Recently purchased a 2018 Komatsu D61PX. Blade functions are slow and sometimes no movement at all. Things I have done to make it cycle faster for a few minutes but they goes back to slow or no movement. 1. Cycle implement lever. 2. Removed 1 steel mesh plug filter at control valve. Still does the same. I have checked HST pilot pressure through monitor and found pilot charge pressure to be within specs. Fan motor does seem to be operating at high speed therefore maybe robbing all the pilot pressure to the comtrol valve. One weird phenomenon is that when I look at the hydraulic schematic is that the ripper control seems to get the pilot pressure right before it goes into the control valve. This dozer don’t have a ripper but does have the control lever and the lines are capped. During the slow to no blade operation the ripper operation seems fine, meaning if I cycle the ripper lever it receives enough pilot pressure to dead head the system and builds pressure to spec. Any one out there with knowledge on this issue?
The Komatsu D61PX series has several versions, from D61PX-12 to D61PX-24E0. Which version is your machine?
It’s the D61PX-24
@LACHAU Please share schematic
This is the link to download: D61EX(PX)-24 SEN06577-06 (05-2019) SHOP MANUAL MediaFire is a simple to use free service that lets you put all your photos, documents, music, and video in a single place so you can access them anywhere and share them everywhere. www.mediafire.com Good luck.
The blade movements, including raising, lowering, tilting, and rotating, are controlled by linear solenoid valves that Komatsu calls EPC valves. However, the ripper unit is controlled directly by the hydraulic system via a control lever. Therefore, you need to check the electrical control system for the blade movements.