BOBCAT 743B kobota engine diesel in crankcase

pepe467 · Dec 7, 2016

Can anybody give me some advice on my BobCat 743B model I am getting diesel in the crankcase.

thank you

Dieseltech · Dec 7, 2016

Does the injection pump have an aluminum body, with two five point star head bolts holding each outlet flange? If so the pump may need resealed, the lower flange O rings can leak fuel into the oil. External leaks are usually the top O rings. Zexel is the pump maker, formerly Diesel Kiki.

Al Baker(pumpman) · Dec 8, 2016

Sounds to me like time for a reseal. Call around and explain your problem. Reseals are not real expensive, but sometimes necessary. Using the internet, and mailing a pump away can sometimes save lots of cash compared to picking someone who is a close drive. Ask how long of turn around each shop has. I try to turn a pump in a few days which soots most guys fine. Have heard stories of shops telling guys they are three weeks behind. This is ok if you are not in any hurry, but sucks if you need this machine. Couple of minutes on the phone asking questions most times will make you much happier with the end result. Al 231/757/0064

AJ. · Dec 8, 2016

I seem to think that the pump fitted to those engines was an in-line plunger type operated by the engine camshaft,the pump can be removed and replaced without worrying about timing providing the same shims are used when replacing the same pump otherwise it should be spill timed,it is unusual for them to leak fuel into the oil,if they do it indicates the pumping elements are worn,if they are it must have a lot of hours done or the fuel was contaminated,some of the older engines had a thermostart plug in the intake manifold,the later ones had glow plugs,if you got the thermostart plug check it,usually the feed pump was electric but some had mechanical,if its mechanical that can leak in,is the engine running smooth esp after start up,does it smoke esp when idling,if it does have the injectors serviced as they may be dribbling and the fuel can get in that way,if those things check out you will need to have the pump serviced.
AJ

Dieseltech · Dec 8, 2016

Some Zexel pumps look like miniature Bosch MW or P pump, and have an upper and lower O ring on each barrel holder. I reseal a lot of them that the lower O ring allows fuel into the oil. These are PFR type pumps that use a separate camshaft in the engine.

BOBCAT 743B kobota engine diesel in crankcase

pepe467

New User

Dieseltech

Well-known Member

Al Baker(pumpman)

Member

AJ.

Well-known Member

Dieseltech

Well-known Member

Similar threads