600A Platform Swing not swinging

[DavidL]

When engine running, all hydraulics with exception of the platform swing work fine. When in the cage I push the swing Left or Right electric switch, I hear the engine load, but no movement at the platform. I pulled the three lines off and One line does have continuous flow, but not high volume. I see on the schematic that it is regulated flow to .2 gpm.

I can push the platform against a tree (with some hydraulic effort by other cylinders) and it does move.

I pulled the platform rotate solenoids off the main stack and fluid pours out of one port on the main block.
I applied 12 volts to both solenoids, and they both shuttle the valves back and forth (at the same time) so electrically they seem fine....

Any ideas? Possibly the platform motor is just too tight / bound up for the limited hydraulics to move? I hear the platform rotate isn't the strongest thing even on a good day... what's your experience?
Thanx.

 

[TheFixer]

I would pull the lines and cap them and put a pressure gauge on it. You need to see if you are truly getting pressure to the motor. The service manual should tell you the pressures and adjustment procedure. If you have pressure at the motor, then the motor is probably bad, internal leak. You can tell too if you hold the control and you hear oil flowing thru it. If you do that long enough, it may get warm. That indicates you have an internal leak.

 

[DavidL]

I forgot to add that when all three lines were disconnected to the hydraulic motor, and the gas motor running, when engaging the Right or Left switch, the gas engine loading sound is identical as to when the hydraulic motor is connected. Are the two lines supply lines to the hydraulic motor or returns? ie: there is fluid coming out of One line...not two. No matter what position the electric switch is in.
When connected, I don't see the lines flexing at all when toggling the electric switch back and forth.
The hydraulic schematic says .2 gpm and 50 psi. What gauge would be used for this?

It's almost like the fluid isn't getting pressure to the end of the hydraulic line. Wonder if I should find which lines attach to the main block and see if any are blocked...

 

[TheFixer]

I looked at the 600A service manual, and I don't see where the .2gpm and 50 psi comes from. In hydraulics, that's not even usable. There is a section 4.8 and 4.9 under the boom and platform that talk about bleeding, testing for internal leaks and pressures. They say it should be at 3000psi.

I don't see where the valve is or where to adjust.

I buy most of my hydraulic parts from surpluscenter.com. They have 5K psi gauges for $12. You need to buy the appropriate adapters and hoses. Buy a very long 1/4" hose like 15' if you can so you can monitor from the bucket.

 

[92U 3406]

I'd plug in the analyzer and try bumping up the the platform rotate speed first. I encounter this quite often where I'm at. Here its mainly because of climate. In winter its -35 and we need to jack up the speeds to actually have movement but in summer, the functions are too fast and need to be turned down. If you still have no movement with the speed turned up, I would start looking into hydraulic issues like the rotary actuator bypassing.

 

[DavidL]

Found the .2 / 50psi on page 7-56 sheet 1 of 4 of the hydraulic schematic. figure 7-55. Platform Rotate 9 (circle) .2gpm and 39 (circle) "set at 50psi"
I don't think this model / serial number has an analyzer plug / port. Don't have the tool either...that would make things easier if it did.

 

[TheFixer]

The service manual for the 600A shows the analyzer like the other guy says and does not have those pages in it.

What year is your machine?

 

[DavidL]

I think it's a 1999....serial: 0300040861
Manual: Service_3120718_09-23-05_ANSI_English.pdf

 

[DavidL]

Well, I was holding the switch to see if the fluid heated up the motor (demonstration of flow)...and low and behold - the platform swiveled. There is a 15 second delay before the platform moves....is that what a known good machine takes? I am ok with that as I don't use swivel that much.

 

[DavidL]

Thinking about this more...if there was air in the line...maybe that's a reason for the delay? If the fluid volume is truly limited to .2gpm...it could take a few seconds for the air to compress / motor to move. I am not hearing any pulsing / air bubble types of noises. It's just slow to respond. Haven't pushed on it, but it doesn't seem all that strong either. I have heard that is pretty typical.

If Air in the fluid....I assume that eventually would work itself out to the tank. I don't see any fluid drips anywhere.

A good hydraulic gauge would be helpful here...just need to confirm the 50psi (tiny) to buy the right gauge.

 

[92U 3406]

Function accel/deccel delay is also programmable through the Analyzer. I like to set them to no more than 2 seconds or so.

 

[TheFixer]

I guess you need to verify that it is or isn't programmable. Sometimes these functions have lockout valves so they don't move if you loose a line, maybe that is not working and the fluid is draining back. Maybe the fluid id draining out of the line thru the valve spool. After it operates, wait 10 seconds, does it take another 15 seconds to move? If so, you have some type of delay built in or programmable. If not, then probably the oil draining out of the line when it sits. Long hose to fill.

 

[DARO]

I had one with a kink in the hose in the cat track. Ran just like that.

 

[DARO]

Replaced hose to fix it. Those hoses are really flexible but dont hole up to hard corners/ kinks.

 

[DavidL]

The swing has been working, just with a long delay...I replaced another line and didn't notice any kinks in any other lines. I'll ignore this issue for now since it will work. Thanx for the feedback!