Help with a L4630 WSM issue (and tractor stalling issue)

[Derf]

My L4630 GST is a used one I bought from my neighbor a couple of years ago. It has been very reliable, but I decided to replace the fuel filter based on the hours I had used it. I used this image from the workshop manual for bleeding after I finished, but the fuel cock (see inset image) on mine can swivel from "A" to 180 degrees (90 degrees past the vertical line in the image). The inset image seems to indicate that the vertical line means something, but there's no "B" location for open, like there is on the air vent cock. Also the arrow for the fuel cock is pointing from the vertical line toward the "A", despite the text indicating that the fuel cock needs to be "open" and the description says "A" is "closed".

So, can anyone explain what position should be used for the fuel cock while bleeding, and what position do I leave it in when I'm done bleeding?

 

[North Idaho Wolfman]

Sorry but your getting a little confused, the WSM can do that.

The Fuel Cock on the filter housing flag should be sideways (A position) to shut off fuel flow when you change the filter, then opened to the #1 position when it's in run mode.


The Air vent on the side of the injection pump will turn mutiple times, just turn it counter clockwise ( B direction) like one turn to bleed the air out of the line and pump, then turn it clockwise (A direction) to close the valve.

 

[Derf]

Sorry but your getting a little confused, the WSM can do that.

The Fuel Cock on the filter housing flag should be sideways (A position) to shut off fuel flow when you change the filter, then opened to the #1 position when it's in run mode.
View attachment 176463

That's what I was thinking, so I seem to be doing the right thing. What happens when I turn the fuel cock the opposite way from "A"?

Also, if I try to start and run the tractor with it in "A" position, shouldn't it either not start or not keep running, since it is cutting off fuel going into the filter?

The Air vent on the side of the injection pump will turn mutiple times, just turn it counter clockwise ( B direction) like one turn to bleed the air out of the line and pump, then turn it clockwise (A direction) to close the valve.

View attachment 176464

So I've done this a few times now, leaving the engine running 30 seconds up to over a minute, and it still stalls after just a couple feet of forward movement (reverse seems to go a little farther). I would guess that either means it's not a bleeding problem or the valves aren't doing what they are supposed to. I saw a post from someone that they had installed their fuel filter upside down. Maybe I ought to check that.

 

[North Idaho Wolfman]

That's what I was thinking, so I seem to be doing the right thing. What happens when I turn the fuel cock the opposite way from "A"?

Also, if I try to start and run the tractor with it in "A" position, shouldn't it either not start or not keep running, since it is cutting off fuel going into the filter?


So I've done this a few times now, leaving the engine running 30 seconds up to over a minute, and it still stalls after just a couple feet of forward movement (reverse seems to go a little farther). I would guess that either means it's not a bleeding problem or the valves aren't doing what they are supposed to. I saw a post from someone that they had installed their fuel filter upside down. Maybe I ought to check that.

Take the output hose off of the filter housing and see if there is good continuous flow coming out of it.
These style of filter housings have been know to clog up the intake side of the filter housing.



If you have good continuous flow out of the housing, move up the chain.
Go to the output of the lift pump.


Remove the line at the injection pump input and put it into a container.
Start the tractor ( it will run for quite a while on the fuel in the injection pump housing) and look for pulses of fuel out of that line.



No pulses of fuel bad lift pump, pulses of fuel good pump.

If that is good then your chances of it being a fuel supply issue are low.

 

[Russell King]

@North Idaho Wolfman
Is there any possibility that the air vent being open (even if you think it is closed) could cause the issue?

I seem to recall someone having a running issue and finally figured out that the air bleed was open but may be recalling it incorrectly.

 

[North Idaho Wolfman]

@North Idaho Wolfman
Is there any possibility that the air vent being open (even if you think it is closed) could cause the issue?

I seem to recall someone having a running issue and finally figured out that the air bleed was open but may be recalling it incorrectly.

It can, but usually you'll only notice it when the the lift pump is bad, as it normally will move more diesel than the tractor uses.
Easy to test, just pull off the vent line, if diesel comes out off the shut off when it closed, it's bad.

 

[whitetiger]

Also, see if the hose barb fittings are tight in the filter head. If they become loose, you will suck air around them.