Hello Guys I come to you fro help. We have this excavator and everything else works fine. But Boom raising is slow. Hose is fine, so can you help me in pointing what electronic device we can check? Please?
Hi. I had the same problem with some 228-3s. It was the sensor on the boom that tells the machine when the boom is almost up. When the boom gets close to the top the sensor slows the boom down so it doesn't slam. I believe the sensor is mounted by the right side boom pin.
Coming back with this. It doesnt have a sensor at the boom. The weird thing is that today it started to work fine. After 2 hours the problem showed up again. I think it might be related to something getting too warm
Hey Movindirt, do you mean the junction box close to the main valve? Where 8 hoses and 8 sensor are found?
I'm pretty sure that sensor is the problem. The 228s would work fine then all of a sudden slow boom. Does the boom go down slow too or just up? If its slow both ways it might be a valve problem. If its just slow up then its prolly the sensor. It's not by the valve block. It should be right at the boom foot, it's just a small magnetic sensor. The boom will be right next to it when it's all the way up. That is where it is on the 228s anyway, the newer ones may be different.
No, It doesn't have that sensor at the bottom pin.
What I did was replacing the sensor for boom raising for another one (joystick hoses get to the junction box located behind main valve, so you have the 8 hoses and 8 sensors. So when moving joystick it sends oil pressure to the box, sensor notices that and transmit to the pump controller. More pressure more volts) but the problem persisted. What I noticed is if you wait like 10 minutes, boom raising works fine, but after that problem resumes. So I will change oil and filter and see what happens
Back again. Operator mentions that he has to push all the way the joystick in order to raise boom and it starts to do it slowly. Does this right joystick might have some kind of pressure switch for raising/lowering boom?
I would guess that you have a hydraulic problem and not an electrical issue. Possible problems include the safety suction valve or a pressure compensator valve. Either one being stuck open would allow supply oil to go back to tank instead of feeding into the boom cylinders.
Did you have the anti-drift valve on the system. if so I will start to see if the relief really seat weel on the seat. if the drift feature let some oil to flow it will send boom cylinder piston side oil to the tank while actuating the boom joystick. When you close the stick (stick in) can you saw another action moving (making stick in untill relief open multiple times) of course at warm oil temp. if another action is moving (even a little) you have some bad compensator seals.
I found the problem. I took the raising and lowering boom hoses out. Then tried with a wire to check the holes and were fine at both sides, Then I saw this compressed air and tried it. Right away I noticed the air coming out was poor in both hoses. In short, both hoses collapse at the middle. Changed both hoses (begin careful when making the hoses, not tightening too much or you'll have oil restriction). And now machine is working fine.
Dog gone! you can't even trust hoses these days. Were they externally damaged as cause? good job finding!
The pressure switchs at the junction box are there to tell the engine controller to raise rpm's...they do do control speed of any controls.......HOSES ARE THE MOST LIKELY CULPRET AT THIS TIME....
In fact, hoses looked great, the two were the best looking hoses. Thanks Mr Komatsu for the tip. So if I'm raising the boom and engine keeps same rpm that means the pressure switch fail?
Yes, best way to check is set on auto-decel......hit function and rpm's shoul increase. If not then switch failure......caps lock stuck sorry for yellin......