I installed my hammer/breaker and now everything operates In slow motion. I thought it might be a problem with the pilot bypass valve because it seemed to work better after I messed with that. I went and bought plug and cap and it didnt make a difference. I tried turning in tvc valve, no difference. The hammer is plumbed with return straight to filter. Could there have been enough crap in the hammer to plug filter? There is a plug in the other port of the control valve where I'm assuming the line they moved to filter would go if used for a thumb. Hours are at 6666.3
I know this won't help you now... and I don't know much about how komatsu plumbs the 200-5 but anytime we get a new(used) attachment I never hook up the return hydraulic line!!! always have someone or something hold it into a clean five gallon pail with some plastic shrouded over it so's they won't get soaked a few seconds of on-time should give you a decent sample to see if you want to purge some more or go with it. We bought a breaker for our 120 from an auction and the crap that came out of it when I did this purge routine looked like it belonged in a septic tank I ran about 15 gallons through it before I was satisfied it wasn't going to contaminate our machine... It might be worth it for you to run a few gallons to a clean bucket and just see if there is still crud in there... I know you have already ran it probably quite a bit unfortunately but into a bucket with less restriction might just knock out more crud, just make sure you have something close by to hammer on.
That is what I should have done. Someone has welded a bung on the top of the filter housing and plumbed the hammer return in there. Hopefully the filter caught the garbage and I can get away with just a filter change. I'm sure I wont be able to get a filter tomorrow for it though.
Yeah, that sounds like a strange setup... I know when our 120's hammer is active it has some pretty high pressure pulses coming out of that return line not sure what that would do to the filters innards but I don't think the filter would last long before something ruptured inside it.... or that pressure would be backing up into what other lines are connecting to that side of the filter... I seem to remember reading somewhere that a dedicated line to the tank was best for lots of reasons to do with excessive pressure on the return circuit causing issues with other stuff. hopefully someone else pops in with more detailed info than me... I know there are a few guys on here that really know hammers.
So I seemed to have found my issue and corrected it. But now I'd like to be educated on it. I found a broken wire that looks to go to a solenoid behind the block that my TVC valve is located in. Seems to have constant power to it. Apparently it was happenstance that it broke when I installed breaker.
It sounds like you plugged up the jet sensor lines in the bottom of the main control valve. I suppose you hooked up the hammer only on the auxiliary spool on the five spool valve. There are two #4 hoses coming off the bottom of the valve and going to the pump. There will be a cartridge relief valve next to those two hoses. One of those hoses hooks to a longer fitting threaded into the valve body. The fitting has a small orifice that likely needs to be cleaned out now. That hose may be plugged as well.
You got your post in before me. If the wire to the TVC solenoid is broken, the pump would have gone to full stroke and overloaded the engine. The only other wires I can think of right now go to the throttle control motor.
I was wrong on 2 counts. The wires go to a solenoid on TOP of the TVC block. With the wires hooked up it works at speed for a short time a d then goes back to slow. When slow it never labors the motor.
Speed is to flow and power is to pressure. when you have weak hydraulics then you have a pressure problem. In your case you are having a speed problem. Which means that you are not getting the flow. Without being there I can't give you more help than that. sounds like you are having a internal leak in the system. one easy way of finding this is with a temp gun. Start with the discharge side of the pump and follow the path of flow from there. You will see significantly higher temperature wherever your internal leak is. This isn't guaranteed method but it can help. Good luck to you and I hope this will help.
After rereading your post. I would start at the filter. It's possible that some junk from your hammer return clogged the filter or damaged it. That would effect your flow as well.
So I let it sit an hour, fired it up and it worked at reasonable speed for about 2 mins. Once it slowed down, I cut the wire to tvc solenoid and there was no change. I'll let it sit another hour and try it again with the solenoid disconnected and see what it does.
That makes sense. I looked at a pc220-5 for sale a couple of weeks ago, and it was at full stroke all the time. yes, I have strength but no speed.
