1980's komatsu pc200 excavator problems

[BivensRecycling]

I have a late 1980 model trackhoe that is having some problems. All of a sudden it stopped pulling from one side. Also some of the functions are week. The bucket opening and closing is weak and the down force is awful. We were originally told from our local Columbus Equipment that one of the main pumps was bad. We found out 1 was leaking so we sent off for a new one. It came back and didn't fix the problem. So they told us it was the other pump. Sent it off and now it still didn't fix it! Now we have $11,000 in new pumps and haven't gotten anywhere. We just rebuilt the engine about a year ago and up until this point it was the strongest piece of equipment we had, and it's the oldest!! It has some serious sentimental value to our business so scrapping it is the very last option, and we would like to fix it. We have had 2 komatsu mechanics working on it for 3 days now with no luck. And honestly I seriously question their ability to identify any problem. They are the reason it has 2 brand new pumps it didn't need. Any opinions or advice would be greatly appreciated! Thanks!

 

[Innes]

Sounds like you got a faulty Mrv on one pump circuit,I would be asking the mechanics to do a pressure check on both pump circuits, I,m not familiar with Komatsu but have seen this problem on other excavators, if its an 80s machine then I don't expect much electronics apart from maybe a control pressure solenoid to swash over the pumps. Can't understand a mechanic fitting pumps without diagnosing the problem first,hopefully they will remove the new pumps and credit your account as you have been given poor advice/service.

 

[John C.]

Your machine could be a Dash 5 or a Dash 3 model. Please let us know which it is because there are problems like what you are describing on one and not the other. A common item that indicates a bad pump in a Komatsu of that era is brass chunks in the suction strainer in the hydraulic reservoir. It there was no brass in the tank, there probably was nothing wrong with the pumps.

There is no way that only one pump would have been replaced at a time. The unit is two pumps in bolted together casings. There are few to no companies able to rebuild the pumps and then calibrate them to run in your machine, especially if they on have a half of the unit.

The mechanics should have plumbed in at least four gauges to check system and pilot pressures before doing anything with the pumps. That they jumped at replacing parts as a diagnostic procedure should tell you the caliber of their expertise.

 

[MrKomatsu]

$11,000.00 to rebuild Komatsu pumps....wow you got a deal.....do you have a serial# handy?
i will be glad to guide you in trouble shooting your unit......just sayin....let me know