Most common places I see on 4-99, 4-107 and the 4-108 Perkins engines for fuel leaks are the fuel filter because people dont realise the two square section o-rings on a CAV style 296 filter are different sizes and then on the injector pump esp if its fitted with a Hydraulic governor DPA pump. Im rebuilding these pumps weekly and they mostly leak from either the throttle or stopping lever or the head o-ring. If the engines sit around for a very long time the driveshaft seals can and do leak but they fill the engines sump up before it coukd ever leak externally. Hardly ever see leaks from the lift-pumps either 2 or 4 hole flange type. Injectors rarely leak unless they have been played with.. Heres a tip for people running the Hydraulic governor pumps: the return fuel from the front of the injector pump normally from the factory goes back into the top of the fuel filter housing. Thats a big no-no. Nice n tidy for the factory to do it that way but it should go straight back to the fuel tank.
Why shouldn't it go back to the top of the fuel filter? Encourages more fuel than should be in the system? Mine does that and I am curious whether I should go to the trouble to switch it.
@@glened1 On any hydraulic governor pump the fuel coming out of the return fitting is going to be aerated. Pump it into the head of the fuel filter and air will find its way into the injector pump causing hunting, surging, sumtimes sluggish to come back to idle. The factory plumbs it into the filter cos its neat n tidy for them and they will never see the engine come back by the time it causes an issue. Been returning straight back to the tank in hyd gov pumps for a looong time now. Has cured issues everytime. Not a big deal to do.
@@matui6983 Awesome info. Thank you! We may be attempting some seal fixes on our hydraulic injection pump and will propose this as an additional one. Thanks very much!
@@glened1 Is it leaking from the throttle or stopping lever? If its a mechanical governor DPA pump its an easy fix for both. The hydraulic governor DPA has 2 x different types of housings depending on wether its a 4 or a 6 cylinder engine. One can be done in situ ( most 4 cylinders) the 6/354 pumps have a non reversible gov housing that realky needs the pump removed from the engine to be done 100% correctly. Literally doing a 6/364 leaking pump right now. Please dont use Chinese overhaul/gasket kit. Waste of time. Delphi or Spaco brands only two worth using.
Most common places I see on 4-99, 4-107 and the 4-108 Perkins engines for fuel leaks are the fuel filter because people dont realise the two square section o-rings on a CAV style 296 filter are different sizes and then on the injector pump esp if its fitted with a Hydraulic governor DPA pump. Im rebuilding these pumps weekly and they mostly leak from either the throttle or stopping lever or the head o-ring. If the engines sit around for a very long time the driveshaft seals can and do leak but they fill the engines sump up before it coukd ever leak externally. Hardly ever see leaks from the lift-pumps either 2 or 4 hole flange type. Injectors rarely leak unless they have been played with.. Heres a tip for people running the Hydraulic governor pumps: the return fuel from the front of the injector pump normally from the factory goes back into the top of the fuel filter housing. Thats a big no-no. Nice n tidy for the factory to do it that way but it should go straight back to the fuel tank.
Fantastic advice, Thanks for sharing your knowledge on these engines.
Cheers
LDW
Why shouldn't it go back to the top of the fuel filter? Encourages more fuel than should be in the system? Mine does that and I am curious whether I should go to the trouble to switch it.
@@glened1 On any hydraulic governor pump the fuel coming out of the return fitting is going to be aerated. Pump it into the head of the fuel filter and air will find its way into the injector pump causing hunting, surging, sumtimes sluggish to come back to idle. The factory plumbs it into the filter cos its neat n tidy for them and they will never see the engine come back by the time it causes an issue. Been returning straight back to the tank in hyd gov pumps for a looong time now. Has cured issues everytime. Not a big deal to do.
@@matui6983 Awesome info. Thank you! We may be attempting some seal fixes on our hydraulic injection pump and will propose this as an additional one. Thanks very much!
@@glened1 Is it leaking from the throttle or stopping lever? If its a mechanical governor DPA pump its an easy fix for both. The hydraulic governor DPA has 2 x different types of housings depending on wether its a 4 or a 6 cylinder engine. One can be done in situ ( most 4 cylinders) the 6/354 pumps have a non reversible gov housing that realky needs the pump removed from the engine to be done 100% correctly. Literally doing a 6/364 leaking pump right now. Please dont use Chinese overhaul/gasket kit. Waste of time. Delphi or Spaco brands only two worth using.