If a restriction causes slowing, would it labor the motor? This thing is spinning free.
Hopefully you have cleaned out any hoses and places mentioned in previous posts!!! and changed filters!!! otherwise you may be turning a hundred dollar problem into a ten thousand dollar problem....
Since it's a holiday, I couldnt buy a filter. I cleaned it as best I could with gasoline, but did not get anything significant out of it.
If the jet sensor is plugged, the pump will not stroke up even with the TVC disconnected. There has to be a differential between the jet and the tank ports to make the system work.
I fired it up with solenoid disconnected after letting it set for an hour. It would load the motor but didnt stall it. Within a couple minutes it was back in slow mode. Where is this jet sensor located? Is that solenoid a simple on/off, or is it modulated in some way? Codes are H2 15 18 23
Somehow I missed this post until just now. Is there a jet sensor for each side of the control valve? I'm seeing what I'm guessing is the cartridge relief valve and two hoses on each side. I'm not seeing one that is substantially longer than the other though.
I pulled out this fitting. It had small offices leading to a cross drilled hole. I was able to blow through all of them fine. Didnt see any dirt. Symptoms continue to be the same but the amount of time it works correctly before slowing down seems to be slightly longer.
I bought a new filter for it today. No change.
I doubt this will help however here goes... we have one machine with what seems like a single position valve pedal. It's not it will fire a hammer a few times "backwards if you will. It won't hit real hard and it is definitely not happy. The reason I added this is if you waited awhile and went back to it... it would fire a few times and stall at full stroke.
Mine is the whole machine. You don't even have to be using the hammer. I've just checked pick up screen in it. No trash in it, but it is missing most of the outer fine screen. I wonder if there could be pieces of it causing problems somewhere.
I have three questions for you. Did you pull and clean the orifices on both valve bodies? The second question is for understanding purpose. When you say the machine is slowing down, do you mean the hydraulics are slowing down, but the engine is still running at the same speed or that the engine is slowing down and all the hydraulics are running slow with it? Have you checked the diodes on the computer for faults? Here is a video showing how they work. If the pump control diodes are flashing, there is a problem. If the hydraulics are all running slow, you will need some gauges to read the controls inside the pumps. I did a video on Dash 5 hydraulic tune but it is a PC400-5. The system works all the same, the ports in the pump might look a little different. Good Luck!
I didn't realize that there were 2 orifices. I will look for the other one tomorrow I have the tvc set so that the engine labors some when its working correctly. On initial operation that all feels normal, but when it slows down, the engine spins full rpm and never even labors. When it slow down, every function is affected. Ive watched your videos and they were very informative. I purchased 3 gauges and 2 hoses. I had an extremely hard time finding the fittings to tap into what I thought was the right place to test main output pressures. I still need to buy hoses and fittings to test pilot pressures. My monitor panel has not worked while I've had the machine. I found one bad fuse but it didn't fix monitor issue. My plan is to fix all the windows and then try to trouble shoot the monitor when there is a reasonable expectation that I can keep it dry enough to live. The codes on the computer are h2 15 18 23 Thanks for your help.
The codes tell a story. H2 just means that the mode switch on the monitor panel is in the HO mode and the power setting is in S or 2. The 15 code is disconnection in the travel speed solenoid. The 18 code is a disconnection in the TVC solenoid and the 23 code is a problem with the front pump pressure sensor. That 18 code might mean a problem in the solenoid coil or possibly and issue with a wiring harness. If the other jet sensor is clean, you will likely need to do a hand over hand check of the wiring harness going back to the cab plus checking the solenoid coils and the front pump pressure sensor.
I found and repaired a broken wire to that solenoid. Does it take a while for code to go away, or do I have another issue there?
I found and checked the other jet sensor. No change in performance. The 18 code is no longer showing. just h2 15 and 23. The high speed solenoid is disconnected. Is the pump closest to the motor considered the back pump?
