200 h.p.d.i. high pressure pump..

My high pressure side only reaches 100 to 250 p.s.i. after replacing all filters..
1) Is there a rebuild kit??
2) If not, do I need to purchase the entire pump or just a certain part of it???
Any help will be greatly appreciated....
Thank you.....

[boats.net]

You need to remove and determine what is damaged. The valve is replaced as a complete unit but you can some parts for the camshaft assy, it's usually better to replace camshaft assy as an assemble.