Having issues with stick cycle times in and bucket curling in on a 330B 6DR prefix Checked pilot pressure Checked RPM speed sensor throw service menu Checked each pump individually (swing stall /each track) both are reaching 5000psi Pilot pressure good 600psi Pilot shuttle is below 200 psi when stoking pumps Both pumps stroke up to 5000 psi when boom is held over relief Checked speed times for tracks stick boom Stick in is almost 5.38 seconds Bucket in or curl in is 6.68 seconds curl out is 3.8 seconds Changed the pattern valve to cat controls did not change stick speed was thinking pilot valve on joystick issue Engine is reaching full RPM speeds are at 10 pressure checks are at 3-4 on the speed dial PRV is reading in service mode. And to spec as well Cylinders don’t drift or settle (no squeaking Filters and oil have been changed well kept machine and cat lubricant additive has been put in tank few times. Cut filters nothing in them Any thoughts beside flow testing No weird noises from pumps no leaks And good power just slow if I go To load a truck etc swing is fine and travel is fine tracks straight boom is fine. Stick out is fine bucket out is fine
How long has this been going on? Did it just start? Any work done recently. Must be cold where you’re at. Possible that cold Hydraulic fluid, not helping. Does it get better or worse or stay the same after warming up? Check lines, cylinders and pumps for excessive heat, compared to everything else. Sounds like a restriction somewhere.
Hello sorry for late reply 7 seconds for bucket curl in time or (cylinder extend/out ) which is on the high end of cats cycle time , I’ve checked pump pressures , and cycled both pumps by stalling swing , stalling tracks out all pressures get up to 5000psi on engine speed 3 that’s with machine warm Tracks rotate at same speed. Pilot pressure is perfect , engine rpm/ speed sensor is working No cylinders drop or creep down So squeaking in cylinders My pressure tests rule out main relief but Im curious if pulling out stick circuit relief or bucket relief checking them and or turning them up No banging or hammering near pumps all clamps are tight no air leaks , Hyd fluid is good , filters are new , cat hyd additive x2 added when serviced New fuel filters and checked tank / ensured engine was getting to full rpm and reading , to stroke pumps out so it doesn’t default Check pilot psi, 575-600. Main relief, boom raise speed dial 3-4, should be close to 5000. Power shift should be low in stall 180-230psi or the engine is weak/flywheel speed sensor issue Checked that as well The extend retract times are close to serviceable but at full rpm I feel the bucket or stick in should be a touch faster for loading trucks in KW+ and in dig it’s slow and I feel I’m waiting for the machine to catch up all the time. Or I have to show up for the stick to raise to get up over the side of the truck when loading We have multiple deere excavators and I know they aren’t completely the same as a cat for cycle times , I’ve run a few cat Hoes but for some reason I’m not convinced it’s right Swing , boom up , tracks all work well no slow issue's stick out is fine , curl out on bucket is good but stick in or bucket in slow
Flip my numbers they are wrote down opposite, whoops lol
Read your whole description above. Could you have some binding happening in the pin between the stick and boom. Could a hose have been changed that has a smaller inside diameter or a restricted fitting on the hose which would not affect pressure, but would affect speed. Simon C
Pull the stick and bucket control spool assemblies & Inspect for: Scoring, scratches, or rough machining on the spool lands Burrs or contamination in the bore Corrosion or varnish deposits (common in older machines or with old fluid) Verify spool moves freely by hand without binding --- Your pump shuttle pressure (below 200 psi during stroking) is good, but the load-sensing margin on the stick/bucket inlet valve maybe drifting: The LS compensator on the main pump may not be responding equally to all load-sensing signals If the stick LS signal line has a restriction (kinked hose, partially blocked shuttle), the pump's margin calculation fails, reducing flow to that circuit Verify LS line pressures: Measure pump discharge pressure minus stick circuit load pressure during stick-in extension (Should be approximately 25-30 psi margin) Compare to swing LS margin (which works fine) If stick LS margin is significantly higher, the compensator isn't properly tracking. (LS pressure should be load pressure + ~25-30 psi) --- Even though you changed the pattern valve, the proportional control electronics could be degrading: Insufficient dither signal to the stick proportional valve solenoid Valve driver card on the CAN module providing weak command signal Joystick potentiometer drift specific to stick-extend position In service mode, verify: Stick proportional valve solenoid amperage during extend (should increase smoothly 0-10A) Monitor voltage output from joystick potentiometer for stick extend axis Confirm dither frequency and amplitude on oscilloscope (typically 50-100 Hz, 2-5V peak) Before committing to spool removal, perform the flow test. This takes 20 minutes and definitively proves whether the problem is in the pump (already ruled out) or the control circuit. If measured flow during stick-in extension is significantly below CAT's specification sheet, you know spool/relief work is justified.
its not pressure but flow that increases or decreases cycl times, how much oil going in the cylinders