Massey Ferguson MF 40 Perkins 3

[SpunkyAcres]

Hello all, hoping for some direction. My MF 40 up and quit running the other day while I was operating it. Found some, though not a lot of water in the glass fuel bowl the fuel filter seals to. Took it all apart, cleaned it all, replaced the filter and went about priming the fuel system. Pumping the manual fuel lift priming pump worked for awhile and then I stopped feeling pressure, like it wasn’t refilling between pumps. I thought maybe a faulty bleeder pump. Ordered a new one, received it, installed it and same thing. Pumped until it felt like it stopped refilling between pumps just like the original one I replaced. Here’s the odd factor. After it quits pumping, if I loosen the inflow line coming from the fuel tank, it will spew fuel out like it is under pressure. After the pressure relief, and retightening the line, I pump it again and have the same result. It quits pumping and feels like it isn’t refilling. Same thing every time. Loosen the inflow, release pressure, retighten and it pumps for awhile again. Acts like something is plugged down line yet I have fuel gravity flowing to the bottom bleed screw of the injector pump. Thought maybe the cam was in the wrong spot not allowing the pump to work, turned over the motor and tried, no different. Very baffling as I am bleeding it the same as I always have. Please!, any ideas?
Thanks!!

 

[mg2361]

Welcome to HEF Spunky!

I know nothing about Massey's, but I assume it has Perkins in it? How about posting a picture of your lift pump so those in the know will be able to better help.

Also, are you trying to bleed the fuel with a bleeder open? Or are you just pumping the lever with no bleeder open? If you do not have a bleeder open, most lift pump levers will go "limp" when they encounter head pressure.

 

[Delmer]

The going limp is normal operation. The priming lever operates the same diaphragm as the camshaft operates (which is why if it's on the cam lobe it won't operate like you mentioned). That diaphragm wouldn't last an hour if it was pumping the full stroke of every lift of the cam. What you feel when you pump is the return spring that you're compressing, that spring applies pressure to the fuel when you release the lever, if the fuel doesn't flow because it's built up pressure, then that spring doesn't return and there is no resistance on the next stroke. Release fuel from the bleeder and you get a couple strokes of pressure and then it goes limp again. All normal.

The fun part is while compressing the spring you're also sucking fuel into the pump diaphragm, so if you remove the inlet and place a finger over it, then try to pull fuel under vacuum, it gets harder to pump. So if you ever notice that, then your fuel supply is blocked before the pump.

To get your perkins running, bleed air from both bleeders, and then if it doesn't start right away, loosen one or two injector lines at the injector, and crank until there are no more air bubbles, just spurts of fuel, tighten those lines and it should start right away.

 

[heymccall]

Does this page help?

Massey Ferguson Tractor Fuel Starvation

Identify and repair fuel starvation problems experienced with your Massey Ferguson Tractor

www.agriline.co.za

 

[SpunkyAcres]

Thank you mg 2361, Delmer and heymccall for responding.
I responded back via email not realizing I had to do so through the forum.

Thank you mg 2361 for the response. Yes, a Perkins. I will work on photos. I have had bleeders opened, lines loosened etc. to no avail. I now have it pulled out of the orchard and close to my shop so it’ll be easier to work on. I will start from the beginning in the bleeding process and see where it goes. Limp is a good description of the symptom.

Just saw the response from Delmer and hey mccall as well, thank you. Gives me some direction for sure. The illustration hey mccall posted made me think of something else. There is a reservoir on the front end of the injector pump with a rubber type compression plug that seals the fill port. Can y’all tell me the function of this and what goes in it? Thanks again.

Those were my emails. I knew something was amiss when I received no response back.
The diagram mccall sent is very close to what I have on my MF. The diagram shows a primary and a secondary filter. My filter assembly resembles the secondary filter with a glass bowl on the bottom of it. Where the diagram shows “bleed points”, mine is a nut that screws into a “stem tube” that comes up thru the bottom of the assembly.
The top housing has 4 ports on it, 1 with a plug in it. After puttering more with trying to get things to bleed I’ve come to the conclusion something is possibly plugged up in the top housing not allowing fuel to continue down line to the injector pump. When I loosen the incoming fuel line to the top housing, fuel will bleed out of the fitting with the bleed pump. I then loosen the line to the injector pump exiting the top housing and am still experiencing back pressure in the bleed pump as before instead of fuel coming out of that fitting. That’s what has brought me to the conclusion something is plugged in the top housing.
I have been attempting to remove the top housing to check and clean it. The 3 fittings have screwed out fine but I have been unable to pull the lines out of the housing. I have to believe the steel fuel lines are flare fittings. I can wiggle them back and forth so they are loose, they just won’t come out and I don’t want to damage them and create more work for myself.
Quite frustrating as I’m in my 60’s, grew up on a apple farm and have had a wrench in my hand since I was about 8 fixing my Stingray bicycle.
Thanks for past and future responses. Now that I know I need to respond back on the forum I’ve learned something new today. It‘s a sad day when you don’t learn something new.
I likely won’t be able to respond for the next few weeks as the wife and I are headed for England, Scotland and Ireland on Monday.
Again, Thanks!!

 

[Delmer]

I would need to see a picture of the reservoir on front of the injection pump, that doesn't sound familiar.

You're on the right track, don't try cranking until you get fuel out of the bleeders on the injection pump. Obviously that won't happen until it gets through the filter housing. You could leave the pipes in place and blow back with compressed air from the other end. I can't say why they won't come out?

Double check the filter. I believe fuel goes in the bottom and up though the filter element and out the top. Compare to the old one, double check the number, location of seals. It seems like some filters were made with openings that could be blocked somehow, I can't remember exactly, but I'd remove the filter and use air to confirm that the ports are open and flowing, then check the filter and put it back to see where the fuel goes, and doesn't go.

 

[Tones]

Those fuel filters can be a pain especially with the rubber seals in the filter housing . Sometimes they haven't been replaced, become hard and leak air or the filter doesn't seat properly. At times I have found more than1 seal in there.