Diesel Leak Injection Pump

[buddybear]

This is a continuation of my post Antifreeze Leak. I still have the antifreeze leak. It appears where I was finding the drip from the motor mount bracket was diesel. The top of the injection pump is wet with diesel, I thought it was antifreeze. The issue with this leak is that it doesn't occur when the engine is running or 8-10 hours later. after I have run the engine in the afternoon and check it the next morning I find the leak. It is not where the injection pump is mounted on the engine, but on top of the injection pump. I have looked at the parts breakdown and trying to determine what could be producing the leak. Hopefully someone with this same engine M25XPB has had this problem. I finally hired a mechanic who took the hose off the banjo fitting cut a small amount of the hose off loosened then tightened the banjo fitting and reattached the hose. Ran the engine no leak checked again at 11:30 that night no leak. In the morning next day diesel on top of the pump again. My theory is when the engine is hot metal expands as it cools metal contracts and then I see leaks. Have called the mechanic back and will see what he says. Any suggestions would be greatly appreciated, have been working on this for 3 weeks.

Thanks,
Mark

 

[Ralph Johnstone]

I finally hired a mechanic who took the hose off the banjo fitting cut a small amount of the hose off loosened then tightened the banjo fitting and reattached the hose.

You did not mention if the mechanic replaced the copper gasket in the banjo fitting. If he didn't, not impressed. Never trust a used copper gasket on diesel fuel.

Please post hi res pictures of your injection pump from numerous angles as I'm not familiar with it. Yanmar here. Both closeup and a couple of feet. I've never heard of a complaint where someone posted too many pictures for troubleshooting. The leakage is most likely coming from a steel tube fitting so let's see what's above the pump head, both HP and LP.

And ............................ don't pay the mechanic another dime when he suggests replaceing every high pressure joint on the engine. Leak finding is often a veeeeeeeeeeeery slow process which the mechanic cannot afford to stand around and wait for an intermittant leak to appear. Replacing everything is sometimes the cheaper way to go. Your time is free, and our advice is not much more expensive.

Pictures by the cartload .

 

[jssailem]

have been working on this for 3 weeks.

It happens. Patience. Look for the simplest answer: Ochum's Razor.

 

[buddybear]

It happens. Patience. Look for the simplest answer: Ochum's Razor.

You are so right, the more you analyze something the more complex the solution is.

 

[jssailem]

the more you analyze something the more complex the solution is.

No. It may be just more complex the problem appears.

There was a great song that helps me remember.
“It ain’t necessary so”

 

[Ralph Johnstone]

You are so right, the more you analyze something the more complex the solution is.

Yes, you're so right. But you DO get a solution, complex or not.
How are the photos coming so we can get a look at this beast ?

 

[Project_Mayhem]

Is it possible to do a pressure or vacuum test to check for leaks both when cold and when hot? Perhaps a simple soap/water solution with a pressure test when warm will reveal the leak. Another, probably more successful idea is to draw chalk lines around all potential spots for leaks. In the morning you should see those lines eroded by leaking diesel

 

[rpwillia]

A friend had a Westerbeke 4-cylinger engine (really a Mitsubishi) where the injection pump fitting for that rear most cylinder was leaking. I took the top part of the pump out and when looking at the o-ring it snapped off (it was dry rotted). Cost me $0.99 for a new 17 or 19mm one at the hardware store. Friend later remarked that not only was the leak gone, but it was running smoother than it ever had. ;-) If you look at the attached drawing you want to check out part 70 on your pump. This is a Kubota pump (which I think all the Universal's are), but do not worry they are all about the same.

 

[colemj]

If it is a marinized Kubota, then it is likely a Kiki injection pump (I think Bosch bought them years ago, so it is technically a Bosch pump now). O-ring 070 is a possibility and easy to change, but usually the problem with a leak here are the two #100 o-rings. These aren't so easy to change, and one can screw up the injection volume if they don't have a calibration jig to put it back together. The bolts holding the delivery valves in are security ones, so you need a proper bit. The exact rotation of flange 080 controls the delivery volume, so without a calibration jig, make sure to scribe index lines onto the flange and pump body so they go back in the exact rotational aspect to each other (and don't mix up the flanges). The valve body 020 slots into the retaining washer 170, and this can only be removed from the bottom of the pump.

