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Komatsu D57S injection chamber leaking

James Sorochan · 2022-07-19 14:59

Hi all. Finally found some time to work on the machine. It was starting to leak around one of the chambers. I’m no expert so if everyone can give me some advice it would be appreciated. I took some pictures to show you where things are at. One thing I noticed is the injector nozzle tip is almost non-existent. Not sure if that’s normal for this machine. ( serial no. 09571 ) The engine is a S4D130-1 ( serial no. 29040)

Replies7
  1. #1James Sorochan2022-07-19 15:02

    Some more pics

  2. #2James Sorochan2022-07-19 16:12

    Cleaned up the first chamber out. Does anyone know if the bottom where the injector sprays into pops up into and comes out top? Do I need to get this into a really good parts cleaner or do I take everything into a injection shop and get them to go through everything?

  3. #3James Sorochan2022-07-24 10:40

    Cleaned up the injectors; chambers; bolts and spacers. The chamber bolt holes were full of junk so I filled them up with penetrant oil and used a gun barrel cleaning wire brush on a drill to clean them up. Worked good until the brush broke off in the last hole towards the cab. There was no room to pick it out so I ended up drilling and using a tap to pull it out. Inside the chamber there is a copper stepped insert that seals against the injector nozzle. I noticed some nicks on it. Is this going to be a problem? I’m not experienced in these things. If there is going to be a problem what’s the solution? The motor was rebuilt back in the 90’s but I don’t know if the injectors got serviced then. I’ll post three pics. The injector/chamber….chamber copper insert…… and injector tip. Thanks

  4. #4thepumpguysc2022-07-24 12:16

    On the injector itself, the tip is called a throttling pintle nozzle.. The more fuel that’s going into the injector, the higher the pintle raises to give more fuel.. They are VERY SENSITIVE.. DO NOT RUN IT ON A WIRE WHEEL.!! As far as your leaks go, u have a book for the breakdown.. simply replace the gaskets/oring.. Good luck..

  5. #5James Sorochan2022-08-11 00:01

    Update. Installed new copper gaskets and orings on the chambers. Threaded the nozzles back into chambers and put back on machine. One of the nozzles was leaking up out of the threads so I pulled everything off and tightened the nozzles one turn on all of them, reinstalled and no leaks. Ran engine up to temp and still no leaks. One thing though......There is what seems like water coming out the blow by tube. A drip every few seconds. There is also a bit of blow by mixed in. When I pulled one of the chambers I didn't have the coolent drained down enough and got some on top of the piston so i vacuumed it out. Would this cause a problem? I'm going to crack the drain plug in the morning and see if there is any coolant. any ideas?

  6. #6James Sorochan2022-08-11 13:59

    Cracked the oil and lug just now. No coolant. I measured the coolant level in radiator and will work the machine for an hour or so. I’ll let it sit over night again and recheck everything tomorrow. Any other suggestions ? The oil seemed ok to me but I’ll get a second opinion from someone with a better noise than me.

  7. #7James Sorochan2022-08-13 20:47

    Well I guess I over reacted. Just blow by. I thought it was steam but after putting my hand under vent tube it was just hot but not wet. Running good. I do have a question if anyone can answer. The alternator is putting out 34volts on the top wire which I believe is for starting. I just had it into the rebuild shop and they said they changed out a diode. After I put it back on it was good but the alt light came back on only after an hour or so. Is there still me thing on the machine that would cause this? Thanks