The pump closest to the motor is the front pump.
the front pump pressure sensor is the jet sensor i pulled and checked, correct? or is there another sensor I need to be checking/replacing?
The pressure sensor is on top of the control valve and is electric. The computer uses it to tell when to shift the travel into low range. The jet sensor is on the bottom of the valve and is just an orifice.
my high speed travel is disconnected because I had an issue with the left track going into high every time it went forward. It turned out to be the seals in the swivel leaking pressure from forward to the high speed and one track motor does not seem to be shifting to high speed. So I never tried to reconnect it. It does do a weird hesitation when tracking sometimes. I dont see how that could be it unless I disconnected the wrong solenoid. So do you think that the pressure sensor malfunctioning is a possible cause of my slowing? I went out and found the pressure sensors. I swapped the plugs and fired it up. Code switched to 24, so I'm assuming bad sensor.
Sensor from komatsu is $565 and ebay and Amazon has them for $50 from China. Will the Chinese one work, or do I need to pony up for genuine?
Nice job on checking the sensor. The 24 code is the rear pump sensor so you figured that out well. The sensor as far as I know would not be the reason for the slow operation of everything hydraulic. I've seen plenty of machines running with that code and the operators didn't know it was even a problem. Just a thought, have you checked the toggle switches under the jockey box on the back of the right side console? They should both be pointing towards the rear of the cab in the normal mode.
I'll go look
Yes, both red switches are towards the back. I didnt even know they were there. Looks like some emergency override switches?
What would happen if I disconnected the hoses between the sensors and the pump and started it up? Could I compare flow out of them to see if they are similar?
One switch is the over ride for the TVC and the other releases the swing brake all the time.
Tvc override, does that go to full displacement?
It only goes to about three quarter torque from the engine. It bypasses the computer and sends current through a resister and then to the TVC solenoid.
I'll test tomorrow. I feel like it's the pump flattening out because I dont hear anything that sounds like hydraulic restriction and because the motor doesnt load. So it sounds like that solenoid Is modulated by the computer during normal operation as opposed to a simple on and off solenoid. Could the solenoid be going bad? I have a pc150-5, maybe it will have the same solenoid that I could interchange as a test.
You are correct about the computer modulation. You can check the solenoid by removing it and checking the plugger. Turn the key on and hold your finger over the plunger on the end of the solenoid. You should feel it move in and out as you shift the mode switch on the monitor panel. The other thing you can do is reinstall the solenoid and disconnect the harness connector and then operate the machine. The pump should be able to overload the engine in that case. You can check the pressure coming out of the solenoid as well. You can also check TVC pressure. If you look at the center of the pump and in between the two control blocks on the pump, you will see an eleven sixteenths bolt head. That is the passage for checking the TVC pressure. With the engine at high idle, mode in HO and power in H and the controls in neutral, the pressure should be somewhere around 360 PSI. With two pumps running with a control dead headed over relief, you should see somewhere around 270 PSI.
I tried the overide switch, no difference. I went out and cut the wire to tvc solenoid (the plug has been eliminated), still no difference and no load on motor. So I pulled the solenoid and touched the wires to 24 volt and it pushes out. It doesnt retract, but with power removed I pushes back in smoothly. I tried pushing down in the center of the hole I removed it from to see if I could feel the spring it moved against, but I felt no movement. Maybe it opposes hydraulic pressure? I looked in vain for the 11/16 test port. Could not find it on my 150 either. The only 11/16 head I could find looked like an adjustment of some sort on the bottom of each control block. There is a hard line between the two control blocks. Could that be carrying tvc pressure between the two blocks?
As I recall the fitting is on the side of one of the control blocks. The lifting eye in the photo is the center of the pump. As I recall, the fitting will be on the forward valve block. The fact that the solenoid moved usually meant there was no problem with it. Judging from the oily dirt all over the pump in your photo and the age of the machine, it is probable the the piston inside the valve block that the TVC solenoid pushes against is stuck in place. The oil that operates all those controls is not filtered directly by the return filter. There are small button looking filters inside the pump that by this time have holes poked through them. It looks to me like you will have to at the least remove the control valve blocks, dismantle, clean them up and reassemble with new seals. Just a guess at this point based on experience.