If it was me, I'd just remove the entire pump and take it in to a diesel pump/injector shop for a complete refurb and rebuild for $300 or so. You will need to remove the pump anyway to replace those seals, and while it is out you should replace the seals in the other delivery valves, and you might as well refurb the other wearable parts in there like the rollers, retaining spring, crush washers, etc. Taking it to a shop will save you time and get back a clean, calibrated pump good for another 30+ yrs.

Mark

 

[buddybear]

If it is a marinized Kubota, then it is likely a Kiki injection pump (I think Bosch bought them years ago, so it is technically a Bosch pump now). O-ring 070 is a possibility and easy to change, but usually the problem with a leak here are the two #100 o-rings. These aren't so easy to change, and one can screw up the injection volume if they don't have a calibration jig to put it back together. The bolts holding the delivery valves in are security ones, so you need a proper bit. The exact rotation of flange 080 controls the delivery volume, so without a calibration jig, make sure to scribe index lines onto the flange and pump body so they go back in the exact rotational aspect to each other (and don't mix up the flanges). The valve body 020 slots into the retaining washer 170, and this can only be removed from the bottom of the pump.

If it was me, I'd just remove the entire pump and take it in to a diesel pump/injector shop for a complete refurb and rebuild for $300 or so. You will need to remove the pump anyway to replace those seals, and while it is out you should replace the seals in the other delivery valves, and you might as well refurb the other wearable parts in there like the rollers, retaining spring, crush washers, etc. Taking it to a shop will save you time and get back a clean, calibrated pump good for another 30+ yrs.

Mark

That is what I was thinking, to have it rebuilt. I am in Florida a shop quoted me $440. It definetly is not the banjo fitting or hose. Which delivery valve or all are leaking? A rebuilt should fix the issue.
Thanks,
Mark

 

[colemj]

That is what I was thinking, to have it rebuilt. I am in Florida a shop quoted me $440. It definetly is not the banjo fitting or hose. Which delivery valve or all are leaking? A rebuilt should fix the issue.
Thanks,
Mark

It's a Zexel pump, which used to be Kiki. They bought them out, not Bosch like I originally said.

I can't say from here which is leaking, but if you have it rebuilt, they all will get new seals and refurbishing.

Mark

Edit, I just looked and Bosch bought Zexel.

 

[buddybear]

It's a Zexel pump, which used to be Kiki. They bought them out, not Bosch like I originally said.

I can't say from here which is leaking, but if you have it rebuilt, they all will get new seals and refurbishing.

Mark

Edit, I just looked and Bosch bought Zexel.

It doesn't look that difficult to remove it. Anything I need to know before I try. Basically, is there something I can really screw up.
Thanks,
Mark

 

[colemj]

It doesn't look that difficult to remove it. Anything I need to know before I try. Basically, is there something I can really screw up.
Thanks,
Mark

Do you mean to remove the pump from the engine? If so, that is easy with only three points to be aware of:

1. Get the pump and area very clean before removing. You are going into the sensitive part of the fuel delivery system and any dirt will bite you. When the pump is out, put a lint-free rag in the empty hole, or cover it with plastic wrap, or do something similar. Don't worry about the pump itself, as that will be throughly cleaned and returned pristine (and without any paint).

2. Removing the pump just involves disconnecting the hoses and the bolts holding it on. But don't lift it straight out when it is all disconnected and ready. There is a clip inside connecting the fuel rack arm and if you pull it up, you can bend the arm. So lift it a little ways until you can access the rack arm and pull the clip off. Make sure you do not drop the clip into the engine body or that will be painful. Some people even tie a piece of string to it before removing. I just remove it with a clamped-on hemostat.

3. The pump is timed with shims between it and the engine body. You may have 0-3 of them. Most of the time they are obvious and stay back when the pump is lifted out, but sometimes the one adjacent to the pump body sticks to the pump and you don't notice it. You want to keep all of the shims because the service place might throw them out, and you need them to install the pump with correct timing. If you have more than 0-1 shim, the order of the shims doesn't matter - just the final height of the pump on the body.

