hello I'm new to the forum so any help would be appreciated. My uncle has a ex300-3c that has a slow left track until you use other functions then speeds up to normal, also the swing is slow until the machine gets hot then works fine. We just put new rear pump in and the front was changed last year and this machine only has little over 7000hours. this is mfg# 15M-11292 Please help almost $15,000 and same problems
have you had the pilot pressure checked?
you mean right at the pilot pump? what should pressure be? Why would other controls like bucket/boom be unaffected?
Without gauges to test pressures, i would look at the check valves in the front (Facing Forward) of the valve bank. I think they are Allen head plugs. With one main relief you have a check valve from each side so that if you are using only one pump the oil pressure will build up and push the check valve closed from the pump not being used therefore not allowing the oil to escape back to tank. It is not uncommon on that machine to have the check valve damaged. Left track and swing are off the same pump. If it is one of the check valves then your swing should be slow hot or cold if only using that function. While you are at it take the 2" plug out of the top right forward of the valve bank. That is your Switch Valve or Flow combiner Valve or your Straight Travel Valve which ever you want to call it. I can almost guarantee that the seals and back up rings are gone on it.
we tested pressures yesterday. with tracks locked up we got 4200psi on both pumps, 300 on front flow sense and 90 on rear flow sense until in p mode then came up to 300. also the pilot pressure was 800psi but it was before filter and not quite to temp. I pulled the relief on the left side of control valve because that is where the pilot comes into it for left track. I was thinking that the flow combiner may have something to do with it since bucket function works with travel through it. thank you for your reply I will try pulling combiner if I can find it. We had a guy from dryden in also who said that it may be between the halves of the control valve, there is check valves in there also, but only 7000hrs so how likely is that because it will be a pain to do all that without pressure test leading me there. Is there anything else I can pressure test while I still have the gauges? Thank you for your time.
OK we seem to be all over the place. First thing 4200 psi on travel is low. Should be over 5120 psi. Spec is 360 kgf/cm squared. You want to test on single functions only not combined. So in saying that, test left or right travel bucket or swing. Don't use boom or arm or two functions as the oil gets combined in the valve bank. If you test the functions I mentioned you will be testing one pump with the coresponding half of the valve bank as well as the signal to the pump. The poppet that goes in the middle of the valve bank is commonly the boom two check valve. What you get is very fast boom down when that happens. But there is also other ones in-between. Back to the start. You have to get your pressures up first. Block your track forward and reverse both sides to see if there is a difference. If there is not and you get 4200 psi on all. I would adjust the travel relief on the forward face of the valve bank. I would also put a gauge in the pilot line that goes to the main relief to make sure it is getting the signal when travelling. Once you get your pressures set then we can go after the slow track. Do a cycle time with the travel in the air, mark a track and full rpm P mode time 3 revolutions from a rolling start. Compare the 2 tracks. Let me know what you get. Even though I said the seals will be gone in the Travel Flow Combiner Valve. You do not normally get a travel problem symptom. What you get is the travel pressure sender over pressurized and it will not work and can leak. Also one of the two small pilot lines that go to the top right of the valve bank will blow/leak.
Do you have aux hyrdaulics, breaker or thumb? I had one slow track, slow swing, until I blocked the pilot line to the pedal (tee-ed from the track pedal) ex120-1, twin pumps
Okay I pulled combiner valve today and no o-rings or back-up rings on two spots from what parts book says, so the parts will hopefully be in tommorrow from thunder bay. How much of that is junk is likely to be stuck somewhere else in the system. What should the pressure be and where exactly to I tee into main relief and when traveling and should the track be turning? that will have to wait till tomorrow. Also there looks like there was a cyl on the arm at one time, I will ask the boss about that too. I will have more answers friday after work I hope because machine this machine has been like this for years. Thanks for all the help
The o-ring material will most likely have made its way to the filters. I never had anything stick because of the o-rings and back up rings missing off the Flow Combiner Valve. I carried a seal kit all the time and changed out the o-rings and the back up rings many many times with no operational complaints except that the auto idle wouldn't work at times. Tee into the main relief into the hose that goes to the top of the relief. I think it is a 1/4 jic but could be a 3/8 jic. Can't remember off the top of my head. Cycle time the track with it lifted in the air.
