1968 MF 135 Diesel died and won’t restart

[Whistlin10Speed]

Today I went to bush hog with my 68 MF 135 with the Perkins diesel.

It fired right up as always and off I went, I mowed about 3 passes and it just died out of nowhere and would not restart. The fuel filter was in pretty bad shape so I replaced it and then bled the fuel system, starting with the filter, the the lower injection pump bleeder, then upper injection pump bleeder. I bled them all until there was no air or bubbles and it had a steady stream of fuel.

It still would not start after this. I did not crack the injectors and bleed them. Does anyone have any ideas? The injection pump is definitely getting fuel so I know the mechanical pump is working. The fuel is clean, brand new filter and freshly cleaned sediment bowl.

I am wondering if I have an injection pump issue but am not sure how to verify that.

 

[REB126]

Crack the injectors. I had the same issue and tried it with and without cracking the injectors. It only worked when I cracked them.

 

[Jim.ME]

Crack the lines nuts loose to bleed the high-pressure lines at the injectors. Fuel set about 3/4 throttle, the fuel stop in the run positions and crank the engine (or tow it, if you have that option available).

 

[Whistlin10Speed]

Crack the lines nuts loose to bleed the high-pressure lines at the injectors. Fuel set about 3/4 throttle, the fuel stop in the run positions and crank the engine (or tow it, if you have that option available).

Do I need a special wrench? I have seen some people saying a standard 15mm or 5/8” wrench won’t fit.

 

[wh]

Neighbor had a mf 150. Same engine. Ran it out of fuel. Would not start. Finally called me. We pulled it in shop and charged battery. Bled lines at filter then pump. Loosened all lines at injectors. Took a minute. That was the hardest engine to bleed I have ever fooled with.

 

[Whistlin10Speed]

Neighbor had a mf 150. Same engine. Ran it out of fuel. Would not start. Finally called me. We pulled it in shop and charged battery. Bled lines at filter then pump. Loosened all lines at injectors. Took a minute. That was the hardest engine to bleed I have ever

Someone told me that when I first got it. Definitely learning the hard way. Luckily I didn’t run it out of fuel.

 

[Whistlin10Speed]

Crack the injectors. I had the same issue and tried it with and without cracking the injectors. It only worked when I cracked them.

Did you use a standard 5/8 wrench or did you have to use a flare nut wrench?

 

[Jim.ME]

It is a standard wrench, I forget what the size is off hand, but you will find it is a common SAE or metric size.

 

[Whistlin10Speed]

It is a standard wrench, I forget what the size is off hand, but you will find it is a common SAE or metric size.

I believe it is 5/8 or 15mm from reading online. Just saw some people saying it was difficult, I have never messed injectors before so I didn’t want to make it any harder.

 

[Jim.ME]

Someone told me that when I first got it. Definitely learning the hard way. Luckily I didn’t run it out of fuel.

If the fuel filter plugged you ran the injection pump out of fuel, even though it had fuel in the tank.

 

[Jim.ME]

I believe it is 5/8 or 15mm from reading online. Just saw some people saying it was difficult, I have never messed injectors before so I didn’t want to make it any harder.

They can be difficult to get at, just a day in the life of a mechanic.

 

[Whistlin10Speed]

If the fuel filter plugged you ran the injection pump out of fuel, even though it had fuel in the tank.

I am assuming that is what happened. That’s the only thing I can think it would be. Being a diesel I would think it has to be fuel related.

 

[wh]

Had a rubber fuel line to crack once and allow air to enter lines. Tractor shut off like it had run out of fuel.

 

[Whistlin10Speed]

Had a rubber fuel line to crack once and allow air to enter lines. Tractor shut off like it had run out of fuel.

I believe they are all steel hard lines on the MF 135 with the Perkins. There may be a rubber return hose but I think that is the only one.

 

[phil25]

you will most likely find that getting to all the injectors is a "pain in the rear" so, crack the ones you you can reach, one or two at least, and then crank it over until fuel is flowing, tighten the lines and
try to start. it will take a bit longer to actually run like it should, but it will begin to cough and self bleed the remaining injectors.

 

[Whistlin10Speed]

One thing I failed to mention, right before this I checked the air filter (in horrible shape) and I figured it’d be fine for a quick mow while I wait on one to come in.

Is there any possibility the air filter/ air intake has anything to do with this? The tractor showed zero signs of issue before I took the filter out and put it back.

 

[Whistlin10Speed]

Thanks everybody. I bled the injectors and it fired right up and ran great I mowed 7 acres with it today no issue. I appreciate the help!