Link Belt 330 fuel dilution of the engine oil

This topic contains 5 replies and was last updated by shawn-hawkins 8 years 9 months ago
April 8th, 2013 4:45am
Hello all, I'm a Cat field tech. A customer of mine has a 330 link belt, with a serious fuel dilution issue, elivated engine oil . I would think the fuel transfer pump would be the first thing to look at.. The customer had his mechanic replace the fuel transfer pump and they have the same problem, now they have asked me to check it out. (the crank case is very full coming out the breather and fill tube.) Was just curious about common Link-Belt Isuzu 6HK Engine problems, with fuel dilution. They say it runs good when running. Thanks I will be checking this unit out in a few days.
April 8th, 2013 9:16pm
The thought of the lift pump was a good one, and you have now eliminated one cause.

Other possible areas:

- a cracked or leaking fuel rail or jumper line.

- a leaking injector body.

- or if equipped with a heat exchanger for the fuel system, an internal leak.

Method that I have used in the past, is rig up a small circulating pump with the lines from the lift pump to the fuel system, and a hose return from the engine return line. Hook everything up to a five gallon pail of fuel.

Then using a dye that is visible to a black light, circulate the fuel through the engine. The leak will then become visible with the black light.

Once you have found and repaired the leak, the oil will need to be changed three times in short order to get the fuel out. The engine may already have serious engine bearing damage, more will occur if you try to cheap out. The diesel fuel has to go.

Hope you correct the problem.
April 10th, 2013 4:17pm
Thanks Jim, I went out on this unit Monday the 8th I removed the valve cover for inspection and ran for a short time , found a fuel return jumper line had a banjo fitting seal leaking internally. Repaired the return line seal, I changed the oil and filter , cut the filter and checked the paper media for debris, it looked good i advised the customer to change the eng. oil 10 hrs. of operation and then again in 40 hrs. . i will pull a oil sample for analysis

also asked the customer to frequently check the oil level for the next few days.. Thanks again
April 10th, 2013 4:34pm
Jim, Can I ask what company your with? I have read several of your replies in the past, you seem to have alot of great thoughts and knowledge! Thanks
April 10th, 2013 8:05pm
He's not a "Supreme Mechanic General" for nothing. Without disclosing his personal matters, Jim is one of our top Techs here on this site and we are fortunate to have someone with his yrs of experience sharing and helping others....... many thanks Jim.......Mechanics Hub Admin
April 11th, 2013 11:59pm
Thanks for your votes of confidence. As most of you know, I have been retired for over 2 years now. I am in the process of buying a house on the lake to enjoy myself.

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