Komat'su PC60-7 --Just Purchased Used--Some Questions

[Mark A Weiss]

I bought $311 worth of new tools, including a 25" breaker bar.

The seller recommended this company for hoses:
https://www.discounthydraulichose.com/hydraulic-hoses.html

Most of the bolts seem to be 17mm. I got 6 point sockets and that was a wise choice because many were rusted in and even 50lbs of force on a 25" bar it took to break free most.

I'd been looking at excavators for a year, but most asking prices were in the 40s to 60s. This guy was asking under 30 and I negotiated down to 27 5. I did ask if there were any known problems. The machine operated and sounded great, so that gave me a sense that the guy had taken good care. All the joints had fresh grease on them and everything looked lubed. I was unaware of this forum prior to this week.

Mainly bought as an investment that would be safer than keeping my cash in a safe for the past 60 years, seeing as the value was dropping rapidly this year.

After 9 hours of struggle, I managed to get the spliced line out of there and pull ropes in place for the new line.


The two pull ropes, one to the pump, the other to the front.

The pull rope out the front, ready to pull in the new line.


The other end of the line at the pump. All openings sealed with plastic and a twist tie.

So now I need to find an 11' hose of the correct spec with connectors.
I'm tired, my back hurts and my arms are all scraped up.

 

[John C.]

These all run in the 300 to 500 PSI range on the pilot system. Single wire hoses are fine. Some other brands of excavators use plastic tubing. You are probably looking at around $40 per hose replacement. The labor to change them will be far more than the cost of the hose.

 

[Mark A Weiss]

I've used about $700 of my own time (normally I'd be fixing amplifiers at $80 /hr) today just getting the old line out and snaking the pull ropes for the new line.
Yes, these appear to be low pressure lines.
The last section that goes under the operator seat to the front controls was a challenge to remove. Something was preventing the connector from getting past something under the floor in an area I cannot see. Ended up cutting the other end off and attaching rope to that and trying to pull that through in opposite direction, but the lump got stuck under the floor again. So I fished a 10 awg wire from the front and hooked the rope to bring it the last couple of feet, cut the other end off the bad hose and just pulled it through with a great deal of friction. Hopefully I did not damage any other lines with all the tugging I did to remove this one.

Now to find a place that can make me up a line to match this one, including the same connectors. Hope I can find a place that will make it while i wait or has an off the shelf exact replacement.

I'm hurtin' pretty bad right now. Right heel in pain, back hurts, bruises and scrapes on both arms. Tomorrow's another day!

 

[John C.]

Sorry to hear of your pain. Many here have been doing it for more than thirty years. I can't figure out how it gets in the blood so hard. We are wired for it in the head I guess.

 

[Mark A Weiss]

Having an existing back injury from a rear end collision 14 years ago limits my ability to get into positions that some of these jobs require.
I've been in the electronics field for about fifty years, so working on machinery is a whole new world for me.

I'm shopping for the replacement line, but am not familiar with the sizes, fittings and terminology.
Am I correct to assume these are 1/2" lines with 1/2" NPT male SAE fittings?

 

[Welder Dave]

Best to take what you have to a hose shop unless the OEM lists all the info. Wouldn't want to guess and get the wrong hose or fittings. Repairs can be a real pain sometimes and hard on the body. Having recently gone through the most severe back pain I can really feel for you. I won't be doing many repairs anymore unless they're fairly easy. Unfortunately my back pain was a result of cancer. I had compression fractures in 10 of my vertebrae. 5 were repaired with a bone cement procedure but I still have 5 others that may or may not need the procedure. Most days I'm OK but sometimes my back aches pretty bad.

 

[John C.]

They are generally known as Komatsu fittings which are JIS or Japanese Industrial Service. I don’t remember if they are #4 or #6 size. Take the hose with you and check a male fitting in the female hose end to be sure you have the right size before they cut the new hose from the spool.

 

[Tags]

You could run over to Levine Automotive for that line, they can make them up. You can also just Google “hydraulic repair in Connecticut”, and you will have lots of choices, take the line with you wherever you go so they can match up the fittings and the length. It is next to impossible to go online and try and buy a premade hose. The typical way to do it is to remove the hose and go to a local hydraulic repair shop, mostly all shops will do it while you wait.

 

[Mark A Weiss]

Good suggestion about Levine's. I will call them. They have two shops within 20 mins of me.

Here are the dimensions I was able to measure.

Is it a problem to get JIS fittings locally?

Sorry to hear about the severity of your back issues, Welder Dave! Cancer sucks. I have it in my prostate and colon. My days are numbered.

 

[Welder Dave]

Very sorry to hear that. Take it easy and try to surround yourself with positive people like those on here. It's made a huge difference for me. Cancer does suck!

 

[Mark A Weiss]

What's the best way to drill out the bolts that broke off due to being rusted in under the house? I'll need to deal with that very soon. About 60 dollars.

I'm at Levines now waiting for the hose to be made. They have hydraulic fluid I 5 gal can for $39. Think I'll grab a can to get me up and running temporarily.

