CASE 9020B

[Coy Lancaster]

If you check pressure with track blocked and pressure is low and then cap off lines at motor first and retest. You will find out if problem works s in motor. If pressure is same the cap lines above swivel which will eleminate the swivel, if pressure is at main relief then you know swivel for is the problem if not then you need to look else where. I did have a machine wit a bad pump regulator once that acted just like this.

 

[Ronsii]

This is where you could switch lines around before or after the swivel and get some ideas of what problems follow what lines.

 

[John C.]

Checking the case drain on the motors is the usual first step to troubleshooting a travel problem. Lock up the track, remove the case drain hose and direct the flow into a container and energize the track. Shouldn't be but a few drops of oil from the drain if the motor is good. A bad motor will squirt oil instantly.

Leaking swivels usually show up when a track is slow in one direction only or when you see creep in the other track when trying to turn. It may also manifest with high case drain if a seal on ether end is leaking by. The sure way to find it is to cap off the suspected leaker and open the port next to it. When you pressurize the suspected port you will end up with oil out the open port. In most cases it is easier and cheaper to just pull the swivel apart and reseal it.

The problem I've seen plenty of times with weak travel has to do with the pumps. The regulators are for the most part just springs working against a reference pressure to control output. Metal fatigues, meaning the springs loose some tension and the pump doesn't put out like it used to. Usually a flow meter would be used to see that but many times you can adjust the weak regulator enough to make up for the drifting travel. But if a pump is weak enough to cause a travel drift problem it would usually also show up in other functions. Cycle times would be a little slow on boom up or arm out. The problem with messing with the regulators is that you have to know what is going on in the regulator and pump or you can screw up the performance in the whole machine.

 

[td15c]

Brandon I have a old 2700q they are supposed to be the same as the 9020b accept for the motor. if that is true then you have fuse for your safety lock out, and a relay. Also if your lock out button is on it will stay on even with the lockout lever forword.

 

[td15c]

If you want to bypass the lockout so you can move the machine . Unplug the solenoid in the pic whith the red probe pointing at it . Jump 24 to the red wire and ground the blue that should bypass your safety lock out. That solenoid block is in the door with the hydraulic pump mounted on the front wall.

 

[Brendon Benton]

If you want to bypass the lockout so you can move the machine . Unplug the solenoid in the pic whith the red probe pointing at it . Jump 24 to the red wire and ground the blue that should bypass your safety lock out. That solenoid block is in the door with the hydraulic pump mounted on the front wall.View attachment 189208 View attachment 189209

Awesome thanks man I appreciate it. That look exactly like my 9020b. I'll let you know if it works out. Would you happen to know of there is anyway I could get the factory drawings? Just in the future when I want to fix it for reals.

 

[Brendon Benton]

Checking the case drain on the motors is the usual first step to troubleshooting a travel problem. Lock up the track, remove the case drain hose and direct the flow into a container and energize the track. Shouldn't be but a few drops of oil from the drain if the motor is good. A bad motor will squirt oil instantly.

Leaking swivels usually show up when a track is slow in one direction only or when you see creep in the other track when trying to turn. It may also manifest with high case drain if a seal on ether end is leaking by. The sure way to find it is to cap off the suspected leaker and open the port next to it. When you pressurize the suspected port you will end up with oil out the open port. In most cases it is easier and cheaper to just pull the swivel apart and reseal it.

The problem I've seen plenty of times with weak travel has to do with the pumps. The regulators are for the most part just springs working against a reference pressure to control output. Metal fatigues, meaning the springs loose some tension and the pump doesn't put out like it used to. Usually a flow meter would be used to see that but many times you can adjust the weak regulator enough to make up for the drifting travel. But if a pump is weak enough to cause a travel drift problem it would usually also show up in other functions. Cycle times would be a little slow on boom up or arm out. The problem with messing with the regulators is that you have to know what is going on in the regulator and pump or you can screw up the performance in the whole machine.

 

[Brendon Benton]

Thanks for the reply that gives me a lot better understanding. All hydraulics work good except for that left track. It's both directions unfortunately. I can get it to move very slow if I move it just right. But that's just because the other track is doing all the work.

 

[Coy Lancaster]

One other thing that should be considered is the drive coupler in the planetary of the final drive. If it's stripped it could cause your problem also.

 

[Brendon Benton]

One other thing that should be considered is the drive coupler in the planetary of the final drive. If it's stripped it could cause your problem also.

Well I was able to work on the excavator again today. I pulled the planetary gear out and it looks good. It's got to be hydraulics. A buddy is going to let me use his gauges so I'll see what I can find out.

 

[Brendon Benton]

If you want to bypass the lockout so you can move the machine . Unplug the solenoid in the pic whith the red probe pointing at it . Jump 24 to the red wire and ground the blue that should bypass your safety lock out. That solenoid block is in the door with the hydraulic pump mounted on the front wall.View attachment 189208 View attachment 189209

Thanks for the info man. I was able to get the factory prints on it. It was two things. My wiring was backwards. There 2 wires the same color so I swapped them and it had power. Then I found out the relay behind the seat was also bad. But the control lock button work now and I can move the machine.

 

[Brendon Benton]

Wish I could post this video but the file is too big. It's a video of me getting the left track off the ground. It will move but slow as hell. Won't move with weight on it. I'm getting some hydraulic guages from a friend so hopefully I can have it traced soon.