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Jeremy, Certified Truck/Bus Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 3382
Experience:  ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician
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Es un freightliner columbia motor mercedes con problemas de

Customer Question

Es un freightliner columbia motor mercedes con problemas de arran que cambie mangueras succion desde el modulo hasta los tanqes luego cambie la bomba y manguera superior de succion. mejoro pero seguia descargando el fuel a los tanques y luego me di cuenta
que la valvula chek estaba leakeando estoy por cambiar eso y un injector malo para mañana probar
Submitted: 2 years ago.
Category: Medium and Heavy Trucks
Expert:  Jeremy replied 2 years ago.

HERE Guide to test the fuel pressure

HERE Look for the return line check valve. If it is bad, it will not let the pressure stay in the rail for the injectors. It happens a lot on these engines.

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Customer: replied 2 years ago.
Sigo con el problema de que se me regresa el fuel a los tanques este truck deberia tener alguna valvua de retencion para el retorno del fuel donde y si la tiene donde estará
Expert:  Jeremy replied 2 years ago.

The return line check valve is bad and needs to be replaced.

It is on the return line next to the fuel filter coming off the fuel rail of the engine. Replace that valve.

Customer: replied 2 years ago.
Este filtro solo tiene una vavula check en la salida del filtro a la manguera de retorno pero actua para no dejar que el filtro se vacie cuando reemplazas la manguera de retorno no es ninguna valvula de retencion . ahora veo que tambien esta succionando aire le elimine dentro del sistema probe eliminando el filtro separador de agua y conecté directo una manguera al modulo a un recipiente con diesel y sigue jalando aire dentro del sistema
Expert:  Jeremy replied 2 years ago.

If you are getting high air coming out, the issue could be at one of the injector pumps. That happens a lot on a MBE engine. The pump will crack on the bottom and will pull in air.

Customer: replied 2 years ago.
Ok voy a sacar las 05 bombas restantes para chequear los o'ring's pero no encuentro hasta ahora ninguna valvula de retencion en ese sistema no estara perdiendo presión por que no esta cerrado el sistema con la entrada de aire
Expert:  Jeremy replied 2 years ago.

Let me know what you find on the pumps.

I'm just hoping there is no issue with the high pressure fuel pump. Seams like the issue you are having though is aeration or air in the system. Check the pickup tubes at the tanks as well to see that there is no leak by running fuel from a bucket.

Customer: replied 2 years ago.
Cambie los o'ring's all five pumps y el aire persiste into the fuel sistem im tired ¿ es posible que la valvula chek y de retención esten dentro del filtro separarador . Yo hice un bypass de este filtro y contiua el problema .mañana tendré que poner directo a la bomba primaria usted que piensa deme algo
Customer: replied 2 years ago.
Las bombas estan en buen estado yo cambie los o'ring's y las instalé
Expert:  Jeremy replied 2 years ago.



I don't know what engine you have, but those are the guides. You have a unique problem. If the issue can't be found in the pumps or the fuel going to the engine, then it can only leave the head gasket. It is hard without looking at the issue to diagnose it.

Customer: replied 2 years ago.
Engine model#OM 460 LA 2003 air leak into fuel sistem and fuel return free to fuel tank .when turn off engine and trate again runnig take longtime sometime use starting fluid for run im replace sucction hoses complete ,primary pump, bypass water separator and fuel tanks, injectors pump oring's and the air persist wat you tinkg
Expert:  Jeremy replied 2 years ago.

I'm stuck. There is a crack somewhere in the pickup tubes or there is a head issue. You bypassed everything so all that is left is a crack in the pick up tube in the tank. I don't know what else it could be at this point. :-(

Customer: replied 2 years ago.
Elimine los tanques y el filtro separador de agua y conecté hose directo a la boma de transferencia y sigue cogien aire
Customer: replied 2 years ago.
Cambie la valvula de ventilacion y elimine la entrada de aire al sistema ahora me marca codigo de injector #5 vi que esta trabajando con presion la bomba de este injector ademas sigue demorando para arrancar solo lo hago con starting fluid para iniciar