Injector Leak off test

[Mick.source]

if i clamp the pipe then undo the banjo will air be drawn into the pump???

[Mick.source]

OK checked the Banjos tonight all OK, one thing i did notice is that i am getting a lot of air in the return pipe going back to tank, input is totally clear is this normal or could this be the problem?

[davidoft1]

OK checked the Banjos tonight all OK, one thing i did notice is that i am getting a lot of air in the return pipe going back to tank, input is totally clear is this normal or could this be the problem?

How was the filter in the return banjo ?

[ZsZ]

Leak-off test only works as a diagnostic process on newer diesels. Especially on CR systems.
On these old rotary pump systems you should check:

• the overall timing and the pump timing -> 0.9 +-0.5 mm is the factory pump time value, but 1.0mm gives a bit more power with a bit more smoke
  
• compression of the engine -> should be above 29bar IIRC
  
• pop test the injectors -> I am not sure about the pop pressure value
  

and if all those DIY doable tests are fine then send out the inj. pump for rebuild and calibrate. It is better to send in your injectors with the pump.