Hi everyone, I have a problem with a caterpillar wheel loader 962g (3bs). I had a broken implement pump and after installing a new one, I have a time delay with 3-4 seconds when I try the lift raise & tilt back functions. I connected to Electronic Technician and I saw the solenoids which energizes immediately after moving the lever back. Also I measured the pressure to the pressure tap of these functions, and during the time delay (3-4 seconds) there was no pressure. After 3-4 seconds, pressure comes and bucket start lifting normally. I am confuse now, what could be the problem . Can anyone give me an idea? Thank you! :notworthy
If you have access to ET then try calibrating all the solenoids for the lift and tilt function.
Hi Nige, thanks for the reply. I did all the solenoid calibrations, but still the same thing happens. Lift raise and tilt back activate only after 3 seconds after moving each respective lever. Pilot pressure reducing valve is set to 34.5 bar as in the manual. At the Raise pressure tap (2) (attached picture) I measure the pressure and instantly after moving the raise lever current goes to the raise solenoid (seen at ET), but pressure does't. Max pressure 18.2 bar comes only 3 seconds after holding the lever in the raise position. The same thing happens to the Tilt back function, max pressure 18 bar comes with a time delay of 3 sec. , but solenoid current comes immediately.
The solenoid valves become magnetic when energized and therefore attract metal filings. I have seen after a failure in the hydraulic system where the valves will become contaminated and not work properly. It's hard to believe they would all fail at once but it's just a possibility. The other thought is that maybe there is something blocking the pilot supply porting to these solenoid valves. Is it possible the pilot lockout valve is not opening completely due to contamination.
Hello everyone, We are expecting problems with the hydraulic Vane pump of a CAT wheel loader. We have changed it for two times about every 1000 working hours (from the last change) because it has structural damage mainly in the rotor and port place seizures. Pump number is 146-5076 and serial number of the truck is 3BS00338 of Caterpillar 962G. Can anyone please help in determining what can be the problem that damages this pump. Pump has been changed from Caterpillar official dealer with original parts? Thanks in advance