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Construction Equipment Tech Hydraulics, Electronics, General Engineering, ect in constr equip |
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#1
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4200XL hydraulic issues
Hey everyone. I am having some trouble with the hydraulics on my excavator. It started acting up and I was pretty sure it was a faulty servo giving bad feedback. I figured it was the 2nd servo that is set to the ele channel because it only seemed to act up if I moved that function. So, I swapped the tower pro servo out for that channel with a hitec 5645mg.
I must note that first I was thinking that it was the servo that controls the valve(4th servo) because it was the only one I could see moving(before I figured out how to use the display setting on the tx). I removed the 4th servo first and replaced it with the hitec. That didn't solve my issue so then I realized it was the 2nd servo on the block that controls the function that was acting up and that I should have replaced that one. So after swapping the servos back out and putting the Hitec on channel 2(ele) and putting the original back on the valve(4th servo) my problems are worse. Now, it's almost as if the valve isn't working properly to let enough fluid get to the rams. None of the hydraulic functions work properly or at all. It will move very slowly if I push on the arms and hold the function in that direction. I have checked radio settings and all seem to be correct. I am going to drain the system and refill with fresh oil and see if that helps any but if that doesn't work I'm not sure what to do. Any Help is appreciated! |
#2
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Re: 4200XL hydraulic issues
Is your servo moving the valve too 100 percent? maybe check your settings to see if there are operating and moving them as far as they should be. Also I found mine was slow its the 2.0 version so no 4th valve I put 22 weight oil in it runs much faster with thinner oil. also check to see if any crap is plugging the system.
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#3
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Re: 4200XL hydraulic issues
When you changed servos, did you 1st center new servo before installing into valve?
__________________
Sharing knowledge is one thing that defies basic arithmetic logic --- the more you share, the more you get! Joe |
#4
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Re: 4200XL hydraulic issues
A point I have had to adjust some is the pump ESC. Check to see that the pump is running fast enough. Caution on not running it too fast though. I will try to look at mine today and see what my pump ESC is set to. How long have you had the machine? are you sure all air is out of system?
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#5
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Re: 4200XL hydraulic issues
I've checked radio settings and all seem to be correct. The servo is set to move 120%. I did center the servo up before installing into the valve. I put the set screw back facing down towards the hole in the bottom of the valve block just as the others are. I am going to try draining all of the fluid and refilling with fresh. I had been using 32 oil and it was working great before the servo issue. Or at least I'm guessing it was a servo, it could be the tx/rx giving me the issues. I also want to drain it because it is possible that I over filled the machine with oil.
Hopefully after work today I can get it going or at least narrow down my issue. |
#6
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Re: 4200XL hydraulic issues
Ok, so I drained the system and refilled with fresh 32 oil...but the issue is still there. It's as if not enough fluid is getting to the cylinders to move the rams. It will move a tiny bit(3-4mm) but has absolutely no power. But when I manually move the arms while holding the controls in that direction you can tell it wants to move the rams it just doesn't seem to have the force. I have ordered some 24 oil to try and see if that helps any. Any other ideas would be appreciated. Is there a good way to try and flush and trash from the system? I don't think that is my issue because I can see the fluid moving through the lines when I turn the pump on. However, I am willing to try anything at this point.
Also, the pressure relief valve in the line and the one on the tank...how should those be set or does it matter? |
#7
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Re: 4200XL hydraulic issues
did you remove the tank to clean it out.
I did that and had same problem as you, turns out tank needs to be put back the right way or you don't suck enough oil to move rams. |
#8
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Re: 4200XL hydraulic issues
I think it's a valve center issue that you have... if the 4th valve turned one or two splines when you changed out servo, that would throw off your mixing of it. How does the pump motor sound with pump on & no stick movement, does pump motor sound like it's laboring? Any change in motor speed/sound with stick movement of valve cyl servos?
You could either pull the 4th valve servo out & turn valve by hand to try to block the oil flow back to tank, then try your cyl movements. Or you could adjust center point in radio settings of 4th valve servo, all the way + or - while a valve/cyl servo is activated. You still have your external prv to prevent any line ruptures.
__________________
Sharing knowledge is one thing that defies basic arithmetic logic --- the more you share, the more you get! Joe |
#9
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Re: 4200XL hydraulic issues
I will try to adjust the valve by hand once I get off and see if that works. Hopefully, that is the issue and I can get it figured out. I read on an australian forum a guy was having similar issues and it turned out to be his tx. Maybe that's not the case here.
