MF-135: bleeding the fuel system

[flusher]

I'm getting ready to change all the fluids in the 1966 MF-135 diesel that I'm fixing up.

Changing the fuel filters requires bleeding the air from the fuel lines.
That's an easy job on my 2005 Kubota B7510HST--just crank the starter.

Question: is bleeding the lines a slam dunk or a big headache on the MF-135?
Any advice and/or horror stories?

 

[JJ. in B.C.]

You shouldn't have any problem at all if you follow the correct sequence, do you have the operators manual ??

 

[flusher]

You shouldn't have any problem at all if you follow the correct sequence, do you have the operators manual ??

Yep, got the ops, service and parts manuals.

The fuel filters and the high pressure fuel pump (the injection pump) are on the left side of the engine while the low pressure fuel pump (the primary pump) is on the right side. You have to loosen air-vent plugs on the filters and on the injection pump one at a time while operating the primary fuel pump with the manual lever on that pump.

Question: do you have to close the air-vent plugs while operating the manual lever to make fuel squirt out of the vents? If so, that makes the procedure a two-person job (or single-person job if you have arms like an orangutan). Or can you lever the pump until fuel squirts and then walk around to the left side of the tractor and close the air-vent plugs?

Just trying to gauge what kind of problems I might run into if I do this job by myself.

 

[Farmwithjunk]

Yep, got the ops, service and parts manuals.

The fuel filters and the high pressure fuel pump (the injection pump) are on the left side of the engine while the low pressure fuel pump (the primary pump) is on the right side. You have to loosen air-vent plugs on the filters and on the injection pump one at a time while operating the primary fuel pump with the manual lever on that pump.

Question: do you have to close the air-vent plugs while operating the manual lever to make fuel squirt out of the vents? If so, that makes the procedure a two-person job (or single-person job if you have arms like an orangutan). Or can you lever the pump until fuel squirts and then walk around to the left side of the tractor and close the air-vent plugs?

Just trying to gauge what kind of problems I might run into if I do this job by myself.

I've gone through that filter change/bleeding air scenario about 30 times over the years on my 150. It's relatively easy, but there can be times where it doesn't go quite "by the book".

Step 1. Shut off fuel petcock on bottom of fuel tank.
Step 2. Drain filters.
Step 3. Install new filters, leaving SLIGHTLY loose.
Step 4. Open fuel petcock. As fuel begins to leak around filter, tighten completely. (May need "persuasion" with lift pump to get fuel flow to filters)
Step 5. Open bleed screw on filter and bleed all the air bubbles using lift pump to force fuel to filters. When satisfied filters are bled, close bleed screw.
Step 6. Open (I REMOVE) LOWER CHAMBER bleed screw on injector pump. Work lift pump until good flow of fuel is running from that bleed point. Close and tighten that screw.
Step 7. Do same as step 6 with UPPER CHAMBER bleed screw.
Step 8. Crack open rear-most injector line fitting nearest to cylinder head.
start cranking over starter. Fuel should seep from that loosened fitting. At that point, you're close. Engine should fire. As soon as it does, tighten fitting.

At any point where proccess starts to "break down", go back and repeat. Any amount of air in the system will cause an "air lock" of sorts.

That's what always works for me. Your results may vary.

 

[flusher]

Thanks for the details. Hope I can get the job done on the first bounce.

 

[7mmrum]

A few months ago I helped my father changed the fuel filter on his MF135 diesel, orchard model. I think it was out of commission for 2 weeks until we finally pull started it with another tractor to get it started.

We followed the book to a "T" checked other reference materials, started over, and over again with the steps to get the tractor started, it was a major pain in the butt. I don't know if I would do it again. I don't mean to shy you away from changing the fuel filter, becuase it is supposed to be changed, but on this specific tractor, whew it was a struggle to get it running again.

 

[flusher]

Thanks for sharing your trevail.

That's the reason I started this thread.

Plumbing has always been a headache for me whether it's water plumbing in the house or fuel lines on a tractor. I always run into problems and the job takes forever to finish.

 

[ozzie tractor]

the 135's aren't so bad to bleed,
1/.change filters, and open bleeders on filters,
2/.turn fuel on and start priming (yes 2 people will be MUCH easier)
3/.keep pumping until a good stream of fuel comes out the bleeder. then pump for a bit more to make shure there is no air still coming through.
4/. tighten filter bleeders and open lower one on injector pump. more pumping.
5/ now do the same for the top bleeder on the pump.
6/. now crack all the injector lined half a turn. open the throttle fully.
7/. crank the engine over until all the injector lines have fuel spraying out from around the nut.
8/. tighten injector nuts and follow normal starting procedure, but still use some throttle until the engine starts and picks up revs, then shut the throttle back to about 1/2. if it still wont start, recheck all bleeders for air, then try tightening the injector nuts while the engine is being cranked.
you really need to use a bit of throttle to give the pump enough cpacity to push any remaining air through the injector. also have a set of jumper leads handy, because now is when you will find out how good the battery is. never crank the starter for more than about 10 seconds without letting it cool either.
happy huntinng

 

[flusher]

ozzie tractor: thanks for the helpful tips.

