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