Cummins engines that utilize the PT fuel system as well as Cummins Celect engines, all have non-ferrous tubes fitted and machined into the cylinder heads to accommodate the fuel injectors. These tubes or sleeves are usually a copper, brass or stainless steel material and separate the lower half of the injector from the engine's coolant system.
Occasionally, these tubes crack or leak and must then be replaced.
Leaking injector tubes are often discovered when one or more injectors are removed from the cylinder heads perhaps during a fuel system service or other unrelated work. The evidence is engine coolant leaking directly into the cylinder on top of the piston. Clearly, this must be rectified.
If injector sleeves crack across the injector seat, combustion gases can enter the area between the injector and the sleeve and will soon cause further serious damage to the engine including pressurization of the fuel system or seizing the injector into the head. If the sleeve cracks to the water jacket or the o-ring sealing the tube to the head itself leaks, then fuel will contaminate the cooling system.
You should always check the external surface of the lower half of a PT or Celect injector for heavy carboning - especially as compared with other injectors in the same engine. This will give you a strong indication of an injector sleeve failure or an injector not seating in the sleeve for other reasons.
Replacing a leaking or cracked Cummins injector sleeve sleeve involves removal of the old sleeve from the head with specialized tooling; cleaning the area and installing and clamping a new sleeve into position; rolling that new sleeve to ensure a proper seal on the external oring; machining the injector seat are within the sleeve to a prescribed depth to ensure accurate injector spray cup (nozzle) positioning in relation to the relevant piston.
This service of available through Torquepower's service department for all Cummins engines fitted with copper/brass injector sleeves. This includes the longer injector sleeves fitted to NH and earlier six cylinder engines and excludes the stainless steel sleeves fitted to some M11 engines.
So, give us a call when you or your mechanic require that service and we will be pleased to assist you however we can.