Cat 246C Fuel Injection Pump replacment

[mjones35]

Cat 246c SN JAY00979

5 Years ago my Cat 246c started spewing an oil and diesel mix from the valve cover breather tube. The problem turned out to be that the fuel injection pump seal had gone bad allowing fuel to enter the crankcase and mix with the oil. The Cat dealer pulled the engine, checked everything including the cylinder walls for damage, and replaced the pump and the problem was fixed. This cost over $9,000. Unfortunately, the same thing seems to have happened again. I caught the problem very soon after it started happening this time and don't intend to go through the expense of checking the engine for damage. I just want to buy a new pump, install it, and replace the engine oil (maybe twice). Can anyone give me an idea of how difficult this pump replacement would be? I know there is a gear on the pump with timing marks. Does this make it a lot more difficult? I'm trying to find a video on dealing with the timing issue, but haven't found one. I'm not a professional diesel mechanic but generally fix my own equipment if I can get to the parts without pulling the engine and no specialized diagnostic equipment is required.

 

[mjones35]

The part number for the pump is 249-7346. It doesn't have a gear installed and I actually don't know if timing is an issue.

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[Nige]

The part number for the pump is 249-7346. It doesn't have a gear installed and I actually don't know if timing is an issue..

That doesn't seem correct. The pump listed for for engine S/N CJS63846 is as fitted tomachine JAY00979 is a 317-4998. See attached.

The 249-7346 FIP is listed as fitting engines with S/N up to CJS60343 but your engine is higher than that. Please check your engine Serial Number.

Regarding the R&I for the injection pump does your engine have a water-heated cold start device or not.? In other words does it have hoses 1, 3, & 4 in this illustration.?

 

[mjones35]

I'll get out there today and check that engine SN and check for those hoses. 249-7346 is the part number of the pump that the Cat dealer installed when they repaired the machine in 2019 as listed on the invoice. Is it possible that 317-4998 is a replacement for 249-7346 that fixes the seal problem for certain engines? I've only put a couple hundred hours on that machine since the last repair and pump 317-4998 is about $2500 from Cat.

 

[Nige]

Is it possible that 317-4998 is a replacement for 249-7346 that fixes the seal problem for certain engines?

317-4998 is not listed as any type of update or replacement for 249-7346 as far as I can see. It was the first thing I checked. Both are still current, and unrelated, part numbers. Neither can I find anything about modifications or similar to either number to address internal leakages.

A “couple of hundred hours” in 6 years could have a lot to do with your problem, at least IMHO. Especially if there is a high percentage of biodiesel in the fuel you are using.

Instead of replacing the pump why not remove it and have it repaired by a pump specialist.? The forum has its own resident expert who strangely enough is not a million miles away from you. Send a PM to @thepumpguysc

 

[mjones35]

Nige, I checked the engine data plate and the engine SN that you listed is correct. I also rechecked the invoice for the repair that Cat performed, and they did install pump 249-7346, so I can't figure that out. The hoses 1, 3, and 4 that you noted in the diagram do not seem to be there. Does that affect the replacement difficulty?

If it's within my ability to remove and reinstall, rebuilding would be a good option. I'm quite a way from a Cat dealer and hauling it in and then picking it up is a pain. I can also get an aftermarket replacement for pump 249-7346 for about $800, but I can't find one for 317-4998. If pump 249-7346 was working, is it okay to stick with that part number?

The pump seems easy to access. I guess it comes down to how difficult it is to remove/install.

 

[mjones35]

Picture of the pump

 

[mjones35]

From above

 

[Nige]

I checked the engine data plate and the engine SN that you listed is correct.

In that case the correct fuel injection pump for that engine is 317-4998. See the attachment that I uploaded in Post #3. The title is "317-5047 PUMP GP-FUEL INJECTION .S/N CJS60344-70000". Your engine falls within that S/N range. The 317-4998 FIP is a part of the 317-5047 Group.

I also rechecked the invoice for the repair that Cat performed, and they did install pump 249-7346, so I can't figure that out. The hoses 1, 3, and 4 that you noted in the diagram do not seem to be there. Does that affect the replacement difficulty?

Why the dealer installed a pump from an earlier series of engine when they did the replacement I have no idea. The lack of the hoses actually makes the pump removal easier.

