Hello everyone, I have a Cat 287B Serial Number CAT0287BCZSA01866 with 2700hrs track skid loader that is giving me some hydraulic problems. Here are its symptoms..... If I raise the lift arms all the way up, and then let off the joystick, the pump wants to keep pumping until i wiggle the joystick around to get it to stop. It doesn't grunt or make any weird noises going up what so ever. If I lower the arms back down to the ground, the moment I start going back down, the pump starts to grunt and bogs the motor way down, and will eventually kill the machine sometimes if i don't move the joystick around to free it up. So this is when it is returning fluid back into the tank... Also I can tilt the buck down with no problems until its all the way down, then the pump keeps pumping until I wiggle the joystick to get the pump to stop pumping. If I tilt the bucket back towards the lift arms, or back to its normal position, the pump starts to grunt and bogs the motor way down, and will eventually kill the machine sometimes if I don't move the joystick around to free it up. This would also be when fluid is being pushed back into the tank.... All the steering and driving hydraulics work just fine as they should, its only in the bucket and arm controls. I have replaced Part #278-8718 which is called a GP-Pump Control Valve, and this made the problem worse. when I originally was having the issue, i took this valve off and cleaned it, put it back on, and it helped a little, but didn't solve anything, But it differed the symptoms so I assumed this maybe my problem. Now that it hasn't, I spent $495 on a valve for no reason that I can't return. Any help here would be greatly appreciated as I am completely stumped, and if I can't get it fixed I am going to have to take it to CAT and have them fix it which will cost a ton. Thanks, Tate 605-359-2900 ALSO- This Hydraulic light is on in my cab?
That light is for the hydraulic system interlock override. The Operation Manual says this about it ......... Interlock Override - The interlock override allows the auxiliary hydraulic circuits to function with the armrest in the RAISED position. First activate the continuous flow control that is located on the left side joystick. Press the bottom of the interlock override switch. This will activate the interlock override function. In order to turn off the interlock override and continuous flow, press the bottom of the switch again. NOTICE - Do not leave the machine unattended while you have the interlock override function activated. The switch the manual refers to is same one as the hydraulic lockout switch. It's the 3rd of 4 switches mounted up in the top RH side of the cab, just out of shot in the RH side of your photo. Try deactivating the interlock override and see what happens.
I tried to get the light to shut off, but it will not... Would this be somthing monkeying with my hydraulic issue I'm having?
It could well be, but I'm out of ideas if pressing the lower half of the lockout switch will not deactivate the interlock override. As an idea, try activating the override again. I know that according to the light it's already activated, but try it again, then try deactivating. To activate the interlock override you must first activate the continuous flow control on the LH joystick.
I also have this toggle switch at the far bottom underneath the Parking break button and have no idea what it is for? Does this turn on my high flow? I know the interock button is working (at least i think) because when I press it up it will turn on another light which is RED right next to the one I am trying to shut off....
I can't change the interlock switch by activating or deactivating it, the only thing that changes is if I press the top of the switch it turns on a RED light to the left of the Yellow light I am trying to turn off......
The switch is a rocker switch and serves 2 functions. Press the top half of the switch and it activates the hydraulic system lockout and lights up the red light you speak of. Press the top of the switch a 2nd time and it will deactivate the lockout. The interlock override is a bit different. First you have to get Continuous Flow, then you can activate or deactivate the interlock override by pressing the bottom half of the switch. To get Continuous Flow activated ......... Press one of the two auxiliary hydraulic switches that are located on the right side joystick. Press the continuous flow switch on the left hand joystick and release the continuous flow switch. Immediately release the auxiliary hydraulic switch after you release the continuous flow switch. The continuous flow function will be activated if the operator releases the auxiliary hydraulic switch within one second of releasing the continuous flow switch. Press on either the auxiliary hydraulic control or the continuous flow switch in order to stop the flow to the auxiliary circuit. The switch below your parking brake switch operates the Auxiliary Hydraulic function (but only if your machine is equipped with said function).
It could have the aux circuit staying engaged and stroking the pump. Try un plugging the bottom of your joystick. I never worked with the interlock override, so it could be a control issues as Nige has said as well.
It sounds like your pilot pressure controls under your joystick are sticking and not allowing pilot pressure to stop as it should. They are the silver looking buttons that press down as you manipulate the joystick. Undo your covers, and take a peek make sure they are not sticking in any way. Here are some pics of my CAT 287b.