I had an old 888 case, it had a shutoff on the suction. I dont see that on this one, do I just need to drain the tank to do this?
I would just drain the tank below the level of the pump control valves. If the oil is old, I would just drain it all. I use a barrel pump instead of trying to open the drain plug on the bottom.
laying in bed last night thinking through this. It seems like a stuck piston should make it work slow all the time. Since it works at decent speed for a couple minutes before it slows down it makes me think it is either something plugging up as it runs, or some pressure building somewhere that is giving the pump a false signal to flatten out. I am really confused by the combination of a jet sensor in the valve body that is plumbed back to pump controls and the computer controlled solenoid. Is this pump electrically controlled or hydraulically?
Go over to insanehydraulics.com and do some reading up on how some of the komatsu tvc pump stuff works.
I have reviewed that site and find that the guy really doesn't understand what he is talking about on the Komatsu systems. His explanations will just confuse you.
I've been on that site, but I was confused before I got there, so I cant blame my confusion on him. I'm pouring over the hydraulic schematic for my machine and I'm not understanding much of it.
It could just be a coincidence, but it definately started after I hooked up the hammer. I didnt flush the attachment, but since the return goes straight to the filter it seems like any trash would have to have gone straight there and be picked up by filter. Since the tvc seems to do different settings for different functions, could the hammer control circuit be building pressure somewhere that would send tvc a false signal?
It takes time. Focus on the pump controls first. This system uses pilot oil to stroke and destroke the pumps. Pilot oil is provided first to the TVC valve and then the NC valve and finally the Cut Out valve. The TVC valve supplies both pumps, so your observation about the cross over tube is correct. Since both pumps seem to be affected, it would be logical to assume the problem is in the TVC valve block. You can see the actions of the pump control valves by following the dotted lines from those valves back to their origins.
The TVC is only controlled by the computer. It is a regulator valve that controls pilot pressure.
Since I couldnt find the pressure tap for pilot pressure I put it on what I think is a charge pump. Looks like a small gear pump piggybacked onto main pump. I got a little over 500 psi operating cold. Ran the machine until it went into slow mode (about 15 min this time). Still maintained 490 psi. Then I went hunting for the pilot tap again. I believe I found it on the front side of front control block. It isn't even hitting 100lbs with operation. About 60 at idle and drops when motor is pushed to high idle. That seemed strange to me. Then hits about 80 with boom up topped out. I'll try to let it cool off enough to get pilot pressure readings with it operating cold. I'll also try to upload a video of pressure guage on pilot pressure.
Let I sit for a couple of hours and saw over 200 on pilot pressure. Only lasted about 15 seconds. So now, what can cause loss of pilot pressure?
You have a piston stuck in the TVC valve. Get a hold of a parts breakdown so you can see how it comes apart. You can pull off the end plates to get access to the piston. I believe there is a spring on the opposite side of where the solenoid plugs into and you have to push the piston out. Make sure you note the orientation of the piston when it comes out. I can't recall if it has to be in the right direction or not, but I seem to remember that it does.
Is it just sticking when it gets warm?
It likely has crud in the bore.
It had been working when I first fired it up, and then slowing down after it ran a bit. This morning I went out and cleaned 100 mesh screen. Then fired it up and it was slow right from get go and pressure never reached 100psi. I was hoping that when i cleaned the screen i was going to get good pressure. I would sure like to be able to tell where on the hydraulic schematic I have my pressure tap at.
looks like that is a pretty easy job with the exception of draining hydraulic tank. Is it possible to improvise some plugs to put into the side of the control block while I disassemble and clean the tvc valve? If I'm reading the schematic correctly, looks like 4 passageways to plug.
