M4000 injection pump questions

[MdStihl]

Hi there, looking for some info. This is what I have:

At least one line, possibly 2, are leaking where they thread onto the holders on top of the inj. pump. *edit* stated that wrong. I THINK it's leaking around the base of the holder that they thread onto. I will also check for cracks on the flare ends though.

I have the gaskets, holders and springs ordered according to the parts book. (ordered springs because they're cheap, in case I lose some) I also have on order the shop manual that should answer any questions. But, real world experience is priceless, so....

It looks to me like there's not enough room to get a socket onto some of the holders that are next to the intake manifold to torque them properly. To do the job right, must I pull the inj. pump, or the manifold? Or is there a special tool I'm not aware of? From replacing the fuel injectors some years back, I remember it's about impossible to get a 19mm wrench on some of the holders while tightening the 17mm flare end. I believe this may have been the root cause of some of the leakage.

Are there any pitfalls I should be aware of going in? I have a decent amount of "farm mechanic" experience, but that won't stop me from making that one expensive mistake.

My shop manual should be here in a few days, so I'm thinking it should have everything I need? But again, I'm wide open to suggestions.

I've got all the sheet metal off to make working on it as easy as possible. I've owned this tractor for nearly 15 years, so I'm pretty familiar with it. I just know the pump is a delicate instrument. I"m not planning on going further than replacing the gaskets under the holders, and checking for cracks on the flare end of the line itself.

Thanks all in advance!
Repectfully,
John King

 

[North Idaho Wolfman]

With the right thin wall sockets and knowledge you can do it in the engine, but it's delicate work and hard to perform in the tractor.

Clean the injection pump and around it completely before pulling the pump, after doing so pull the injection pump and get it on a workbench to perform the repairs!
Do one at a time and be very accurate as to the direction of internal parts, do not force anything together.

 

[Kubota Newbie]

Yeah, you're gonna be pretty disappointed in the WSM if you're wanting to do much injector pump work. Not much detail, no torque specs for the lines & etc. at least not in the copy I have. I'd wager someone cracked (loosened) the lines some time thinking they need to do that to bleed the pump and backed them off a touch. Was me I'd try making my self a "line wrench" out of an old box end and just try snugging them down a little.

 

[Benjaminearl]

It can be done without pulling the pump. Use a19 wrench. If you have to turn the holders on both sides of the leaking one to make a normal wrench fit. Loosen and be aware that when you get to end of threads a spring will want to pop it off, so hold down on it. Pull out very carefully as there is little shim and springs and washers. Keep in exact order. Change oring on holder and reassemble. Careful not to over tighten. I did all 6 on my m4500 and I'm just a backyard farm mechanic whose cheap. My local injection shop told me I should do that. Any deeper in the pump and you'd need experience to tune and adjust settings.

 

[Benjaminearl]

One holder at a time. Don't try to tear more than one and lose pieces

 

[MdStihl]

Thanks for the responses, both of you. I was afraid I'd end up pulling the pump. I'll of course make sure everything is TDC before I do that, and clean thoroughly.

and darn, was hoping that WSM would be more complete, but oh well. This ain't the only thing I'll do I'm sure. I'm not doing "much" injector work! I've already made the line wrench and tried snugging down, but that made it worse, which is why I'm thinking either squashed gasket under the holder, or bad/cracked line end. I ordered parts ahead of time because I know how things tend to snowball.

I have found torque specs for the holders that say ~35 ft. lbs, is that correct?

thanks again fellas!

 

[MdStihl]

It can be done without pulling the pump. Use a19 wrench. If you have to turn the holders on both sides of the leaking one to make a normal wrench fit. Loosen and be aware that when you get to end of threads a spring will want to pop it off, so hold down on it. Pull out very carefully as there is little shim and springs and washers. Keep in exact order. Change oring on holder and reassemble. Careful not to over tighten. I did all 6 on my m4500 and I'm just a backyard farm mechanic whose cheap. My local injection shop told me I should do that. Any deeper in the pump and you'd need experience to tune and adjust settings.

