hydraulic pressure

[craigb]

I recently fabricated a backhoe for my tractor and was disappointed with the lack of digging power. I hooked a PSI gage up to a line from my loader valve and found I only have 1000 PSI at 1600-1700 rpm. When I increase rpm to 2400 rpm I get about 2100 PSI. I was always under the impression that PSI was constant and only flow increased with RPM. I was hoping that I did not have to sit all day with the tractor running at max rpm while operating the backhoe. The tractor is a case 50 hp diesel with open hydraulics. I am powering the backhoe through the loader valve power beyond fitting and it does have digging power with the higher RPM. I am toying with the idea of pulling out the tractor internal hyd pump to check its condition but thought someone might have another idea before I went to all that trouble. Hydraulic problems usually confuse me with very little trouble. Thanks

 

[Anonymous Poster]

Running the engine up to full governd [sp] speed is proper method . I believe you can actually damage your pump operating at low rpm. Family member is in excavation business and everything from Kubota compact to Kubelco track mount is always run full throttle. Dave