You CAN repair a leaky fuel injector pump! PICS and a question.

[D2Cat]

KYKub

I had a small leak in my fuel injector pump and read that self-repair of these units is impossible, or at least strongly discouraged. Having a brother that is a good mechanic and can bail me out of most of the messes I create, I figured I would give it a shot. My repair was to a 3 cylinder Kubota (D722), but I think the same basic process would work on any Kubota diesel engine. This seems to be a fairly common problem so I hope it saves some time and money for others.

The leak was around the base where the injector lines connect to the pump. Slow leak, but over time builds up oily junk down the side of the engine. The problem is failing O-rings on the shaft of the injector. 2 O-rings on each shaft. Here's what I did: ....zip




Thank you thread starter KYKub - your posting is appreciated!

I have exactly the same fuel leak in my Kubota F3060 mower (Kubota V1305 engine), and was able to find the O-rings on the eBay with the dimensions you gave by searching: Viton/FKM O-ring 11.8 x 2.4mm Price for 10 pcs


:jump:

From what you describe you have fuel leaking at the injection pump delivery valves. If one is leaking I would replace them all while your there.

I would use o-rings from the dealer. They typically cost about .90 each. The benefit is you know they are correct for your application.

You can go to this site and agree to the legal part and then look up your model machine and find every part on it. Kubota Tractor Corporation - Illustrated Parts List

You can also print off the parts associated with in area so you have a heads up on what is in there. Be sure to have the area cleaner then your (pre-used)dinner plate!

 

[D2Cat]

KYKub

I had a small leak in my fuel injector pump and read that self-repair of these units is impossible, or at least strongly discouraged. Having a brother that is a good mechanic and can bail me out of most of the messes I create, I figured I would give it a shot. My repair was to a 3 cylinder Kubota (D722), but I think the same basic process would work on any Kubota diesel engine. This seems to be a fairly common problem so I hope it saves some time and money for others.

The leak was around the base where the injector lines connect to the pump. Slow leak, but over time builds up oily junk down the side of the engine. The problem is failing O-rings on the shaft of the injector. 2 O-rings on each shaft. Here's what I did: ....zip




Thank you thread starter KYKub - your posting is appreciated!

I have exactly the same fuel leak in my Kubota F3060 mower (Kubota V1305 engine), and was able to find the O-rings on the eBay with the dimensions you gave by searching: Viton/FKM O-ring 11.8 x 2.4mm Price for 10 pcs


:jump:

From what you describe you have fuel leaking at the injection pump delivery valves. If one is leaking I would replace them all while your there.

I would use o-rings from the dealer. They typically cost about .90 each. The benefit is you know they are correct for your application.

You can go to this site and agree to the legal part and then look up your model machine and find every part on it. Kubota Tractor Corporation - Illustrated Parts List

You can also print off the parts associated with in area so you have a heads up on what is in there. Be sure to have the area cleaner then your (pre-used)dinner plate!

 

[arto98607]

From what you describe you have fuel leaking at the injection pump delivery valves. If one is leaking I would replace them all while your there.

I would use o-rings from the dealer. They typically cost about .90 each. The benefit is you know they are correct for your application.

You can go to this site and agree to the legal part and then look up your model machine and find every part on it. Kubota Tractor Corporation - Illustrated Parts List

You can also print off the parts associated with in area so you have a heads up on what is in there. Be sure to have the area cleaner then your (pre-used)dinner plate!

Thank you - those spare part diagrams are also available on the Messick's website, but unfortunately Kubota is not offering the internal fuel injection pump parts individually.
They would sell a new pump for over $1100 though, or alternatively rebuilt pumps can be bought from eBay vendors for less then half of that.

I have a set of Viton O-rings and will report once they have been installed.

 

[D2Cat]

Interesting you say Kubota is not offering the internal fuel injection pump parts individually. You can't get all the internal parts but they do have the o-rings. I just installed 4 a week ago. Got them at Coleman Implement, Bonner Springs, KS.

If you need a complete pump you can contact these folks. They have good prices, service and delivery. Oregon Fuel Injection | Diesel Parts | Rebuilt Diesel Injection Pumps

 

[arto98607]

Interesting you say Kubota is not offering the internal fuel injection pump parts individually. You can't get all the internal parts but they do have the o-rings. I just installed 4 a week ago. Got them at Coleman Implement, Bonner Springs, KS.