 

[Farmwithjunk]

the 135's aren't so bad to bleed,
1/.change filters, and open bleeders on filters,
2/.turn fuel on and start priming (yes 2 people will be MUCH easier)
3/.keep pumping until a good stream of fuel comes out the bleeder. then pump for a bit more to make shure there is no air still coming through.
4/. tighten filter bleeders and open lower one on injector pump. more pumping.
5/ now do the same for the top bleeder on the pump.
6/. now crack all the injector lined half a turn. open the throttle fully.
7/. crank the engine over until all the injector lines have fuel spraying out from around the nut.
8/. tighten injector nuts and follow normal starting procedure, but still use some throttle until the engine starts and picks up revs, then shut the throttle back to about 1/2. if it still wont start, recheck all bleeders for air, then try tightening the injector nuts while the engine is being cranked.
you really need to use a bit of throttle to give the pump enough cpacity to push any remaining air through the injector. also have a set of jumper leads handy, because now is when you will find out how good the battery is. never crank the starter for more than about 10 seconds without letting it cool either.
happy huntinng

Reason why I suggested cracking open rearmost injector only? The rest are a BEAR to get at. I've always been able to bleed from one injector. BIG, old fingers don't get into tight spaces anymore.

 

[ozzie tractor]

Reason why I suggested cracking open rearmost injector only? The rest are a BEAR to get at. I've always been able to bleed from one injector. BIG, old fingers don't get into tight spaces anymore.

cant disagree with that,
hey here's an idea, lets put the fuel tank on top of the engine so you cant reach anything.
it is doable, but not easy. the spanner never really sits properly on the nut but. so rounding them off is a possibility. most of the bleeding i do is from engine rebuilds or after fuel system repairs (darn injector pump top seals again!) so there is usually a lot of air to get out. in this situation if there is not fuel at atleast 2 injectors they generally wont fire up. if 1 works for you who am i to argue, you probably have more skin left on your knukles than me too......

 

[Farmwithjunk]

cant disagree with that,
hey here's an idea, lets put the fuel tank on top of the engine so you cant reach anything.
it is doable, but not easy. the spanner never really sits properly on the nut but. so rounding them off is a possibility. most of the bleeding i do is from engine rebuilds or after fuel system repairs (darn injector pump top seals again!) so there is usually a lot of air to get out. in this situation if there is not fuel at atleast 2 injectors they generally wont fire up. if 1 works for you who am i to argue, you probably have more skin left on your knukles than me too......

Bleeding a fuel system is one of those jobs where you do JUST ENOUGH to get results and not one step further. I've always had good luck with bleeding one injector on my 150 (3 cylinder) But when I bled the system on a 6 cyl. Deere I once owned, it required bleeding at 3 or 4 points to get it to fire.

Also to consider. I never have had the injector pump apart on that Perkins 3-cylinder in the Massey. Maybe if I was dealing with a dry injector pump, I'd need to bleed at all 3 injectors. In that event, I don't see how a human hand is supposed to reach those 2 front injectors.

 

[jimmysisson]

I think I changed fuel filters on my 135 diesel three times. Never had to bleed or crack an injector, just leave the filter housing loose and pump the hand lever. Guess I was lucky - just a little spilt fuel and a minute of rough running and I was in the clear. An advantage of the top tank is fuel wants to get to the primary pump, disadvantages are it's tough if it doesn't. Give it a try - the instructions of other posters should be all you need.
Jim
Jim

 

[flusher]

I think I changed fuel filters on my 135 diesel three times. Never had to bleed or crack an injector, just leave the filter housing loose and pump the hand lever. Guess I was lucky - just a little spilt fuel and a minute of rough running and I was in the clear. An advantage of the top tank is fuel wants to get to the primary pump, disadvantages are it's tough if it doesn't. Give it a try - the instructions of other posters should be all you need.
Jim
Jim

Thanks for the info. Hope I'm just as lucky.

Could you see how much crud had collected on those fuel filters that you replaced?

 

[Farmwithjunk]

Thanks for the info. Hope I'm just as lucky.

Could you see how much crud had collected on those fuel filters that you replaced?

I've changed filters on my 150 at least once a year. A few busy years got 2 changes. So 40 or 45 changes. Maybe 10 or 12 went like a charm. i.e. bleed the filters and start up, let run, do nothing! Some days the blind squirrel finds an acorn.