Mark

 

[buddybear]

Do you mean to remove the pump from the engine? If so, that is easy with only three points to be aware of:

1. Get the pump and area very clean before removing. You are going into the sensitive part of the fuel delivery system and any dirt will bite you. When the pump is out, put a lint-free rag in the empty hole, or cover it with plastic wrap, or do something similar. Don't worry about the pump itself, as that will be throughly cleaned and returned pristine (and without any paint).

2. Removing the pump just involves disconnecting the hoses and the bolts holding it on. But don't lift it straight out when it is all disconnected and ready. There is a clip inside connecting the fuel rack arm and if you pull it up, you can bend the arm. So lift it a little ways until you can access the rack arm and pull the clip off. Make sure you do not drop the clip into the engine body or that will be painful. Some people even tie a piece of string to it before removing. I just remove it with a clamped-on hemostat.

3. The pump is timed with shims between it and the engine body. You may have 0-3 of them. Most of the time they are obvious and stay back when the pump is lifted out, but sometimes the one adjacent to the pump body sticks to the pump and you don't notice it. You want to keep all of the shims because the service place might throw them out, and you need them to install the pump with correct timing. If you have more than 0-1 shim, the order of the shims doesn't matter - just the final height of the pump on the body.

Mark

Thanks a lot, I am planning on having the mechanic remove the pump but if he will be a long time coming back I will do it.

 

[PlaneTom]

When I had my M25XPB injector pump rebuilt locally about 6 years ago, it was a bit over $500 parts and labor. At the time it was about 1/3 the cost of a rebuilt from the Universal dealer. Monterey, Ca isn't a cheap area for anything.
But it is a big agriculture production county. An industrial diesel shop in nearby Salinas had the parts for the pump already on the shelf. 3 days later it was back in the boat. I thought my engine started easily and quickly before, now it's even faster.
On mine, an internal spring had broken and fouled up the works. The engine was running fine as I was backing from the slip, and cut off almost instantly. It would crank fine, but no fire. I went through fuel filters, fuel pump, etc, and found good flow right up to the injector pump inlet. When I pulled off the injector lines from the pump, nothing at all came out.
The secondary effect of the pump failure was it was dumping fuel into the sump. By the time I realized that, the oil was a milky grey color and way overfull. It hadn't run long like that, so I didn't suspect any bearing damage in the engine. I did three drain and refills of the oil before I got the injector pump back. Once it was running again, I ran it on clean oil for 10 minutes to circulate that, then drain and refill. Three cycles like that and the oil stayed clean. I thanked the previous owner multiple times for installing the fluid pump on the drain line from the sump. It's mounted on the back bulkhead behind the engine, put that pump outlet tube into a container, put my cordless drill driver on the fluid pump shaft and spin away, and in a couple minutes the engine oil is completely removed with no mess.
I can change the oil on the boat faster than I can on my car, and with less mess.

 

[buddybear]

When I had my M25XPB injector pump rebuilt locally about 6 years ago, it was a bit over $500 parts and labor. At the time it was about 1/3 the cost of a rebuilt from the Universal dealer. Monterey, Ca isn't a cheap area for anything.
But it is a big agriculture production county. An industrial diesel shop in nearby Salinas had the parts for the pump already on the shelf. 3 days later it was back in the boat. I thought my engine started easily and quickly before, now it's even faster.
On mine, an internal spring had broken and fouled up the works. The engine was running fine as I was backing from the slip, and cut off almost instantly. It would crank fine, but no fire. I went through fuel filters, fuel pump, etc, and found good flow right up to the injector pump inlet. When I pulled off the injector lines from the pump, nothing at all came out.
The secondary effect of the pump failure was it was dumping fuel into the sump. By the time I realized that, the oil was a milky grey color and way overfull. It hadn't run long like that, so I didn't suspect any bearing damage in the engine. I did three drain and refills of the oil before I got the injector pump back. Once it was running again, I ran it on clean oil for 10 minutes to circulate that, then drain and refill. Three cycles like that and the oil stayed clean. I thanked the previous owner multiple times for installing the fluid pump on the drain line from the sump. It's mounted on the back bulkhead behind the engine, put that pump outlet tube into a container, put my cordless drill driver on the fluid pump shaft and spin away, and in a couple minutes the engine oil is completely removed with no mess.
I can change the oil on the boat faster than I can on my car, and with less mess.

Thanks for the info