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#10
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Re: 4200XL hydraulic issues
what % is your pump motor running at? Does sound like a 4th valve issue but why not check. Also if this is a new machine to you the manual is a bit light on the oil required to fill the tank after cylinders have been moved. I added another 50ml + after I initially got things running. Saw some air in the lines and could hear it sucking for more fluid. It could be a mixing issue on the TX, I don't have the 4 valve block but think there is a thread on here about adjusting it. Mainly making sure your Aux 3 (F mode) is at the "N" position(not 100% on that) and possibly adjusting your pit trim knob.
Maybe this one? http://www.rctruckandconstruction.co...ghlight=4200xl Last edited by TheBennyB; 12-14-2016 at 12:12 AM. |
#11
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Re: 4200XL hydraulic issues
I messed with the valve and moved it one or two splines towards being closed more. It seemed to help some and it started moving a little more. It still isn't where it was though. I'm thinking another spline or two will help more. I also received my 24 wt oil to replace to 32wt with. Hopefully, that will help some too. I am going to try it today after work.
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#12
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Re: 4200XL hydraulic issues
So, I replaced the oil with Mobil 24. That did not solve my issue. The pump motor seemed to strain a bit more. It does sound like there is load on the pump motor when operating functions. Everything is just very slow and almost doesn't move at all. I am pretty sure it is a 4th valve issue and that the valve isn't closing as it should when the others are opened....but getting it lined back up in the correct spot is a challenge. If you move it too far, it closes the valve all the way and the motor shakes and I immediately turned loose of the control. I cant seem to find that sweet spot. Also, I have checked the 3 way switch on the controller and it is all correct. The wheel above the left joystick on the controller seems to have no effect on my model...not sure if it is supposed to.
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#13
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Re: 4200XL hydraulic issues
Quote:
Quote:
You have to look at the "ISO VG" (weight/thickness) on their website here: https://www.mobil.com/en/industrial/...s/mobil-dte-22 Also keep in mind, RC4wd recommends to use Mobil DTE 22 which ironically is the ONLY one that matches with ISO VG 22 weight just to complicate things more. Have you figured out your issue yet? Wow I just realized the last post was exactly 1 year ago. Last edited by liftmys10; 12-12-2017 at 10:54 AM. |
#14
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Re: 4200XL hydraulic issues
You mentioned that you replaced the tower pro Servo with a Hitec Servo, did you go into your Tx menu and reverse the function of the Servo. I replace all of my servos to Hitec and they run reverse to the tower pro ones. Also I adjusted my end points to 100% on all of my servo channels. Found out that with the end points set at 120%, I was burning up the tower pro servos. They were over heating because they were bottomed out every time I would open the valve. Reduced the end point and check to see that you have good movement of you cylinders. Hope this helps. Keep us posted.
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#15
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Re: 4200XL hydraulic issues
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Have a new 4200xl, about a week old and the channel 2 servo is dead. What a bummer. Wondering if you guys would be so kind to tell me which HiTec servo you used to replace the stock servos? Hoping the spline is the same as what they have in this machine. Also, how was taking them out and replacing them? |
#16
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Re: 4200XL hydraulic issues
I haven't had any luck resolving the issue yet. My kid was born and has been killing my piddle time haha. I hope to get the 4200 out soon and continue working on it. What are y'all's thoughts on swapping to the 3 servo valve setup that comes on the newer models? I'm just not sure what could possibly be wrong with this one unless it's a tx issue.
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#17
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Re: 4200XL hydraulic issues
The verdict was an incorrectly assembled pressure relief valve....apparently I had messed with it and not put it back correctly. She's up and running again after about 5 years on the shelf.
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#18
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Re: 4200XL hydraulic issues
LOL better late than never... how did you figure out it was the relief valve
Never mind I just read your other post.....sometimes you just have to step away from a problem.... maybe not a 3 year step but .....Glad it's working again. Last edited by jerry56; 09-05-2021 at 03:23 PM. |
#19
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Re: 4200XL hydraulic issues
Nice, picked up a 4200 second hand and have been slowly diagnosing issue after issue, it's almost there but I'm getting a lot of air in my line with similar results. I did have my pressure relieve valve fly across the room with some oil behind it, I'll double check how it's in there, probably going to tear it apart and redo all the seals, double check the servo adjustments and go from there, thanks all!
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