Engine Fuel Leak

OhioCowboy · Mar 11, 2015

I've been turning off the fuel at the filter bowl for the last year to stop a fuel leak somewhere near the fuel injectors. No problems starting or running. Just seeps fuel out whenever I park it. drip...drip...drip... I'm getting weary of forgetting to turn the fuel on and forgetting to turn the fuel off. Forgetting to turn it back on is the real PITA. This spring I want to fix it. Possible O ring in an injector? If so, is this something that I can do or is it something I should pay the dealer to pickup/fix/return to me?
Thanks

Gordon Gould · Mar 11, 2015

Is it a Lucas CAV pump that is leaking ? And does it leak at the throttle and/or shut off shaft ?? see pic.
If so, it is a pretty straight forward $10 -$20 fix. Replace a gasket and 4 O-rings, I have some links to online help I can give you if this is your problem. I did mine last summer.

gg

Gordon Gould · Mar 11, 2015

Cowboy look at this thread - go to the end. I have two posts in it with some good instructional links on that repair.

http://www.tractorbynet.com/forums/...ford-tractor-cva-post4016020.html#post4016020

hope it helps

gg

OhioCowboy · Mar 11, 2015

Good instructions-thanks will keep in my references. Here's a picture of where my leak is on my tractor. Seeping from one of the 3 tubes by the red arrow. I crack them open to bleed air when needed in addition to the bleeder shown just above the leak. Maybe I'm wrong and those 3 are not the injectors? The injectors are at the other end of the tubing (Yellow arrows)?

Gordon Gould · Mar 11, 2015

You are right that is an injector line. When I read o-ring fix and saw you had a ford I assumed (incorrectly) that you might have the very common throttle shaft drip on Lucas CAV pumps which are on lots of fords.
Sorry to send you in the wrong direction and good luck with it.

OhioCowboy · Mar 11, 2015

After digging a little I see it is leaking from the top of the injector pump. The injectors are at the other end of the tubing (top yellow arrow)

OhioCowboy · Mar 11, 2015

Not a problem. My original question was not clear. I'm not all that familiar with diesels and their components yet. Thanks for your help.

DT86 · Mar 11, 2015

OhioCowboy said:
Not a problem. My original question was not clear. I'm not all that familiar with diesels and their components yet. Thanks for your help.

We all have to start somewhere!

The bottom yellow arrow, opposite the injectors, is pointed to the fuel delivery valves.

OhioCowboy · Mar 11, 2015

Thanks for that. In case anyone else might have the same problem, Here's a diagram that shows there are 3 o-rings on each of the "delivery valves" - part #5 is the delivery valve assembly (thanks DT86). I'll start with part # 2 o-ring then #15 if that doesn't stop the leak.

OhioCowboy · Mar 11, 2015

Maybe I won't be able to replace the o-rings. According to Messick's website the pump is not seviceable. I have to buy the whole pump for $1,100-$1,400 instead of replacing a 50 cent 0-ring. ......I don't think so....

DT86 · Mar 11, 2015

Grab a phone book or better yet search online and look for diesel injection services near you.

skyhook · Mar 12, 2015

If it were me, with the engine "cold', I would clean all around those 3 injector feed lines and also that rubber hose above it, I don't know what it is but it could be leaking from there and going down on those line fittings. Clean er up good just to verify where the leak is coming from.

OhioCowboy · Mar 12, 2015

Good point. Seems like the rubber hose connection would be the weakest link. Any idea what that rubber hose is for? Return line? What's the reason for a return line?
Thanks

ThomasH · Mar 12, 2015

OhioCowboy said:
Good point. Seems like the rubber hose connection would be the weakest link. Any idea what that rubber hose is for? Return line? What's the reason for a return line?
Thanks

It is there because the injectors you have are 'popoff' type injectors. The pump builds pressure until the valve pops open and sprays, and then the pressure decreases until the valve closes. The excess fuel that is not needed at that point is returned to the tank.

The rubber hoses are not under much pressure, so unless they are cracked, rotten, etc., they probably aren't leaking. Many tractors just have small spring type hose clamps on those fittings to hold the rubber hoses on. But in case you do need to replace them, make sure you get diesel fuel rated hoses, which are typically teflon lined. You can get it at an auto parts store.

OhioCowboy · Mar 14, 2015

Today I cleaned the area where it's leaking and noted that as soon as I turn on the fuel (without the engine running) at the sediment bowl it starts leaking around this middle plate. I have not loosened this plate, but I have cracked open the hex nuts to bleed air. Does fuel come from the sediment bowl to the pump through the rubber hose above the red arrow?

Harry in Ky · Mar 14, 2015

It's your tractor so it's your choice. If it were mine, I would clean off the I.D. plate on the pump, jot down the numbers, and call my local fuel injection pump shop. Read them the numbers, describe what/where the leak is, and see what they tell you about repairs and prices. I would NOT attempt to remove the individual components from the pump. That's just looking for trouble. I have removed and installed any number of such pumps(the whole pump), it's not that difficult. Again, your money -- your choice.

skyhook · Mar 15, 2015

OhioCowboy said:
Today I cleaned the area where it's leaking and noted that as soon as I turn on the fuel (without the engine running) at the sediment bowl it starts leaking around this middle plate. I have not loosened this plate, but I have cracked open the hex nuts to bleed air. Does fuel come from the sediment bowl to the pump through the rubber hose above the red arrow? View attachment 416546

Your guess is as good as mine....
follow the hose and that should tell you, but it does look like a return line.
If you "cracked" open those hex nuts beside the red arrow for bleeding???why?
You should crack the injection lines at the injectors, not where you did, you may have let some dirt in.
So you have confirmed that its not leaking from that hose?
I personally would use "brake clean" to clean that up, it will remove any fuel and give you a better picture,
I would also wiggle that hose to check for leaks to eliminate it from or for a possible leak.
But if your saying its leaking from that middle injector line housing, then it could be that seal you referred to.
Make sure you eliminate all other possibilities before, playing with the injection pump could be costly.

OhioCowboy · Mar 15, 2015

Will clean everything, snug up all connections and see what happens.
Thanks all for your thoughts on this.

OhioCowboy · Feb 24, 2021

Sorry to drop out after fixing the problem. I loosened up the nut that I was using for bleeding (The one that held the middle plate) then sprayed the area real good with carb cleaner. Then I tightened everything I could find. The leak stopped. My next fix was to replace o-ring "2" in the breakdown drawing, then o-rings "15".