Cat 374 Excavator build

[supraman]

This is the pump i will try , i am told it is out of a 125 4 stroke . I have just done a drawings for the inlet-outlet hsg with an internal bearing support as the original was plain bearing and added a seal on the output shaft as previously any leaked oil stayed inside the motor and was probably used to lube the input shaft in the plain bearing .. .
RCP57 has given me hope it will work ( maybe not the best ,,, but ) . If nothing else it will cost me nothing other than time to find out ,, plus i find it interesting

[RCP57]

Is that out of a Honda by chance? It looks exactly the same as the 50 pump other than the gears are thicker for more volume. See what I mean about the rounded teeth? I don't think this works well for extreme pressure and is probably why the Jung and other high pressure pumps have smaller, sharp teeth. I am able to get 250psi out of the oil pump fairly easy but beyond that the volume drops off significantly as the pump starts to slip. Hopefully you can do better with yours and as you said it is no loss to try other than your time. If you can make it work then you can say that you did it all on your own as well which is worth something in my mind. I don't know if you have access to one cheap but you may try finding a convertible top pump from a car. I bought one when I built my Volvo but didn't use it because the motor sucked juice like crazy. Inside though, it had gears almost identical to the Jung pump. It might be worth a try getting one for the gears and then your pump will for sure make the 400-500psi your machine will likely need.

Take my advise with a grain of salt though. I'm not a hydraulic expert by any means.

Reg