 

[Mark A Weiss]

Well I got the new hose about 10' of it and I got it snaked through only took me 2 hours but then I tried to screw the connector on and it's too big.

 

[Kobelco ireland]

Are both end fittings the same size.

 

[Mark A Weiss]

I'm at Levines again. They don't have nipples to check the old fittings for fit. They look the same though.
I'm waiting while they check the warehouse as the don't have the smaller fittings in stock.

Super frustrating after I spent 2 hrs fighting obstructionsunder the house the the fittings would not snake through.

 

[Tags]

Uuuugggggghhhhhh.....so sorry to hear that Mark. Hope you get it squared away. I have had that happen before when I've been in a pinch and had a hose made by a place I don't regularly use, very frustrating. I just mentioned Levine because I figured one was close to you, and actual hydraulic repair place is always a better choice mostly because they are more knowledgeable about fittings and such....sorry again....I hate to say it though, get used to it, it's very hard to find good people in the service industry that care enough to do things right, they are out there, but they are few and far between unfortunately.....

 

[Mark A Weiss]

Yeah the young kid that made my host didn't seem like he was all there. Anyway I finally found a place called T and J hydraulic over at 5 star street in Danbury and they can make anything at quarter inch and above. So they made me the right hose

I was able to replace that damaged hose the one that had displaced in it. That got the hydraulics working again however the right travel lever still leaks hydraulic fluid and there's another hose directly behind it that I found that has a pinhole leak. So now I gotta replace that 1 too.

 

[Welder Dave]

The good news is you're finding the source of the leaks. Sometimes it can be quite difficult to find where a leak is actually coming from. If Komatsu uses fittings that aren't standard a non hyd. shop could be clueless and just pick a fitting that looks close. Replacing a couple hoses isn't too bad and hopefully fixes your problem. It's good you found a hyd. shop that can make your hoses. I hope you got a full refund on the hose with the wrong fittings. It would be different if you had ordered it online but you took the fittings in to match up.

 

[John Canfield]

On my previous 15 year old Kubota tractor I had a hydraulic hose fail every two or three months for over a year, then I decided to replace all of them, should have done that in the first place.

Then one lift cylinder started to leak and I had that rebuilt. Then a few weeks later the other lift cylinder started leaking, had that seal replaced.

Recently I noticed my boom lift hoses are looking pretty tired.....

 

[Mark A Weiss]

I did get a full refund from Levine, so it was just lost time (about 3 hrs) and a lot of extra bruises.

Tomorrow morning, I'm going to ask my wife to wiggle the line while I go climb on top of the control valve and look to see which hose moves. Then under the house to do the same. Then to try to pull that hose and take it to T & J for a replacement build. (BTW, they are excellent.. it was nearly 5pm when I got there and they made me a new hose in about six minutes. Cost was $80 with tax.) Only thing is the new hoses are fatter and won't fit in the plastic looms that are held by those wide clamps under the house. I will have to cut the dividers to allow the bigger hose to set down in there so I can bolt the clamp up.
I probably need a bunch made this length, as many seem to go to the same general end points.
The new hose is 5800 PSI rated. 10' 6" was just perfect.

It's a never-ending thing, just like with maintaining classic cars. I got me a used Silverado last August and put some money into it to get the brake system good and a new radiator. At least now I have a good work truck. This excavator isn't being used for commercial work, just projects around my property, so I expect once these lines are replaced, I should have a respite from such matters.

As long as I don't use the forward position on the right travel stick, the leaking stops. So I managed to continue digging my tree stump this evening, traveling backwards and doing jump turns to avoid the forward position. I noticed with the pilot line replaced and 5 gals of AW46 (Levine had it in stock for $39) added, the hydraulics seem stronger. When I pulled on the stump with the bucket just a bit, it will easily lift the back end of the machine now, even with the blade down. I'm digging around and busting up the tap roots all around the stump first.
Workarounds. Tomorrow, hopefully I get that other bad line out and replaced.

I want to express my sincere gratitude to you fine folks for all the encouragement you've given me. I was "that close" (holds up a .016" feeler gauge) to giving up and looking for a service mechanic. Your step by step recommendations gave me small goal posts to pursue and eventually, I reached the finish line on that first, difficult line replacement. Now I know the drill, so the next one should be more straightforward, though still a &*%$ struggle.


One final thing... any advice on a good way to drill out the broken 17mm bolts that are rusted in (they hold the bottom service panels in place) on the underside of the house? I've got a total of four that broke on both panels.

 

[Welder Dave]

Normally the easiest way to remove broken bolts is to weld a nut or flat bar with a hole in it to the broken bolt and the heat will break it free and it will spin out. Being overhead and having to crawl under the machine might make this difficult. If you can get a center punch centered on the broken bolts maybe a left hand drill bit would work? A normal drill bit and EZ out might work too. If it's just for a cover plate may not be too critical or maybe you could drill a new hole(s) for the cover plate and tap the holes on the machine if the broken bolts are really stuck bad.

Kudo's to Levine for giving you a full refund.