What would cause weak track movement on my PC50. It sucks at turning, and it just dosen't like going up small hills. Could my travel motors be worn out? What is there to ckeck? Thanks
Always first check that there is nothing obstructing full travel of drive levers. If the drive levers are Ok, and all the other functions work properly except drive, a very common cause of this is failed seals in the rotary swivel in the center of the machine, but there's no real effective way to test it. You could test your drive motors. Each motor will have three hoses going to it, two large ones, and one small one, the small one is the case drain line. Disconnect the small hose connected to a motor, plug the hose fitting with proper threaded plug. Raise the track off the ground with the bucket so you can rotate track. A good motor will have minimal leakage from the case drain fitting on the motor while operating track. If you have more than maybe 1/2 - 1 gal per minute leaking from case drain, motor is possibly bad. If both motors test acceptable, your problem is likely the rotary swivel.
Are you lifting the tracks while rotating, counter-rotating the tracks while spinning the house with the bucket to turn? If you are just trying to turn while in the mud the drives just don't like it.
Thanks for the great info, ill need to check but with it being 2 speed is there anything different? yes its mostly wet dirt and can be a few inches deep
What do you mean spinning the house with the bucket?
As usual I didn't explain myself very well. What I mean is you would have the bucket in front of you at about 45 degrees facing the way you want to go. You would lift the tracks with the bucket than reverse the track nearest the direction you are going, forward the other track at the same time. While the bucket is still on the ground move the control to make the bucket, arm and boom go the opposite way of the turn. It takes a little practise but once you get it, it is a lot less stress on the drives. You have to do all three things at the same time or it will not work properly. Next time you want something to do with your machine go out and practise turning both ways. Everyone will wonder what you are doing going around in circles :beatsme but who cares. Just take notice that you can only turn so far without repositioning the bucket.
Thank you for taking the time to explain, i'll practice that for a bit lol
As for your question regarding the two speed tracking!! - as you are well aware when in high speed the machine will barely if at all want to turn unless you drop down to the 'lower' range. The hose setup on the track motors should be the same as previously described as activating the two speed tracking only increases the amount of oil flowing through the pipe to the motor. It could be that your motors are knackered (especially if previous owners tried to turn alot whilst having the 2nd speed engaged) or a possibly but not very likely that your tracks are too tight.
I've always use low range for turning, but i don't know very much history.
If you are sitting on a flat, level, smooth surface, can you engage one track and make the machine turn? It should be able to. Or does the track just stall out?
well i haven't got it off my practice area yet lol, where its loose wet soil. it dosen't stall out it, it just won't move
Sounds like you need to spend a little more time with the machine to get a feel of it's character. Not sure what you mean "it doesn't stall out, it just won't move". Isn't that stalled? nobull1 suggested using the house to help turn the machine, which is a fine way to turn an excavator if you need to make very tight radius turns. But any ex should be able to turn the machine on flat/smooth surface by using only one track and that track should not stall out while doing this. If it stalls, I'm suspicious of the drives.
I meant the engine never stalled down, but the track wouldn't move.
That's what I was referring to, stalled track. If your sitting on flat/smooth ground, engage one of the drive levers fully to turn the machine, and the track just stalls, I suspect drive problem.
Is this likely to be a serious drive motor problem?
I have a friend down the road from me that has a 12 ton older cat excavator. He lost most of the power in one of his drives and we were thinking the worst. In the end it was a worn piece that the lever pushes on that was worn. It was not letting the drive have the maximum amount of fluid. Once that was fixed it worked just as new. If you think you might have drive issues it might be a place to start.
That makes sence, if the lever is worn, i'll need to check that. Thanks
I would cautiously say no, as the chances of both motors failing at the same time is slim. If the symptom was that the machine turns well one way but not the other then I would look at motors. It may be time to get it checked in a workshop, they should be able to hook up a pressure meter to the drive hose and see how much pressure is getting to the motors, I don't think it is flow rate as that determines how fast the motors turn, or in other words if the motors have plenty of power but just move slowly then it is flow rate. My dingo had a problem with not enough grunt going to the wheels and I got it serviced (well it needed a new hydarulic pump due to the front seal leaking) and as part of a major service the hydraulic pressure is checked as well as the operation of the relief valve. It may be that your relief valve is opening too soon and may need adjustment.
Your right about the flow rate and speed. After thinking about what you wrote, my buddies machine had the motors running at different speeds, which made one side appear weak. Although the lack of flow did have an impact on the power as well, just not the same percentage decrease in power as it was in speed though. I agree two drives doing the same thing at once does not sound like a drive problem. I think if lifting the tracks and turning the machine with the bucket works fine and has enough power to get up hills I might just check the pressures as said and if the relief setting is fine use it as is. If the pump is weak but working it might last for a long time and not cost you any money.
If the pump is weak then you would have digging issues as well. If the machine digs well but has an issue with the track drive motors I would not look at the hydraulic pump being the problem. However this depend on the design of the machine, if it has a separate pump for the track drive then it may be a pump issue. This is basically a trace the hydraulic lines thing to see how the machine works. Most excavators have a 2 in 1 hydraulic pump, being main and auxiliary circuits, the track drive works off the main circuit as ex designers do not see the need for a machine to have digging power whilst traveling but may need digging power whilst using the aux circuit, such as using a hammer. How many lines are going to your drive motors? My Kub has 4 each for high and low, with 2 big hoses for high speed (more flow less pressure) and 2 small hoses (less flow more pressure).
I have no problem digging, how can i test pressures and flows, i cant see any leaks
i know to many on here this may be extremely obvious but are your tracks clean of rock, dirt and debris when you are having this problem?
You need a pressure and flow meter, this video shows them being used to test pressures on a Dingo/Kanga http://www.dingo.com.au/dingo-kanga.php The track drive circuit uses independent relief valves that are set lower than the digging circuit, this is a safety thing to stop you busting tracks if a rock gets caught in there, that's why it is important to get the right setting on the relief valve.
I don't want to rain on anyone's parade but excavator track circuits are always set higher than all the other circuits in the machine. To test the pressure on that machine you should look for some either square headed pipe plugs in the blocks on the pumps or they will be 17MM hex plugs that are O ring fittings. They would also be somewhere close to the pumps. Either on a block directly connecting to the pump or in a steel line coming from the pumps. To test the flow the easy way you just pick up the track by pushing down with the boom. Mark a spot on the track with paint or something that is easy to see. Rotate the track with the engine at high idle and the track in the high speed mode. Using a stop watch time how fast the track makes three revolutions. Make sure you run one revolution before starting the stop watch. Now turn the track the opposite way and run the timing test again. Once you have those times, run the test on the other track. There are specifications for how fast they are supposed to turn and you should be able to get that from your dealer. Usually if you have a pump problem it will show up here. Motor problems usually show up with tramp metal in the pump suction strainer or high case drain flows. Many times a swivel problem will show up traveling on one direction and not in the other. They might also show up with one track slow going one direction but the other track slow when you reverse. I've also had it happen that the problem came and went as I was swinging the house. When you run all these tests, be sure and write down all the results on paper and then review those readings when all are done. My memory isn't very long so I tend to forget what I saw. On paper you can usually see what is happening. Good Luck!
Are you sure it's not stuck in high speed? I had a rental KX-121 that acted like that. Turned out it was a piece of dirt or something that had the high speed peddle tripped. My trying to switch it in and out of high speed didn't work, it was stuck until I finally got it cleared out Ken
i still have both speeds no doubt