So Ive recently picked up the below pictured excavator, UH10LC and would like to know what the pump pressure should be along with how to check and adjust pressure. Pumps are HPV125A's. While working on it today I noticed that there seems to be a dipstick or what looks like a dipstick on the swing motor, when I pulled it out there was no oil, the end of the stick had a funny stepped end? I welcome any info.
Also anyone have an idea of cooling system capacity?
It sounds like you need manuals for the machine. Without them, you might overlook important maintenance information and make very expensive errors. Deere sells Hitachi manuals on their website that one can download and print, but I'm not sure if they have them for your model. That dipstick on the swing motor likely checks the gear oil in that unit. It likely takes 80-90 weight gear oil - at least that's the case on my slightly newer Hitachi excavator. Higher up on the swing motor you may find a plug with a square head; remove that to add oil to the unit. Good luck with this!
Here's a link to manuals if you're interested. They appear to have manuals for your machine. http://www.johndeeretechinfo.com/index.cfm?event=home&menuDivision=HITACHI
Ordered parts manual today, no service manual available from Deere.
Going from memory! The main pressures should be 250 bar or 3675 psi. I cant remember if the travel pressures are more but the boom arm and bucket should be at that pressure. The swing may also be lower. The thumb pressure should be low enough that the bucket can push it back. Takes some playing to get that right. The dipstick, actually a metal rod with a step on it is your gear reduction level. Should be full of 80w/90 gear oil. If there is none then the reduction seal could be leaking. Don't run it without oil! Or $$$. Check the underside of the tool box lid for the qty of coolant and all other levels. To check the pump pressures you have to put in a test port or fitting in the block where your pressure hoses come out of the pump. On the back side there should be a plug. This plug is British Standard Pipe Parallell or BSPP size I believe is #4. Or drill and tap the plug and install what you need. Drain the hydraulic tank air pressure first as this machine uses a compressor to charge the hydraulic tank. In the picture of the pumps there are 2 metal rods coming from the valve banks to stroke the pumps. If these are not going all the way then the machine will be slow. The ramps and rods wear out and then they do not pull the stroking rods all the way. The easiest fix is to pull off the rod assy where it bolts to the valve bank die grind those holes and set the rod assy as deep into the spool "V" . I will try to see if I can find the pressures. Good luck
The thumb has a pressure bypass besides the one in valve body and is easily overcome by bucket, still plenty of pressure to sqeeze the water out of trees.
I just found an old spec sheet. One Bar = 14.7 psi. The main reliefs (1 for each valve bank) are 250 Bar. That would be for the boom, arm ,bucket and travel.The port reliefs are all 265 Bar. The swing motor is 190 Bar set at the motor. One relief for each direction. Got your reply on the thumb. That sounds good.
So can I dead head the output from the valves to adjust pressure? Not sure I can figure out in my head how to check main reliefs? When checking pump pressure does it have to be under load or operating? Any more spec sheets? I have fax # Thanks a bunch
When checking pressure. We will do boom up. Full RPM pull the function gently untill the boom cannot go any further then pull the function all the way. Then set the pressure on the main relief whlie still pulling the boom up function. (2 People). keep in mind the boom and the arm use a spool out of both valve banks so you have 2 main pressure reliefs set at the same pressure. It is easier to see it done than to explain here. If you know someone that can do it, have them show you. First thing first, check the pressures if they are good. No need to adjust.
That makes sense
Well, we have to be carefull, Ken. One ATMOSPHERE is close to 14.7, but one bar (barometric), is closer to 14.5 and change. Doesn't sound like much until we start talking diesel fuel pump or hydraulic system pressures.
I'll be using a guage that reads in bar
KenAl, Concering the rods that go to the pumps you mentioned they "stroke the pumps," does that mean they are a volume control and if so there must be an operating range for the levers on the pump to be set with in?
Yes your right 14.5. Hit the wrong key without looking back. Yikes. Yes the pumps are variable displacement. The rods are just your signal to the pumps on what you want. From there the pumps are internally regulated. There are pump adjustments. Stay away!! You can have those so far out of wack by srew turning. Hopefully they are set ok. The proper way to ADJUST the pumps is with a flow meter. Some will say you can do it with engine pull down but you will not find specs for that on a UH10 with I believe a Hino engine and most likely a bit tired. What I have done if by myself is to have the machine "shut off" and everything relaxed and on the ground. Tie the lever (eg Boom Up) back all the way then go back to the stroking levers and see if I can move them more. If so, then back to the rods and cams. The only function you can't do this with is the arm as it has a pilot assist valve under the cab and needs to be running. I forgot to mention that all the linkages can have wear also. I would pull the pins out and drill the holes out to fit an oversized std pin in. The way to check this is to see if with a pry bar you can pull/push the spool out more than with the lever tied back. Better to have someone in the cab moving the levers. Remember Shut OFF on the ground as this machine if the boom is in the air and shut off you push the lever for boom down and the boom will come down!
Thanks Ken, I manually pulled one of the rods the other day and could hear a change in the pump but it seems to me that they could be pulled farther than what the valves do, just did not want to run the chance of blowing something up. I plan on pulling the rod levers of the valve body to fix the holes that are slightly oblonged before performing any adjustment. The motor is a 6RB1 or E120, 260hp n/a and seems to be the best running part of this machine, starts every time with no glow plugs and sounds super smooth. From your experience just how did these machines run, power and speed. As for the power assist ive contemplated removing to get rid of some play, thought I might try to rig a temp. bar with vise grips to see just how heavy the pull is. It seems to me that either the main boom or bucket is also power assist. At some point someone changed some of the linkages and used clevis ends and they a now loose I ordered some heim joints today for replacement. I think once I get all the play out of the linkages this machine will be a pretty nice unit, not saying I'm going into business with it but the functions that pull the valves althe way open seem to move at a pretty good pace and the pins are pretty tight for an older machine.
Rebuilt pump levers today. I'm excited to re-install and get rods properly adjusted. Cooling system capacity ended up at 10 gal. I also rechecked the dipstick on the gear reduction for the swing motor and it does have oil it was just below the tip of the dip stick. I was also able to get the stubborn track to tension out. I had to loosen the nut and use a big pry bar to move ram back a little, I guess thats all it took as I was able to get it to push right out. Also did some wiring in cab, basically removed rats nest of wires. Cleaned up what was needed,stereo now works including the factory hitachi speaker. While I was working on it the other day I removed heater box and took it home with me, dissasembled and went off the the radiator store where I was able to find a replacement core so now the heater works without steaming up all the windows. Getting closer!
Iv been looking for a larger bucket for this machine and took a look at this guy today http://www.machinerytrader.com/listingsdetail/detail.aspx?OHID=7078307&dlr=1 looks to be a nice bucket but its 4" longer from pin center to teeth tips than my current bucket. I know i would have to replace the ears and was thinking of cutting the teeth off for a straight edge, what do you guys think?