Looking at schematic, it does not look like the tvc valve is between charge pump and the control block that I have my guage tapped into. I got 500 psi coming out of charge pump so I'm losing a bunch of pressure between those 2 points. Looks to me like there are some screens in the control blocks, I'm thinking when I tear into it, I'm going to need to tear apart both control blocks too. View attachment 208199 a
The TVC valve is the first valve in the pump control circuits to get pilot oil. Pilot oil then is routed to the other valves in line. You aren't loosing flow, it's just not being opened up to flow down the line because that regular is stuck. If you tear off both blocks on each pump, which I think you need to do, you will have to drain the tank. There is a lever that goes down into the servo piston area which is open to the hydraulic tank. There are button screens in the blocks that will need to be replaced.
I got the blocks of and started with the tvc. There is a plunger that sticks and does not slide freely.
I used to blow the block out with ether and then air. I'd chuck the spool in a lathe or even a drill press if the chuck was big enough and polish it with crocus cloth. Even a Scotch Brite pad with work. Plenty of oil on things when you put them all back together. Nice Work!
I'll buy some crocus cloth tomorrow and get after it with that. I also found a pressure tap that I did not recognize as one. I'm thinking it's on the bottom of the servo adjuster. What pressure would that be reading?
If you watched the Dash 5 tune up video, that is the fitting on each pump you tie into to read the actual oil pressure on the servo piston. The pressure reading will be situational. When the Jet Sensors are at 300 PSI difference on their end, you set the NC pressure at 70PSI coming out of that fitting. When setting the cut out, you put a function like boom or stick over relief with the mode in H0 and H and the main reliefs set at 4,500 PSI, the pressure there should be at 70 PSI. After those are set in the right situations you can set the TVC for how much RPM you want to pull out of the engine. I'll add or subtract TVC pressure to get about 150 RPM drop on the engine. After all that I go back and check and reset the NC and Co as needed.
I was very careful to not change any of the settings when I disassembled and cleaned everything. It has better pilot pressure now, but when I go full lever on tracking it pulses the speed of the tracks. If I push the levers a little less I can track smoothly.
Do all the functions on the machine work now except the surging part? You are going to need the gauges and then set up the hydraulics like I did on the PC400 in the video.
Yes, and I still have my guage hooked to the back of the front control block. It pulses with the tracks. I haven't actually tried using it, but everything else cycles good. I need to go buy 2 more hoses and one more guage so I can do what is in the video.
The surging seems to have gotten better. Could it have been air in the system? Trash that I missed?
There are a whole bunch of little passages and small spools and lands in those valves that anything is possible. If it get better over time, I think that's a great situation.
I put in 9.3 hrs with it yesterday and track surging is completely gone now.
That is super news! Nice work. Is the machine performance what it was before?
I've used this machine for several jobs with it working well. Yesterday I blew a hose on the hydraulic thumb. I had an old hose that I used as a temporary fix and within 5 min it displayed the symptoms of slowing down. I could let it set a few minutes and it would work good for a couple min. I thought my screens had plugged up in the pump control blocks again, so I drained the hydraulic fluid and pulled them off. I boiled them and blew ether through them. Reinstalled and still has same symptoms. I plan to hook a guage up to pilot pressure again to verify, but feels like it is losing pilot pressure to me.
Could it be air in the system, some machines you have to pressurize the hydraulic system after cracking it open....
So you installed an old hose and now you have problems again?
Where exactly are these screens that you cleaned? Thanks
Yes the first time it did it was the first and only time I used the hammer. This time I blew a hose on the same circuit, but it was being used for the thumb. the screens are located between the control blocks mounted to the hydraulic pump.
So you have to take the control block off to get to the screens?
YES
Do you have a picture or diagram showing where the screens are? Thanks
I'll try to get on the parts breakdown to show where those screens are located. I took the valve apart that the solenoid sits on. Found some grit in that, but cleaning it out did not help. I can't find my low pressure guage but put the high pressure one on the elbow coming out of small pump ( finger pointing to port in pic) and looks like approximately 500 psi. Then I tapped in behind the control valve (pictured with hose hooked to it) and only got about 100 psi. Any ideas on where I could be losing pressure at? Thumb and tracks work fine, but seems I dont have enough pilot pressure to work anything else.
