Hello all, I've been posting a lot about the case 9020B lately but I wanted to make a new post on the track problem. I changed the final drive oil and looked at the planetary gear inside and it looks great. Put oil back in and moved the track a little to move the oil around. Track still does the same thing, acting like it doesn't have enough power to move it. I was messing around and whenever I use a different hydraulic function it works great! I hold the bucket lever down then use both track levers and the left track will move with the right track perfectly. What does that mean? Anyone seen that? I can't get the guages till Friday so I'm just messing around seeing what I can figure out. Thanks, Brendon
It usually means that there is a problem in one pump function. When you operate something that requires two pump function both pump flows are joined together and now your travel works. It's been too long ago that I did any work on those so don't remember the specifics of how that system is supposed to work. If you had a hydraulic schematic that I could study, I could probably narrow down the areas that could be a problem.
I do have a hydraulic schematic. Give me sometime to get it uploaded. Thanks for your time!
Worn seals in the centre/swivel joint can cause the same symptoms. By operating another function allows more oil to flow threw the joint and makes the track rotate.
Oil through the swivel would have to go somewhere else at the same time with two pump flow. That theory is plausible but how would you confirm it? Since the case drain line is usually a #4 or possibly a #6, a case drain test at the swivel side of the motor might show that. If it is leaking into the other motor though the opposite track would creep when only operating the slow motor.
I would think you have obstructed servo to that travel pedal. But first and foremost, have you measured track sag? Are they tight like banjo strings? Read your ops manual, measure sag, loosen or tighten as needed. Make no hydraulic adjustments till you've performed this simple test. Now, let's assume you have good sag. Let's see if travel effort is hindered in forward, reverse or both. If it's both you have obstructed oil to foot pedal. If its fwd or rvrs its return servo to spool. The reason it straightens out with boom or dipper is because they need 2 pump flow. That automatically strokes up both pumps. Then your travel is corrected. No, I dont think you have a pump or motor issue strictly on what you've shared so far. I think you have a filter fitting that's jammed up with junk.
Check pressure on P2 pump using bucket or boom. Question though when you bottom out bucket and track works does track still work when you release bucket?
Hey everybody sorry I've been away for a while dad has had some bad health issues. Wanted to give you guys an update. The hydraulic pump blew on the excavator yesterday. Well I'm pretty sure. There are metal shavings all over after I drained the oil. Here is a picture. Taking the pump off tonight. Should I have it rebuilt or buy a new one? How do I get all the metal shavings out of the system? Does the 9020b only have e one hydraulic pump? (I'm pretty sure it does) any advice yall have I would appreciate greatly.
2 pumps by the look of it and rebuild/replace both pumps. I have seem tight fisted owners replace only 1 pump and after a few hours work the other one buggers up. The machine will require a full system clean
You wont get all of the metal out of your hydraulic system without a complete teardown of EVERYTHING. I hate those contamination failures...……..they can be nightmares. The best you can do without spending a fortune is to clean out that hydraulic tank and the suction lines. I have gotten super lucky in the past on a few like this as most of the contaminants were in the loop. It really depends on how much you want to spend VRS. what the machine is worth overall. Best of luck...….I feel for you.
The stuff in the bottom of the tank looks like brass. That would indicate broken slipper feet. Was there a lot of noise coming out of the pump? If that is the case you will need new rotating groups which in most cases makes it cost prohibitive to repair the pump. The usual repair when they shotgun is as Vetech63 states. Removal of all the hydraulic components, teardown, inspection and reassembly. The other side of this depends on your tolerance for risk. Install new pump, clean out the suctions, replace all the filters and clean as many screens as you can find and then run it for a bit changing filters every so many hours. I've been lucky on Komatsu excavators doing this but they generally flush the all the debris into the hydraulic tank where the suction strainer does a good job of keeping them from flushing through the pump again. Sumitomo units don't work the same way.
What does the return filter look like? Does it have a lot of metal in it also?