Will do the cycle time on track hopefully this morning, its saturday but this machine needs to get back to work to pay for unecessay pump. So it sounds like those missing rings aren't going to fix the track speed issue. I will maybe test the swing brake pressure while I am at it. Whats the odds the pumps aren't set up properly when rebuilt, they were done at reputable shop. I heard that they possibly need to be phased in to engine revs. Was talking to operator yesterday and he said there has been other issues as well with the boom and arm, but seems like everyone on it says something different, I never noticed any of that when I had it out in the yard other day but this has been going on a long time before I got there. One more thing is the bucket pressure on curl up was 3400psi when checked the other day seemed low as well. Will get back to you today and thanks for your time
First thing to do is get your pressures up to spec.
Just got back from shop and both tracks forward and reverse were all around 4200psi so I set them up to just over 5000psi, after I installed combination valve I did a cycle test on both tracks and got left 2:08 both directions right :25 both direction also no signal at all to high relief pilot. Also left track still runs normal when using other functions but slows by itself. What next?
did you check the aux pedal? you said you could see where old cylinder was fitted before on the stick When I had this issue moving the almost seized pedal back fully slowed things right down. So I'd rule out the pedal as it only takes minutes. one track, and swing were most effected. I blocked the pilot line below the pedals,I removed fitting, put a metal disk in there as a quick check. the line it was tee-ed off the track pedals, machine now is rapid
there was no cyl just solid thumb
i would do some further tests on pilot pressure. tee in at a few different points and compare, mainly right at the valve block. That way you know the signal is getting to the valve block, and you can look then to the high pressure system. Or swap the pilot line for the tracks and see if the fault shifts
Good idea to double-check the pilot pressure. Check the top of the valve bank left and right travel compared to what you have at the pilot filter. Easy to get to. See if there are is any difference. Is there any extra plumbing or valving that is not being used? Time cycles for the track is 27.3 seconds (Plus or minus 1 second) for three revolutions. Track in the air and running start. The pilot oil that goes and shifts the main relief valve gets its pressure from the travel spool blocking off the signal oil from going to tank. Does your auto idle work? Does travel kick up the RPM from auto idle? If so this is the same signal pressure that goes and shifts the main relief to block it out and allow pressure to build up to the travel relief pressure.
How does auto idle work? I don't beleive that idle came up when traveling but will double check that today. Is it possible I installed combo valve incorrectly since it still speeds up when using other function. I simply slipped everything in hole and put cap on, I never pushed anything hard enough to seat any orings inside. I hope not because I will have to drain oil again to rectify. Also I will test track pilot on top of control today. Not sure how many hours he will let me put on this machine. One more question where is travel relief I thought that was main high relief. So if pilot pressure is good at right/left travel then the problem is in control valve? Will it need to be removed and rebuilt if that is the case?
Auto idle works with pilot pressure fed into the valve bank through a fitting with a screen. From there it splits to 2 orifices to maintain pilot pressure before the orifices. One route of the oil goes through all spool functions except travel. The other route goes through the 2 travel functions, both in the neutral position go back to tank. When a spool is shifted even slightly the pilot oil is blocked from going to tank and pressure builds up and a pressure switch is activated. One for Upper functions other for travel. So if you have auto idle on and it has lowered the rpm, when you activate a spool the pressure switch sends a signal to the computer to rev up the rpm. When you travel only with both levers you get one pump to one side of the valve bank that feeds one travel motor. When you travel and activate an upper function, the upper function will activate the Switch Valve (Combo Valve). Now your front pump will feed your right travel and through the activated switch valve will feed the left travel. The rear pump is now available to the upper functions. So now one thing I need is the travel cycle times done as I mentioned above. Do it forward and reverse. High and low travel. Then take the pump control lines off the pump, plug the hoses, run a couple more hoses from the fittings into a bucket and try the travel. Main relief has the pilot line going to it on the top of the valve bank. The pilot line going to it is for blocking out the relief which is lower than travel relief pressure. That oil comes from the auto idle circuit i described for travel. The travel relief is on the front face of the valve bank. See pictures I sent.
