Good day, First up thank you to all the members who have posted tips and solutions to repair the Komatsu PC200. Our new to us but old PC200-6 blew a swing hose last week. Because of the information in one of the threads here, a local hydraulic shop was able to order code 61 fittings and make a replacement hose. They used 5000psi hose. I will order enough of this 3/4" hose to replace all lines of this diameter. My question is: Does this excavator require 5000 psi hose? Would 3000 psi hose be as good? Thank you
Most non-mini excavators built in the last 30 years run piston style pumps and generally have systems that operate around 5000 psi. You will be able to get by with 3000 pound hose for a short time, but it won’t last nearly as long as the 5000 lb hose.
Thank you for the information.
Those machines with flanged fittings normally operate at 4,500 to 5,000 PSI all the time. Running a hose of any less working pressure is dangerous if not at least messy. While working pressure is 5,000 PSI, burst pressure should be a minimum of three times working pressure or 15,000 PSI. In your case that hose needs to be a high quality four wire type usually found at any hydraulic hose and fitting business. Hoses that have screw together fittings are much lower pressures and ratings. In my experience most auto parts stores don't carry the heavy hose and many assemblers there don't understand the difference between a four wire fitting and a two wire fitting.
If you're going to go to the trouble of replacing all the lines, do it once and do it right. Get the hose rated for the pressure with the proper crimped ends. I wouldn't trust hoses with threaded together fittings for anything more than a very temporary patch.
Thank you all for the advise. We will use only 5000 psi or greater 4 wire hose and equally rated fittings. The hose we had made up is this with CODE 61 fittings. It went on and has sealed up without leaking. It is not a JIS as the originals. It does seem to work. Does anyone have a reliable source for bulk hydraulic fittings and hose?
I've been told its pretty expensive to get set up with a hose crimp machine.
JIS is a threaded fitting like a JIC fitting commonly used in the US. A code 61 fitting is a flange fitting using an O ring and split clamps to hold it in place.
Actually there are JIS flange fittings they are the same size as code 61 fittings except the clamps are sized for metric bolts and JIS has a dash 10 flange size the Komatsu flange. JIS simply means Japanese Industrial Standard like our SAE badge. Bad Bob
JIS threaded and JIC threaded fittings are not interchangeable. At least one size of JIC will thread on to JIS and feel like it screws on correctly. Then when one puts a wrench to it, the JIC fitting strips the threads on the JIS male. Fittings are outrageously expensive. Yes, I learned this the hard way. The one hose we replaced used Code 61 flange fitting with the original clamps and bolts on the PC200. It is working. No leaks. There is a local welding shop that makes hoses. Since they can't get JIS fittings, they will press our fittings on our hose for about $5 each fitting.
Huh?
Guess I didn't write what I was thinking. I have new hydraulic hose and new JIS fittings. I cut the hose to length and take it and the fittings to a local business. They have hydraulic crimping machine and crimp them on for $5 per fitting. They also do welding and steel fabrication.
Just to try to help a little more... I operated a hydraulic hose shop for a little while, we carried Parker brand hose and fittings. Our crimper would crimp upto 6 wire 2 inch and we carried most fittings and hose from 1/4" to 2" in 2 wire, 4 wire, and 6 wire. I have seen brand new $800 hose from the wrong shop blow fail almost immediatly and they not warranty them. Hydraulic hoses on excavators can see much higher pressures that many other machines because to the momentum of the iron that is swing and moving and getting leverage used against it. Yes releif valves are supposed to protect the system, but there is still a lot of shock before the releif valve opens in many cases. This is why you should never use a hose that is not rated for the job. I a rule in hoses and engineering, as the size goes up, it takes more layers of wire to hold pressure, so a 2 wire 1/4" hose might easily be rated at 5500psi but a 2 wire 1" hose may only be good for 1400psi. In the past ten years I have seen 2 wire hose labeled for high pressures that Parkers 2 wire was way less rated. There is supposed to be SAE standards, but I don't beleive all companies are maintaining these standards. Also, if the fitting is not the same brand and proper fitting for the hose, the crimp may not be as strong as the standard to which they were made. When you have hoses made by someone, the first thing they should do is figure out the pressure rating. Many times, we would cut the bad hose to see how many wire braids as a starting point. If they just match size and fittings and don't understand the engineering, I would look for someone else. They may make farm tractor hoses successfully all day, but heavy machinery, especially excavators, are a different game. If you spend all the money to replace many of your hoses and they blow within a few years, your will probably be mad. Make sure your guy at the welding shop knows about these things. Also, Code 61 flange is a flange with a 2 pc 4 bolt flange and oring, it is thinner and smaller than the Code 62 which both are different from Caterpillar flanges. JIS is a 30 degree flare with different threads from any other fitting. Some hydrualic books even call them a Komatsu fitting. Although some JIC, which is a 37 degree fitting, can mate and seal with a 45 degree fitting like a gas line, it is best to stick with the proper fitting. I don't understand how a code 61 fitting can be used in place of a JIS. Google Parker 43 series fittings, 71 series, and 73 series fitting. What they offer is the full spectrum of fittings and you should be able to see them for yourself. 43 series fits many hose mainly 2 wire, 71 - 4 wire and 73 - 6 wire. May be more info than you wanted, but fluid and hoses cost too much to be wasting.
JIS is Japanese Industrial Standard it covers a lot of different fittings, bolts, O-rings etc. not just one type of fitting like our SAE sizes. As far as flange type fittings . SAE CODE 61, DIN Form R, and JIS Type I couplings are interchangeable except for clamp bolt sizes. SAE CODE 62, DIN Form S, and JIS Type II the same. Bad Bob
Bluox, I have looked online a little to find the specs you gave above. Can you tell me where you have seen them? I just want to make sure I don't have misinformation stored in my brain - there is enough junk in there, so I try to clean out the stuff I don't need from time to time.
I found some information to answer my own question on a pdf from a company called alphagomma, where they say about the same thing you said. However, I would still like to say a few things regarding hydrualic fittings. I don't doubt that the code 61 flange fitting meet the JIS specs regarding pressure and other engineering data that seems to be JIS 8363. I understand that written specification made up by the Japanese Indutrial Standard(JIS), Society of Automotive Engineers(SAE), Joint Industry Council,(JIC), or the Deutsches Institut für Normung (DIN) can be the same in meaning and requirements. But to say that they are the same when it comes to hydrualic fittings is misleading. If you walk into a hydrualic shop, lets say a Gates factory or a Parker engineering office, and say that you want to look at a JIS fitting- I am pretty sure they will go to the one fitting that looks like a JIC but has 30 degree angles and different threads - not a flange. I am not trying to say I am right, therefor you are wrong. I just think that the information the readers HERE are going see, regarding hose ends on a Komatsu machine, needs to be a little more simplified. I have looked on every major fitting company's website and have found none of them that referr to a Code 61 flange fitting as a JIS fitting. Respectfully,