It's not out of the question to see SOME water, VERY little real "dirt", but even that's better off seen in the filter than in an injector. Ideally, you want to replace a clean filter at schedualled intervals. Real world? There's some dirt going to make it all the way to your fuel filter. That's why it's there.

See a LOT of dirt at the fuel filter, a serious tank cleaning (at least) is in order more'n likely.

A little bit of dirt each year X many year old tractor = dirty fuel tank 9 times in 10. (Removed and flushed fuel tank on my 150 @ 25 year mark. Wasn't horrible, but I was amazed at how much dirt had accumulated. )

 

[flusher]

I've changed filters on my 150 at least once a year. A few busy years got 2 changes. So 40 or 45 changes. Maybe 10 or 12 went like a charm. i.e. bleed the filters and start up, let run, do nothing! Some days the blind squirrel finds an acorn.

It's not out of the question to see SOME water, VERY little real "dirt", but even that's better off seen in the filter than in an injector. Ideally, you want to replace a clean filter at schedualled intervals. Real world? There's some dirt going to make it all the way to your fuel filter. That's why it's there.

See a LOT of dirt at the fuel filter, a serious tank cleaning (at least) is in order more'n likely.

A little bit of dirt each year X many year old tractor = dirty fuel tank 9 times in 10. (Removed and flushed fuel tank on my 150 @ 25 year mark. Wasn't horrible, but I was amazed at how much dirt had accumulated. )

I'm thinking that I'll be cleaning the fuel tank also. I assume you flush it with diesel. Any special tricks to that chore?

 

[Farmwithjunk]

I'm thinking that I'll be cleaning the fuel tank also. I assume you flush it with diesel. Any special tricks to that chore?

A lot depends on how dirty, what sort of "dirt", how much rust (loose particals or surface rust on tank) The tank off of my 150 was all loose. Nothing had bonded with the tank itself. Hot soapy water and a hose got it spotless. Rust or dirt that's attached itself needs more work. Last really bad one I did went to work with me. I chucked it into a paint shaker we have to do 5-gallon cans. Then I stuffed 16' of 1/4" chain, all but the 2 hook ends, in through the filler opening. 1/2 hour, then invert for another 1/2 hour. You do the best you can with what you have to work with. Before getting too carried away, most of the popular older tractors are easy to get aftermarket replacement tanks.

Some radiator shops can hot tank a gas tank for you. They're clean after that.

Be careful to keep things clean when fueling a tractor, start with a clean tank, and keep clean filterS, and you eliminate a great many FUTURE problems.

Clean fuel, clean oil, and clean air, clean coolant .

 

[wombat50]

I realize this is an old thread but it really bailed me out. I have a 69 Massey 135, 3 cylinder Perkins diesel.
I am a beginner when working on tractors. I was not replacing filters. I had let the fuel tank run dry.
Thought I'd supply some pics because the ones in the manual were not clear to me especially
loosening a pressure line on the injection pump. As one poster mentioned I only had to do the one that ran to the rear cylinder.
If I had to do the others it would have been difficult to get a wrench on.
I hope the pics are not incorrect or misleading. Thanks for this thread!

 

[ceeceebee]

Well, just done the job, MF135 classic, 6 speed, 1966 shell fenders...wonderful runner, no smoke, starts well...I ran out of fuel and took the time to replace the filters.... job done solo, charge up the battery completely before anything else, you will need it fully charged, ...after fitting the new filters, using new seals moistened with fuel, fitted the two filters and tightened up the screws after spinning on the fittings, not the nut on top for a good central seal...if you look on the filter housings and you will see the arrows pointing the fuel flow direction, slacken off the fist inflow pipe union nut a few turns, not right off, pump the fuel through to the first filter and you will see fuel (about 25 pumps), tighten up the union, do the same with the outflow union (only a couple of pumps) tighten up, same again for the second filter, DO NOT SLACKEN THE RETURN FROM PUMP UNION... go to the lower bleed screw on the pump, use a ring spanner, slacken and pump until the fuel comes through without bubbles, second upper bleed, same again, YOU WILL GET BUBBLES, keep going until no more bubbles, pump again, check the return pipe union of the second filter for no bubbles. Right, now spin the engine over a good few times, if the engine doesn't catch, a short burst of Easystart and it will cough (the engine turns are needed to lubricate the engine anyway), spin over again and spray for 3 - 4 seconds and it will start, it will clear the air in the pipes and run fine.... if it runs rough, you will need to keep it running and loosen off the unions on the injector pipes sequentially whilst running to clear any air (I had to do this with a JD model 303 with a Standard 23c engine, a pig to start even when warm)... well this worked for me, first time and took about an hour all told.. Easystart I think it's ethylene, for you Yanks !!... Cheers from sunny SW France...

 

[Yeti49]

This post saved the day for our old community tractor following a fuel blockage. Many thanks.