Komatsu pc 30-3 hydraulic pump problem

[anuradha]

Hi every one,

One of my friend has done some works on the pump of komatsu pc 30-3 . i still did not get the serial number yet.
They have replaced all the orings(seal kit) of the pump and have polished both sides of these two parts using a ameri paper. (Picture shows only one part )

After reinstalling the pump now machine pressure seems like build up.But the problem is now these o'rings in the picture gets damaged and oil is leaking. ( from the both plates )
May i know the possible causes for this issue ?


Thank you.

 

[John C.]

I've seen plenty of reasons for that on gear pumps. Plates installed turned around. Seal surfaces not true or rough. Shaft bushings may have too much wear letting the gear teeth contract the center sections of the pump. The other possibility is the seals be damaged when installed. There may be pressure spikes in the system. Old dirty oil in the system.