JW-03 Still Broken

[RonMar]

I finally have the pressure gauge installed and working. I ran a quick test today and all the cylinders seemed to be operating below 2000psi cold, until I maxed out the cylinders and got that groaning sound, at which point the psi jumped to around 2300 - 2400. What kind of pressures should I be getting for the different cylinder operations? When I get some time later in the week Ill get full pressure readings, cold and hot, for each of the cylinders. Also, what RPM do you guys usually run it at? Thanks again for all your help!

While the cylinders are moving, you can see any pressure up to the relief pressure. That is just the pressure necessary to perform the work being done(cylinder/arm moving). The pressure you are interested in is the full relief pressure which is achieved when the cylinder stops moving(reaches an end stop or the earth stops it's travel) while the lever is held. Your description sounds prettymuch normal for pressures with the full relief operating in the 2300 PSI range. 16MPA = 2320PSI...

As for engine RPM, I run 1500-1800 typically. Any faster and the boom swing gets pretty twitchy. Those cylinders are pretty small compared to the rest of the BH and fill rather quickly even with the restricted orofices found on those working ports. They are also on a short lever arm which moves the boom quickly.

So what exactly is making noise on your BH when you fully extend/retract a cylinder? Is the noise comming from the valve block where the relief is located, or is it comming from the pump?

If it is comming from the pump, and you are game, I have a fairly easy test for you to try to see if it quiets the pump operation under full load/relief pressure. Basically you remove the rear cover of the control cabinet. Then you disconnect the banjo bolt fitting where the return line is connected to the top corner of the reservoir tank(screw bolt back into tank fitting). Pull that return line back up thru the BH frame so you have some slack available. Remove the reservoir filler cap and mesh screen filler funnel and put the return line down the filler pipe as far as possible. Then run the BH and max out the cylinders and see if it sounds any different under load...

AGAIN 16MPA = 2320 PSI, sorry for the earlier error...

 

[erj]

Just a small suggestion - secure the hose that you run down into the top of the tank just to be safe.
RonJ

 

[cv63usafsfs]

So I have good news and bad news. The good news is the vibration is gone. I isolated the noise down to the pump and were the hose from the pump connects to the valve block. Taking a closer look at the pump I noticed that when its running the output line gets pinched between the pump and the 3pt hitch, so I set the pump up upside down so that the line was no longer pinched. That did the trick.

Now the bad news. After a while of testing it by moving some dirt around, the pressure suddenly dropped. All of the cylinders maxed out at 500 psi and would barely move. Any ideas on the latest issue?

 

[jakell2010]

That doesn't address the o-ring issue,,did it shred again?

 

[Bob Rooks]

My guess: Since you don't have any filters in the hoe's hydraulic system, the pinched hose was damaged internally and bits of it stuck in the control and relief valves.

 

[RonMar]

Sounds like something stuck in the relief valve to me also, or another shredded O-ring...

What fluid are you using?

 

[cv63usafsfs]

That's what I was figured. Hopefully its just gunked up and not a shredded o-ring again. Once I find time I will take it apart yet again and see whats going on with it. Thanks again for your all your input.

 

[cv63usafsfs]

Finally got time to take it apart today. Turns out the o-ring shredded again and clogged up the rest of the valve. Any ideas on why it keeps doing this? What brand/type of o-rings do you guys use, maybe the ones I picked up are no good.

 

[Bob Rooks]

The spool could be travelling too far and catching an edge. Check and adjust the linkage or spool stops.
The O-rings should be Nitrile, Buna-N, polyurethane, or silicone. Plain rubber or neoprene don't hold up well at all in hydraulic service.

 

[cv63usafsfs]

Finally got time to take it apart today. Turns out the o-ring shredded again and clogged up the rest of the valve. Any ideas on why it keeps doing this? What brand/type of o-rings do you guys use, maybe the ones I picked up are no good.