I tested pilot pressures for left and right travel at control valve and they were both 650psi so normal. I also tested SA hose from solenoid 3 going to rotary manifold and got no pressure at all. Also now when in P mode the right travel kicked the revs down when engaged and went to left side when I switched right/left lines at control??? Should there not be pressure at SA port going to rotary when traveling?
SA will only get pressure when in high speed. You cannot get high speed with one track lifted in the air on that machine. To get high speed travel you have to have full travel pilot pressure on both travels. Measured from pressure switches under the cab. Then you have to have low pump pressure on both pumps. So let me get this. Only when in P mode the Right travel will kick the RPM down?? Not up??? Yet the left has no effect??? Until you swap the left and right pilot lines??? Where is the travel mode set at when doing this?? Low, Medium or High??
Okay now I understand the SA pressure. Not sure if it is only p mode that does it but when in p mode right track dropped revs to about e mode and yes problem does follow pilot when switched, and think it does this in all speeds. Sorry I never got a chance to do cycle time on tracks but did the other day right 0:25 left 2:08 Thanks for the help, will have to buy you some beer if we get it fixed
Rpm will drop if in slow travel mode. Here is the funny thing, when operating the travel lever left or right, as I explained before, the pilot signal oil gets blocked off and builds pressure and the travel pressure switch reads the signal to tell the PVC that travel has been operated. So in saying that it should not matter that you swapped the pilot lines as the signal is not from the pilot lines but from the spool blocking the signal line. As I understand the signal comes from the travel pressure switch on the valve bank. Just to prove that, swap the wires from the 2 travel pilot sensors under the cab and then try it again. Also on your time cycles, get a swing cycle time. 3 revolutions from a running start. This is the same pump as the left travel. Has there been any attachments or other valving put on this before? Any history on how this problem came up? All of a sudden? Was the valve bank ever repaired?? Did someone have to unstick a spool ever before? Did anyone ever have all the spools out? Please please please say no to the last one.
There has been problems with this machine along time. No other valving and beleive machine started with right track not wanting to stop turning thats why the front pump was changed and that didn't fix it, so I think uncle said it was a issue under cab floor sticking pilot or something. Then the left track started acting up but they've been working it anyway. The operator said if you lower revs it will start working again and then jack the R's up and it's good for a bit. And its only got 7000 hours so I don't thing anybody messed with control valve but can't be sure. As for the swing I will do cycle but it is slow until machine is warmed up. Is it possible the regulator on pump is not set up right.
Anything is possible with the problems you are describing. (Regulator) The lowering of the RPM then raising it and it works for a while, suggests to me port plate separation on the pump. You said they were new or rebuilt? The swing being slow until it warms, up then its good :Banghead got me on that one. Sure sounds like a combination of problems.
both pumps were rebuilt in thunder bay
I wasn't quite accurate when I told you that lowering rpm's would make it work right, it was actually changing work modes from m1 to m3 or 4 and when doing this the pressure increases on the line running from shuttle valve being fed and activated through solenoid valve #1 and stayed at 300psi for some time even when going back to M1. Where does neutral passage oil enter control valve and where does it exit and is this same circuit as auto idle and what should neutral oil pressure be. Also nobody can understand why switching pilot lines from left forward to right forward didn't switch track function accordingly. Which control lines should I be taking off at pump to check for oil flow and what should there be?
there's a lot of funny stuff going on. you mentioned a old issue track running on and not stopping and the pump was changed? was the sticking pedal valve repaired, I'd be checking for internal leakage within this pedal unit. i can't see either how swapping the lines hasn't shifted fuction. Is it possible that some pipes are not fitted in their correct location with all the works previously. I had an issue a long time ago and to rule out pumps I got an extension hose made up to swap the pump lines (main and displacement pilot line), I only needed extend the front as the rear pump reached the front pump. No difference so I knew both pumps were matched. You obviously have to swap electrical connectors etc..
Yes both pumps were changed on the advice of mechanic and hydraulic shop said they were both worn so don't know they didn't help anything. And found out last night he has owned this machine from brand new so nothing was really touched except pumps and cylinders. I think under cab was full of mud and ??? that got cleaned out and seemed to be better from what I understand as far as right track is concerned. Still can't wrap my head around the pilot line switch on control valve having no effect.
