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DT239 injector question


Duntongw
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My nephew has a Dresser TD8E dozer with a DT239 turbo'd engine.

He has an injector that keeps bleeding up out of the bore around the injector. He has pulled injector and cleaned it and bore but no luck. Is there supposed to be some kind of crush seal of some sort down in there? Any help would be appreciated.

Thank you in advance

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18 hours ago, Duntongw said:

keeps bleeding up out of the bore around the injector

What is it bleeding? If diesel fuel, then injector needs to be pulled and serviced. If compression then the taper on end of injector and possibly the mating taper of nozzle sleeve needs attention. (2) different styles of injectors in those engine, but both use same nozzle sleeve in cylinder head and neither one use a compression sealing washer at bottom end. 

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I assume you mean its bleeding compression? There is no crush washer or seal on those. There is an O-ring but it is just there to keep dirt and moisture from getting between the injector and the injector sleeve.

The injector seals combustion by the injector retaining bolts or clamp pushing it down into the sleeve. I have seen the sleeves get distorted or damaged and have difficulty sealing. Here is a picture of the new injector sleeve about to be installed on mine.

20190316_132047.thumb.jpg.bd942d04780321f1d053ac23aff4d8a8.jpg

Then the rebuilt injector about to be installed. The orange O-ring is just the dust seal. The tapered lower part of the injector seals against the inside tapered lower part of the injector sleeve.

20190316_142337.thumb.jpg.81a1b06144ec1934473298f6e7f6f03d.jpg

If left leaking combustion for a long time soot will build up between the injector and sleeve resulting in this... The sleeve pulled out (with great difficulty) with the injector. When the sleeve breaks loose coolant is allowed into the cylinder.

20190217_154831.thumb.jpg.02af88f993dacace156abdca6e91a3b4.jpg

I hope these pictures help.

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Thank you for your reply. There does not seem to be any compression bleeding thru. Once it is cleaned and reassembled, within 20 seconds of starting the engine, you will see fuel begin to fill up around the top of the injector bore. It was worse prior to cleaning, but still bleeding, so I assume that it must not be bleeding fuel out of the injector itself, unless a different amount of clamp pressure could alter this. I see that the injector is multiple parts, can it be leaking thru one of these joints?

One other injector was also bleeding fuel, but cleaned it and got it to stop.

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I see.

I did have one injector that leaked through the joint in the middle of the injector. I had taken them to a questionable injection shop since my usual local injection shop closed when the owner retired. It leaked slowly where the two halves come together when I got it back.

Other possibility is the line into the top of the injector isn't seating properly into the taper. Or the small rubber return line banjo fitting and crush washers are leaking and pooling below.

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23 hours ago, CIHTECH said:

What is it bleeding? If diesel fuel, then injector needs to be pulled and serviced. If compression then the taper on end of injector and possibly the mating taper of nozzle sleeve needs attention. (2) different styles of injectors in those engine, but both use same nozzle sleeve in cylinder head and neither one use a compression sealing washer at bottom end. 

My apologies for incorrect advice. The engine we had with a compression leak was not a 239. Was a long time ago. 

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