Cat D5H xl series 2 slow blade lift

[catman13]

I have a d5h xl with a 6 way blade( serial # 8rj04559 ) the blade is getting real slow to lift, I adjusted the linkage did not help , the ripper / angle / tilt seem work fine , found that when I lift and tilt at the same time it seems to work a lot better but hard to grade doing this .
I was wondering where should I start looking, and where do I attach a gauge to check pressure, any help would be

thanks

 

[sled dog]

Catman, don't know if it will help but worked on one of those a decade ago, same problem. Gauges in lift lines would fall, then rise when you hit end of stroke. Unhooked one cylinder at a time from blade and capped its hoses. One worked fine with full pressure, one had blowed piston seals and blade wouldn't lift and had low, low pressure. Bypassing internally.

 

[dozr]

there is a resolver valve in lift control valve, part no. 4t4525 on page 7 here there is a thead about hot hyds and alaskaforby4 put a control valve brake down on it. my 5h has done same thing, you could get to it easy if there was not a flat plate behind valve, but because of it you have to brake it a part next to last section toward center. that was just like mine acted. my serial is 3md442.

 

[dozr]

forgot to say there is a clear o ring on it you will find that blew.