Komatsu PC200-3 hydraulic line?

[bunkydad]

I just bought a 1989 Komatsu PC200-3 excavator. It runs well but needs a little TLC. There is a hose that runs from a tank in the area of the hydraulic pump. The line runs down the boom to about 2 feet above the bucket. The end looks like an air line quick connector. The other end enters the side of the pump area behind the cab.

Any ideas what that would be used for? Can I remove the lines and cap the ends? Remove the tank off the door panel?

 

[John C.]

That isn't something that was original to the machine. It looks like there are two hoses on that tank. Any idea where the second hose goes?

 

[bunkydad]

Here is where the hose come to on the dipper.




On end connects to the side of pump housing area and the other runs out to the dipper. I don't see any electrical connections or switches to control it, whatever it is.

I don't want to take it off if it's something important.

 

[John C.]

None of that is part of the machine as it came from the factory. I can think of a couple of off beat reasons for someone to put that tank there and none of them are good. Where on the pump housing does the other hose connect at?

 

[bunkydad]

I'll have to take off the outside panel and check. Even the former owner had no idea. He suggested it was a low pressure hydraulic line. I'll open it up this weekend.

Another question: Are the larger hydraulic lines on either side of the dipper for an hydraulic hammer? The machine has a JRB coupler and I was hoping to find a used hammer to use on some rock. I don't see in the cab a way to activate the hammer if that's what they are for.

 

[John C.]

They are for an attachment but you have to see if the machine has a three way valve for the hose on the right side of the boom. A compactor will usually have to return to tank instead of going back through the control valve. You can set up a hammer to return through the control valve but it isn't a good idea. They were usually controlled with an electric solenoid valve with a pedal switch in the cab.

Is the coupler a manual unit or a hydraulically controlled one?

 

[bunkydad]

The coupler is hydraulically controlled from inside the cab. What I can't find is a way to activate the aux lines. There are a bunch of wires hanging in the cab behind the seat but no foot pedal. I still haven't had a chance to open it up to see where that line goes. I plan on pulling off all the panels and pressure washing the inside first.

I notice some of the foam around the radiator is loose and hanging . Is there some way to reattach?

 

[John C.]

There is foam around the radiator to channel the air flow through it. There should be pieces on the sides and top to keep air from bypassing. I remember finding something similar in a fabric store or industrial supply place for replacement stuff if the old was too bad.

You usually only have the foot pedals on machines that were imported into this country gray market. We usually installed a solenoid controlled hydraulic valve and a cylinder actuator on those machines to make a thumb work. Back then I was using a rocker switch on a joy stick to operate the thumb.

 

[bunkydad]

So I finally got around to looking into that hose that runs down the boom to the end of the stick. I followed it back to the pump house and into the tank. The other hose runs into a control box of some sort(?) that the aux hydraulic lines connect to. There is a wire (disconnected) to the box and a selector knob on the top with at least three settings. A friend of mine said the small line might have been an autolube line to a hammer.

I'm trying to find out if I can hook up a hammer to the excavator (if I can find a hammer in my price range). Thank you