APS Racing Products

How high of pressure is there in a diesel fuel injection return line?

I know rail pressure in a diesel engine is 15kpsi easily, and I assume there is a fuel pressure regulator attached to a return line that goes back into the tank or back in before the high pressure fuel pump. My question is, if you cut off the flow in the return line, could the pressure build up to the bursting point of the hose?

Public Comments

1. Some diesel engines use a shutoff valve in the injector pump return line to stop the engine. Most high pressure systems are designed to withstand at least 50% more pressure than they could possibly see in service.
2. pressure in the return line is very minimal you do not have a restriction in that line after the pressure regulator. if you have a blockage in that line before the tank it can develop pressure but the chances of that happening are next to none.