If you need a complete pump you can contact these folks. They have good prices, service and delivery. Oregon Fuel Injection | Diesel Parts | Rebuilt Diesel Injection Pumps

Thank you, that's good to know - it looks like a good Diesel shop!


Do you have any suggestions or tips on how best to mark the position of each delivery valve, in order to reinstall it in the exact same spot (IE to prevent rotating them) and maintain the amount of fuel delivery for each?
(I would hate to have to scribe permanent marks in the metal but...)

I know a Diesel shop could re-calibrate the pump delivery but I am trying to avoid going there this time.


:wink:

 

[D2Cat]

Arto, here's the process I'd recommend. Begin by cleaning the lines from the injectors to the top of the injection pump with something like brake cleaner. Remove the vibration isolation clamps holding the injection lines in place. Loosen the nuts at the injectors. Loosen the nuts at the other end of the injector lines at the top of the injector pump. Be sure to use a wrench to hold the nut at the IP while turning the nut on the injection line.

If you're working on an engine with more then two cylinders (two lines) you have to start one of the outside delivery valves so you can get to the next one. Does not matter at which end you start! (That is why it's best to replace all the o-rings at the same time).

As you get the nuts loose at the IP, and you have the nuts loose at the injectors the lines can be picked up and removed. Lay them aside on something clean, like a piece of cardboard. Now loosen the nuts you had the wrench on when you loosened the injector line at the IP. I'd loosen them but leave them in place until you have them all lose.

Now, carefully and gently pick up the nut on the outside edge (doesn't matter which edge) and set this nut on the cardboard. If your uncomfortable with the process, you might take an ink pen and mark 1,2,3,4 on the cardboard and put the nut by the appropriate number....front to back. This will insure you get the same parts to the place you removed them.

Now under the nut is a spring similar to the spring in an ink pen, just stiffer. It may come up with the nut, so be careful to not drop it. There is also a small spacer that goes on top of the spring just under the nut that also fit into the top of the spring. It will stay in the spring if you gently remove the nut.

So when you remove the nut, have something underneath your work area, like cardboard, or an old sheet, so if you drop something you can find it easier. As soon as you get the nut unscrewed and pick it up off the threads, turn it over so you can see what in it.

Now you repeat the process for the other lines.

You remove the existing o-ring (usually easier with a pick of some kind), and install the new o-ring.

Put it all back together in the reverse process.

You local Kubota dealer should be able to give you a print out of all the part in the area you will be working. They have the o-rings, just ask at the parts counter. Might ask for "injection pump (component parts)" print out.

 

[arto98607]

D2Cat

Thank you - it sounds like the pump you worked on is little different model perhaps?

As I have read elsewhere, the one in Kubota V1305 engine has oval holes for the delivery valve hold-down flanges.
Their purpose is to allow fine adjustment of fuel delivery amount by rotating the valves.

Please see a photo of similar 3 cylinder engine pump by someone else below.

 

[doughboy1]

What does the pin do? I lost one. Will the engine still run if I put it together? Where can I order one?

 

[thepumpguysc]

DB1> the pin locates the barrel & is VERY important.. IF you removed or loosened the top piece, {delivery valve holder}.. the barrel has probably turned..??
Once u get the others tightened/torqued down, just use "their pin" to locate the barrel & torque it down.. its not need to run.. only for assembly.
I've heard of people using a drill bit to locate the barrel after loosing ALL the pins..
Good luck.
How are u guys loosening/removing & tightening the hold down screws?? chisel??

 

[JDDeuce B2400]

From what you describe you have fuel leaking at the injection pump delivery valves. If one is leaking I would replace them all while your there.

I would use o-rings from the dealer. They typically cost about .90 each. The benefit is you know they are correct for your application.

You can go to this site and agree to the legal part and then look up your model machine and find every part on it. Kubota Tractor Corporation - Illustrated Parts List

You can also print off the parts associated with in area so you have a heads up on what is in there. Be sure to have the area cleaner then your (pre-used)dinner plate!

I may be a little late on my reply, but, There is a place that has all sorts of rebuild parts and complete parts from a number of injector pumps out there. They are called Diesel Injector Pumps (catchy huh?). They are located in the UK and seem very knowledgeable. They take credit cards and also Pay Pal. Check them out!