Back again to square 1. Take all 4 travel pilot lines off the vale bank. Put gauges in them. (4). Use your travel and watch the pressure build up and make sure that only one is getting pressure while activating only one travel function. Try your M1 mode and rabbit and turtle speed. Make sure they all effect or don't effect the engine rpm in the exact same way. If there is a difference, swap the travel pilot pressure senders under the cab.
I pulled control valve today, wasn't to bad did it in 5 hours. There was just to much funny stuff going on. Also switched forward travel pilot lines and they did change tracks so that was a wild goose chase, I guess I should of confirmed that myself the first time but my uncle was running it and its his so what can you do. I did swing cycle and time was 1:19 boths ways p mode. One other thing I discovered while I had it out of the shop was the arm was running both pumps in and out also bucket stops in and out when pulling arm in and bucket stops when booming up, bucket in also stops when left side is in air and traveling but travel speeds up the more you try to roll bucket in. Please tell me that this is all control valve related because that would suck if I pulled it for nothing. I did go through checklist in manual for troubleshooting internal checkvalves inside valvebank and seemed to be more than one leaking, but there was really no symptom that best described behavior so not sure how reliable that is. And did swap the pressure sensors under cab and now auto idle seems to be working as well.
I would have done a lot more testing before yanking the V/B. You have what seems like numerous problems. Good luck
Well there was a couple machanics that told him that was the move to make on it and have been spending alot of time on it. Any thoughts on the 2 pump stroke when arming out? I also found stuck spool on "sb" of solenoid valve 1.
So we split valvebank and found a couple checkvalves pounded abit and the aux spool was pushed upward about 3/64" and stuck in that position but a couple taps from bottom side and it free right up. So would be that 3/64" on the spool be enough to disrupt flow sense? because it was pretty low before.
Seems to me like a flow issue and having a common pump supplying the two affected functions is the first place to check, are the pumps genuine reconditioned units? Have they been flow tested after repair? Is the pump control pressure correct for both pumps? Is pump case drain flow to high ? . Dont get too deep too quick first check all filters/screens/oil. Let me know what ya reckon. Yatesy.
The pumps were done by reputable place, but don't know if they were flow tested. How do I check pump case drain and how to adjust? And as far as pump control pressure that is where the problem is I beleive. The flow sense is 300psi on front pump and 100psi on rear pump at idle work mode #1, but rear flow sense goes to 300psi when changed to work mode 4 precision. The valvebank is going back in today with new springs and o-rings and I still have gauges to troubleshoot if needed. Any and all help is appreciated.
Hi johnny, Can you send over a copy of the hydraulic diagrams so i can have a look cheers mate.
Anything specific because I will have to get them from work today but should be back home in 6 or 7 hours.
PVC FAULT Codes So I reinstalled valvebank with no change in performance, but did manage to pull fault codes from PVC 4 25 26 27 28 33 35 36, is there any way to erase these codes without Dr.ex because I believe some of these are not current, I would like to generate new codes to work with. Please respond
Disconnect the battery, I believe that will erase your codes
How did you get it to give you the codes?
I used jumper wire on open connector(white in color) down by fuse block behind seat. Procedure was in the john deere 892 manual but nothing on how to erase.
you may have already erased some without knowing it 1.Remove jumper with key on that should get partof them . 2. Remove jumper with key off that should get the others. 3.Test again
Finally resolved this issue yesterday. The "rebuilt" pump i installed had regulator all forked up. There is two spools and two sleeves inside which were reversed , how they never caught that? even one of the plates that mount on either end was backward and that is what caught my eye. This pump was also sent back and they said it was missing a spring so i guess they put a spring in and sent it back- it still didn't work. these guys cost the boss bout $4k in testing and overhauling the valvebank. so I disasembled and reasembled regulator correctly and all problems corrected. So much for having a ticket still don't make u a good mechanic only experience does i guess so thanks to everyone for the assistance.
This machine's hydraulic pump regulation is controlled electrically. check its pump control solenoid vale & DP censer.
The electric solenoids were overhauled first and that was what led to the pump swap except the rebuilt pump came with backward reg internals.the problem was with the internal spools and sleeves being reversed in the regulator, I repaired it already and it is running great and back to work. and thank you for your input soujit.