As I recall the pilot pressure is set at 426 PSI so 500 will make everything work just fine. The other connection you are plumbed into is the TVC outlet pressure and it is one of the controls for both pumps. The thumb and left track are the first control valve spools on each valve. It sounds to be like you have some crap stuck in both jet sensor orifies. Those are mounted on the bottom of each valve. You will see two hoses down there each connecting on an elbow that will have a small 1/8" pipe plug in the elbow. You can plug a gauge into each and start the machine up. there should be about 300 PSI difference between the two gauge readings with the engine at high idle and nothing being moved. If you don't have two gauges, then you will have to take the fittings out of the valve and makes sure they are clean. I usually put a vacuum on the tank to stop the oil from draining out.
So a plugged up jet sensor orfice will affect boom functions but not tracks or thumb?
The left track is the first valve on the four spool valve and the thumb is the first valve on the five spool side. The right track is the last spool on the five spool valve. The fact that both travels are working means that the pump is not the problem.
Could it be a problem somewhere in the pilot system? Seems like that is what does not work.
If it is, it would likely be on the supply of pilot oil to the sticks. I think I said earlier I would try to tee directly into one of the lines to a spool that didn't work and see if you are getting pressure there.
Yes turns out there are screens in the inlet port of the joystick valves. Cleaned those our, and she came back to life.
Where are they located?
Are they under the cab under the seat ?
No, they are right on the intake port of the joystick valves inside of the armrests. I had to pull both armrests apart.
Do you have a picture that is zoomed out? Is that screen/bolt holding the line on that I see disconnected? If so is there one on every line. Sorry for all the questions but you have been a big help, among others (John C. And Lauchau).
Sorry, I just snapped the one pic and then reassembled it. I think the only line with the screen is the supply line. mine were marked with red bands on them.
Sorry, I just snapped the one pic and then reassembled it. I think the only line with the screen is the supply line. mine were marked with red bands on them.
Sorry, I just snapped the one pic and then reassembled it. I think the only line with the screen is the supply line. mine were marked with red bands on them. Are you working on one that has the same symptoms?
That's pretty cool, I didn't know there were screens in there.
Thanks, I guess I’ll be ripping apart armrests and joysticks this weekend!
Hi all, I'm having this exact problem with my pc400-5. Reading this through, am I correct that the solution to the issue was a gunked up TVC? You cleaned the screens and polished the spool and it worked after that? This caused your issues in spite of your TVC valve not being hooked up/used? My TVC doesn't even have a wire to it, so I assumed it couldn't really give issues. I replaced the entire pump while I was having a separate issue with an identical machine, it worked well for about 14 hours then all my issues returned. My TVC is gunked up again? Did I read it correctly that cleaning the screens to your controls in the cab fixed an issue with a single control? It was not related to your fix of the overall hydraulic issues? Thanks in advance, been a stressful mining season with my best running machine being down for a month
Update 3 hours later. Problem solved thanks to the good info here! Not the TVC for me but close by. There's 3 small ports with screens where the servo contacts the pump. One of the three was plugged up. Incidentally, if anyone knows where b in the attached picture gets its oil supply from, that would help me track down where the gunk is coming from. Thanks for the information already on the thread! Machine has been down three weeks, big load off!
Wow! Very cool you could use this information to solve your problem. I worked through the whole thread and read it but did not understand everything I was reading. Good on you for being able to track it down.
Yeah! I had to read over a couple spots twice but it certainly helped. Gave me reason to look over the area again. You having a similar issue? Mine was identical to what the previous guy described
NO! And don't want it. My lurking is pre-emptive...hoping I can recognize symptoms/causes, learning as I wade thru the jargon and detail.
Oh yeah. I learned a ton on this fix but expensive education! Good luck to you