Komatsu pc200-5 slow operation after hammer hooked up.

[Mother Deuce]

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.

 

[davecampbell]

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.

 

[John C.]

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!

 

[davecampbell]

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.

 

[John C.]

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.

 

[davecampbell]

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?

 

[davecampbell]

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?

 

[John C.]

The pump closest to the motor is the front pump.

 

[davecampbell]

the 23 code is a problem with the front pump pressure sensor.

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?

 

[John C.]

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.

 

[davecampbell]

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.

 

[davecampbell]

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?

 

[John C.]

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.

 

[davecampbell]

I'll go look

 

[davecampbell]

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.

Yes, both red switches are towards the back. I didnt even know they were there. Looks like some emergency override switches?

 

[davecampbell]

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?

 

[John C.]

One switch is the over ride for the TVC and the other releases the swing brake all the time.

 

[davecampbell]

Tvc override, does that go to full displacement?

 

[John C.]

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.

 

[davecampbell]

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.