Komatsu pc200-5 slow operation after hammer hooked up.

[davecampbell]

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

 

[Ronsii]

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.

 

[davecampbell]

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.

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.

 

[Ronsii]

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.

 

[davecampbell]

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.

 

[John C.]

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.

 

[John C.]

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.

 

[davecampbell]

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.

 

[BigWrench55]

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.

 

[BigWrench55]

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.

 

[davecampbell]

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.

 

[davecampbell]

If the wire to the TVC solenoid is broken, the pump would have gone to full stroke and overloaded the engine.

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.

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.

yes, I have strength but no speed.

 

[davecampbell]

If a restriction causes slowing, would it labor the motor? This thing is spinning free.

 

[Ronsii]

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.

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....

 

[davecampbell]

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.

 

[John C.]

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.

 

[davecampbell]

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

 

[davecampbell]

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.

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.

 

[davecampbell]

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.

 

[davecampbell]

I bought a new filter for it today. No change.