CAT 930H RIDE CONTROL NOT WORKING

[Fairfieldcounty]

Hi guys,

I have a 2007 cat 930h and the ride control has stopped working. it worked perfectly prior to changing a few hydraulic lines for the tilt cylinders. I added fluid but is it possible to not work due to fluid being low? I plan to add more tomorrow but it appears to be nearly full.. I have checked the fuses and the relays appear to be working. the light illuminates on the cluster when the machine gets up to speed.
SERIAL # CAT930HPDHC00270

what's my next step in troubleshooting?

 

[512high]

Not sure regarding fluid, being too low, possible, and if I understand correctly ride control uses the cylinders in the front to dampen the ride, also goes I "think" to nitrogen or actuators? Sorry I'm sure I messed that up! Lots of good people here, they will chime in.

 

[cuttin edge]

not sure about the cats, but our Volvos have to have their systems recharged now and then

 

[heymccall]

To charge my Deeres ride control hydraulic circuit after cylinder hose replacement, the boom needs raised to the sky and stalled on relief several times.

 

[Fairfieldcounty]

Still no luck after adding fluid which in fact was low. How do the accumulators get charged?

 

[512high]

Good question,,,,not sure if that has to be done a the dealership?

 

[Nige]

Good question,,,,not sure if that has to be done a the dealership?

Not necesarily if you know a mechanic/technician with a nitrogen charging kit.

 

[512high]

Nige, Is correct, a friend of mine had is Caterpillar 924G I believe same issue the cat dealership state of the art facility that opened up near us a few years ago I believe he actually took them down there and they re-charged him, but I guess any independent mechanic that has the capabilities at a lower price I would assume

 

[heymccall]

If it worked before hose failure, then the accumulator isn't suspect.
You have to load, charge, pressurize, whatever you want to call it, against the accumulator with hydraulic oil at high pressure. This is achieved by raising the boom completely and hold it on relief for several seconds. Repeat if necessary.

If the nitrogen "fell" out of the accumulator, odds are that it wasn't from the hose failure, and, odds are that it won't hold a new nitrogen charge.
The nitrogen never touches the oil, and is captive inside the accumulator.
There are seals within the accumulator and a shraeder valve on the end for charging.

 

[Mobiltech]

Should be 2 accumulators under the step if i looked it up right.

The solenoid on the side of them should be powered up in manual mode or when your up to speed in auto mode.

 

[Fairfieldcounty]

I spotted the accumulators today on my way out of the shop by tracing the hydraulic line to them. This machine does not have a manual ride control. It is auto or off. I will have to figure a way to check the solenoid tomorrow. What do you mean by holding it at relief? hold the joystick in the raise position like I'm deadheading the pump?

 

[heymccall]

What do you mean by holding it at relief? hold the joystick in the raise position like I'm deadheading the pump?

Yup. No more than 5 seconds at a time, and it shouldn't require more than 3 times.

 

[Fairfieldcounty]

deadheading the pump did not work.

 

[Fairfieldcounty]

I have checked the solenoid on the accumulators and it was working properly. I have checked the relay there also and it appears to be working properly, showing no resistance. the relay in the fusebox appears to be working properly also, I plan to double check that tomorrow with my power probe. There is one connector that looks like it has a fuse molded into it that I was unaware of how to check. Any one know how to verify the valve inside the accumulator mount/block is working properly? where else do I look?

 

[Fairfieldcounty]

Checked the valve and it works properly. How do I energize the valve from the fuse box with the machine off key on? It’s an automatic ride control switch. Is there another way to turn it on manually?

 

[Nige]

There is one connector that looks like it has a fuse molded into it that I was unaware of how to check. Any one know how to verify the valve inside the accumulator mount/block is working properly? where else do I look?

Would you like to post a photo so that we can see what you're talking about. It's not the connector with the 106-8704 Arc Suppression Diode (shown bottom right inside the blue rectangle) in it is it..?
I sent you the electrical schematic. Did you get it.?
Apply 24V+ to Pin C of CONN 53 while the wiring harness remains connected and the key switch is ON. You need the CONN 53 to remain connected because the outbound power from the relay uses wire 976-OR that is Pin A in the same connector. That ought to energize the Ride Control Valve Relay.



BTW the NOTE E in parentheses at the bottom means that it for 930H machines only, meaning that it is applicable to your machine.

 

[Fairfieldcounty]

Would you like to post a photo so that we can see what you're talking about. It's not the connector with the 106-8704 Arc Suppression Diode (shown bottom right inside the blue rectangle) in it is it..?
I sent you the electrical schematic. Did you get it.?
Apply 24V+ to Pin C of CONN 53 while the wiring harness remains connected and the key switch is ON. You need the CONN 53 to remain connected because the outbound power from the relay uses wire 976-OR that is Pin A in the same connector. That ought to energize the Ride Control Valve Relay.

View attachment 208657

BTW the NOTE E in parentheses at the bottom means that it for 930H machines only, meaning that it is applicable to your machine.

I got the schematic thank you. I applied power to the relay and it clicked, however it is not sending power to the solenoid. We will be replacing it tomorrow. We have bench tested the solenoid valve and it works on the bench. We tried applying power directly to the solenoid while driving via power probe and it did not work, not sure if the rest of the system needs other components activated by the relay energized for the system to work properly.
We applied power to CONN 53 pin C and the solenoid clicked but did not have power at the green wire at the solenoid valve.
We energized wire 976 OR at the fuse panel and had power to the relay and CONN 53 but not the solenoid. All connections are good and no open circuits or shorts. Hoping that relay solves our issue but I am not confident at this point

 

[Nige]

If you energized wire A976 and had power at CONN 53 and the solenoid did not operate my first thought would be that either the Ride Control relay is bad or you have a wiring problem in between the relay and the solenoid.

Don't lose sight of the function of the Arc Suppression Diode as discussed before. If that is malfunctioning then all kinds of weird things can happen.

 

[Fairfieldcounty]

Update... I now have power at the solenoid. I found the pressure switch on the right ladder side to be unplugged. However the ride control still does not work. I have +\- 27 volts at the green wire while the ride control is active and the machine is in motion. The boom still doe not float. What is my next step? All the electrical is intact and working as it appears it should. How can I check the accumulators for pressure? I also raise the bucket To the top and held at stall for 5 seconds 3x and repeat 2x previous to travel.

 

[Nige]

Might be a stupid suggestion but try powering the lift cylinders down and holding the hydraulic system at relief for a few seconds. It will lift the front wheels off the ground but otherwise it’s safer to do than raising because it puts less stress on the cylinder head bolts.

Regarding the ride control accumulator I’d need to take a look how you could possibly test the nitrogen precharge without putting gauges on it.