
    Rural NSW
    Thanks everyone. I have not checked the oil yet and will have to do this on the weekend. The leak looked to be a couple of loose screws at the back of the carby. The mechanic tightened them and I parked the car on an incline for the afternoon without any leaks. Fingers crossed it was as simple as this.
     
  15. saabman

    saabman Well-Known Member

    Messages:
    4,796
    Location:
    Goulburn
    A couple of years ago a mate parked his kombi on my slopped driveway for the night just after having an electric fuel pump fitted we found in the moring a trail of oily fuel running down the driveway :eek:

    The fuel had siphoned out of the tank through the pump and carbies filled the sump.

    Required draining the oil and the muffler :eek:

    A check valve in the fuel line fixed the problem.

    In most cars fitting an electric pump is not an issue as the tank is lower than the carbies so the fuel can't free flow out. But as others have mentioned the hight of the kombi tank causes the problem.

    It's what happens when an ignorant mechanic thinks he/she knows what they are doing with a kombi - it's just like a beetle isn't it?
     
  16. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,809
    Location:
    Penna, Hobart
    Or worse -"its just like a Holden/Ford" :eek:

    Adrian
     
  17. The Powerhouse

    The Powerhouse New Member

    Messages:
    11
    Location:
    Brisbane
    I have the same feel leak problem with my 76 2 litre with twin solex carbs. It is the drivers side carb too but my Kombi is parked on level ground in my garage. First noticed smell of fuel and then the dripping, that was a couple of months ago. My engine is fitted with the very large air cleaner system the routes around the top of the engine bay. This morning I took all of this off, cleaned up the engine bay, removed the carburettor but didn't take it apart as it looked ok, seemed a bit oily around the air inlet. Cleaned everything off and put it all back together. I noticed the pipework from the big air cleaner was a bit oily on the big rubber hose where it connects to the top of the carb. All new fuel hoses where fitted last December and the carbs were stripped and put back together as part of a major service carried out. Anyway, after I completed the work this morning I started the Kombi up, went ok then I noticed the rainbow oily marks on the driveway were it was still wet from the rain, was definitely from the exhaust. The exhaust then became very smoky and the engine stopped. I haven't started it since, it turns over ok though. I looked back in to the engine bay to see fuel leak again which seemed to be coming from the air cleaner piping. When I removed it it was very wet. I'm just waiting now to see if it evaporates (if it is petrol) or how oily it really is.

    Any thoughts folks? I was hoping to use to this weekend but looks doubtful.

    Don't really want the hassle of taking it back to the shop, it is 2 1/2 hours away. I've only driven it back from the garage last December since all the engine oil seal work, carb rebuild, service and new fuel lines were fitted.

    Cheers, Ian.
     
  18. The Powerhouse

    The Powerhouse New Member

    Messages:
    11
    Location:
    Brisbane
    Update.

    Just checked air cleaner piping, oily residue mixed with fuel, not just fuel. Also dipstick is very clean, no obvious level showing but very clear oil. Its only done 200 kms since oil and filter change so something wrong here. I'm now suspecting engine full of oil and fuel mixture which would help explain oily rainbows on ground and smoky exhaust. About to drop contents of engine.
     
  19. The Powerhouse

    The Powerhouse New Member

    Messages:
    11
    Location:
    Brisbane
    Forgot to mention my air cleaner is the Donaldson type, it was dry on the passenger side carby, oily wet on the drivers side.
     
  20. saabman

    saabman Well-Known Member

    Messages:
    4,796
    Location:
    Goulburn
    Do you have an electric fuel pump fitted?

    If you do you MUST have a check valve ( I think that's the right term) fitted between the pump and the carby.

    If you don't the fuel will just drain out of the tank through the carby into your cylinders and into the sump.

    It is quiet common for non vw mechanics to fit an electric fuel pump without the check valve as most ( all) cars have the fuel tank lower than the engine so it is not required - but as the kombis tank is higher than the engine the fuel will just run out.

    I'm going to speculate a little here

    in my experience I have found the float valve mechanism in the carby to seal very well which would prevent the fuel from flowing but the correct fuel level is very close to the top of the Venturi so If the van Is on a slight angle the fuel will flow out of the carby dropping the float level and opening the valve.

    If this is still happening and the van is parked on level ground than I would consider the possibility that the float level is set to high one or both of the carbies. This I figgure would cause then engine to run rich.
     

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