I would suggest that you contact the pumpguy by Private Message and provide him with the photos. He is the man to give you a definitive answer whether or not the pump is economically repairable.

Meantime I attach the R&I procedure for the pump. All the "sidebar" procedures such as finding TDC on #1 cylinder are included.

 

[reganj]

mjones35, re read post number 05, especially the last line.

 

[thepumpguysc]

I wrote a reply YESTERDAY in a prvt conversation.. and forgot to hit SEND.!! Lol

 

[HarleyHappy]

Happens to me all the time, sometimes fortunately as the next morning, I look at the post and ask myself how many drinks I had, the evening before. lol

 

[mjones35]

Just wanted to thank Thepumpguysc for replacing the seal on my fuel injector pump and for helping me to get the timing set correctly. I installed the repaired pump today, bled the fuel injector lines, and it cranked and ran perfectly.

I am having a problem unrelated to the injector pump though. Because the oil had been diluted with diesel, I drained all of the diluted oil. My intention was to fill it with new oil, run it for a few minutes, drain it again and then install a new filter and fill it with new oil again. Unfortunately, after draining most of the diluted oil, something seems to be clogged with my oil drain line. I poured in a couple quarts of oil with the stopcock open and nothing is draining. I blew some air back through the oil drain hose, and then more highly diluted oil drained but stopped after about a quart. I have now added 6 quarts of oil but can get nothing to drain through the stopcock and oil drain hose even if I blow air back through the hose. The dipstick still seems to be showing that there is diluted oil down there. Any suggestions on what could be preventing me from draining the oil? Can I feed the hose of an oil extractor all the way down to the lowest point?

 

[B&B]

Just wanted to thank Thepumpguysc for replacing the seal on my fuel injector pump and for helping me to get the timing set correctly. I installed the repaired pump today, bled the fuel injector lines, and it cranked and ran perfectly.

I am having a problem unrelated to the injector pump though. Because the oil had been diluted with diesel, I drained all of the diluted oil. My intention was to fill it with new oil, run it for a few minutes, drain it again and then install a new filter and fill it with new oil again. Unfortunately, after draining most of the diluted oil, something seems to be clogged with my oil drain line. I poured in a couple quarts of oil with the stopcock open and nothing is draining. I blew some air back through the oil drain hose, and then more highly diluted oil drained but stopped after about a quart. I have now added 6 quarts of oil but can get nothing to drain through the stopcock and oil drain hose even if I blow air back through the hose. The dipstick still seems to be showing that there is diluted oil down there. Any suggestions on what could be preventing me from draining the oil? Can I feed the hose of an oil extractor all the way down to the lowest point?

Can you unscrew the drain hose from the engine?

 

[ThreeCW]

Or can you feed the oil extractor suction line into the drain hose and see if you can "extract" the obstruction?

Did you receive any sludge back with the highly diluted oil?

It will be worthwhile to cut open your old oil filter than was used with the highly diluted oil to see if it provides any clues to what the problem is stemming from.

 

[Nige]

I have now added 6 quarts of oil but can get nothing to drain through the stopcock and oil drain hose even if I blow air back through the hose.

Has your oil pan drain port been modified in some way.?
The parts manual simply shows a plug and a washer, not a stopcock. I think some disassembly might be in your future.

 

[mjones35]

Really embarrassing, but I discovered that drain plug last night. I was draining the coolant which turned out to be really low and was also brown because someone had mixed in some green coolant with the Cat red coolant. I was also draining it into the oil that I dumped out of the filter, so didn't notice it was coolant. I've now actually drained the diluted oil and replaced with new oil and a new filter. Fortunately, I had a bucket of Cat coolant so that has also been replaced. Everything is good now. Sorry for my brain-dead post and thanks for the help.

 

[Simon C]

Most people have done similiar things, especially if tired or stressed out. Most people hit the delete button on their memory just like a digital camera, that way they never done that.
Simon C

 

[mjones35]

Thanks. I'm just fortunate to have the help and advice from all of the knowledgeable folks on this forum. I'm just a retired software developer.

 

[Nige]

Don't be too hard on yourself. The man who never made a mistake never made anything......

Question: Do you have an Operation & Maintenance Manual.? They are not expensive in the grand scheme of things. The Cat Publication reference is SEBU8019. Sometimes you can find used copies online but often at higher prices than a new one from the OEM.