Thanks Benjamin, I'll keep that in mind as well! And trust me, I ain't going any deeper!

 

[North Idaho Wolfman]

I'll of course make sure everything is TDC before I do that.

No need to do that, you can't get it timed wrong, the timing is done by the shims under the pump and no positioning of the up or fuel cam.

 

[thepumpguysc]

I just ran across this thread.. this autta be good.. I got my popcorn ready, keep us informed..
Just kidding.. Good luck.

 

[MdStihl]

Hah! I will try to disappoint I will for sure let you all know how it turns out.

 

[D2Cat]

MdStihl, take your time, have everything clean, have some cardboard under your working area just to be sure you can find something if it drops, take pictures as you go. You won't have any problems.

I think the comment thepumpguy made is designed to spook you, then you might hire him to rebuild the pump?

 

[MdStihl]

MdStihl, take your time, have everything clean, have some cardboard under your working area just to be sure you can find something if it drops, take pictures as you go. You won't have any problems.

I think the comment thepumpguy made is designed to spook you, then you might hire him to rebuild the pump?

nah, it's all good fun!

 

[North Idaho Wolfman]

I just ran across this thread.. this autta be good.. I got my popcorn ready, keep us informed..
Just kidding.. Good luck.

Pulling the pump on these is a walk in the park, nothing to really mess up doing that.

As long as he does not pull the rollers out of the bottom, he can't mess up the pump sync, pulling the delivery tops does not affect any of the adjustments on that model of pump, besides the torquing of the delivery valve holders which he already noted to know.
So watch a movie and eat your popcorn doing that, as nothing eventful is going to happen here besides fixing a leaking pump!

Now this does not hold true to all Kubota pumps, some pumps can and will get out of adjustment pulling the delivery valve holders.

 

[MdStihl]

So to update:
Got my WSM. Sure enough, not much info involving the pump, but IMO still worth the money at some future point. Hopefully never have to use it But you're right, it does look as if I just take out the "top" of the pump. I'm working on this a bit at a time, so I'll see what seems easiest.

I narrowed down the leaks by the use of an air hose. # 1, 4&5 are leaking at the base of the holders. No other leaks.

But I am replacing the valve cover gasket while I'm at it, it's oozing right along.

 

[MdStihl]

Okay, doing a followup for anyone else who might stumble upon this at some point.

I did not have to pull the injection pump. I replaced all the holders at the pump. They did not come with o-rings so got those at NAPA. I worked from left to right to install the new ones. I would install the holder, torque, then the fuel line. In this way I was able to always have a 19mm open end on the holder, while tightening the line nut. To torque with the torque wrench, I was able to get a socket on the holder with a knuckle joint that didn't bend much, just enough. Side note: the holders go in all the way very easily with fingers only, then once the oring makes contact just light snugging with a wrench until the o-ring seats. As soon as it stopped, I used the torque wrench, and it didn't take much at all to get it to click, maybe another 16th of a turn if that.

I used a dental pick to lay in the copper washer (gasket) over the spring. I could see myself dropping it inside.

I only have 1 leak remaining, which is the pipe end itself on #6 (or front). I've ordered a new one, since I'm fairly confident the end of the pipe is buggered someway. It's a very slight leak, but I didn't do all this to still have one. Another side note: you really don't have to kill the flare nuts tightening them down if everything is right.

Keeping things clean: I got everything around the holders blown clean before I started, and then kept up the cleaning as needed. Laid a clean rag over the holes. Then, before I started to install, I flowed fuel into the pump and let it come out the top, thereby flushing out anything I might have missed. It was the only way I felt sure I wouldn't have some particles that got in somehow.

I'm pleased with the end result (even though I have to replace the one fuel line, which for all I know has been leaking for a while) and I'd like to thank everyone for their good advice!