Chamberlain CJD791 - Fuel line problems

Hello ,
My Chamberlain CJD791 has a blockage in the fuel line somewhere. Just before she stopped I heard a few odd sounds, and she seemed to skip a beat.
My fuel systems begins with the glass bowl, then lift pump, then filter with glass trap underneath (this currently has no fuel in it after changing the filter), then the line goes to the other side of the tractor to another filter, and then the fuel injector.
I have changed both the filters and cleaned out the glass bowl. When I manually pump fuel with the lift pump I get on a few drops of fuel coming through to the glass bowl. It took about 15 minutes to just fill the glass bowl. I can't get any fuel now to go into the next part (filter with glass trap underneath).
Does anyone have any suggestions?
Regards
Scott

I had a similar problem with one of my tractors, turned out the blockage was in the suction pipe in the fuel tank. I could only pump a few drops at a time with the lift pump till I cleared the obstruction .

Get a Good Torch & look in the tank & ensure there's nothing Floating around in there restricting the outlet.
Undo each fuel line & blow compressed air through them to ensure their not Blocked/restricted.
You may have to give the Key a quick flick to ensure the Lift Pump follower is not sitting on the camshaft, as that can limit how much you can pump by hand.

I am guessing your fuel supply starts with a pipe coming out the bottom of the fuel tank, in which case there will be a blockage either inside the tank, at a strainer, elbow or any other constriction before the lift pump. Blowing air back up the line from the lift pump will get you going however there is a risk that the blockage will return - usually when you are nowhere near the workshop. Accordingly the best approach is the dismantle the fuel supply line until you have identified where the bolckage is and maybe you can make some alterations so that it doesn't recur. Having changed the filters you will have to bleed it well. Good luck

So two things already mentioned

Make sure the lift pump isnt on the cam lobe, just turn the motor a touch on the key

The other is the fuel tank as mentioned
All Chamberlain tractors I have had anything to do with I cab pull a big section to expose a hole at guess 2 inches diameter and you can make sure the tank is spotless then
Pretty sure there's not even a lip left on the bottom of the tank

Paul

I have not needed to look inside my chamberlain fuel tank, but I recall my old inter conking out, fuel starved. Fix was easy when located, the strainer inside the fuel tank had gummed or waxed up. The strainer was screwed into the bottom of the tank and the fuel line tap screwed into that. If I remember right, it washed out in hot soapy water.

Good luck, let us know how you go.

I think I d be looking at the lift pump first ......the AC pump is a very poor quality item ,and quite often the valves come loose in the die cast pot metal body ....the general idea was to replace the pump with a new one ,and in fact ,many lift pumps are sealed on american motors ,and cant be serviced......Ive also had major problems with the glass bowls on CAV filters ....without new rubber rings ,they just wont seal ,and leak air.....Tighten them a bit too much ,and the glass breaks,or the bolt strips .I had a lot of trouble with my Chamberlain (4/270) with fuel fungus ,which made slimy stuff that stopped the valves in the lift pump sealing.....long strands of black "snot"......cured with some of the marine stuff for diesel tanks in boats.

Thankyou all for your detailed replies.
I have siphoned fuel out of the tank and taken a photo. There is clearly lots of black gunk at the bottom and also on the side of the tank. Might need a clean. I think also try to clean the outlet of the tank. Can anyone help explain the process in my doing a complete clean. I have also taken a photo from underneath the tank where there are two taps.

I would undo those bolts around the tap assembly and drop the whole tap out

From memory they are a pretty big hole

I have had the taps so gummed up they are seized solid but with time and gentle persuasion they come loose as well

Paul

Having played with more that a few tractors in my time, I'd be tipping the blockage is in the bottom of the tank. They all suffer from this problem, IH MF, Case, Ford. I've had it in just about every make of tractor over the years of having a tractor and machinery business here on the south coast.

If you can get the fitting out of the tank, you will most likely find a gauze strainer blocked and just letting a trickle through. I found the best thing to clean them out was a bit of Carby Cleaner then blow them clear.

Just my 20 cents worth.