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?
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.
not sure about the cats, but our Volvos have to have their systems recharged now and then
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.
Still no luck after adding fluid which in fact was low. How do the accumulators get charged?
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.
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
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.
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.
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?
Yup. No more than 5 seconds at a time, and it shouldn't require more than 3 times.
deadheading the pump did not work.
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?
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?
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.
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
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.
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.
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.
I powered them down yesterday and did that, I will have to try it tomorrow now that I have power there, the float function does work. Beats me, we’ve been trying to figure it out for 2-3 days now with no luck.
I think you can do it, maybe not exactly the way the book says (which uses ET) but it ought to work. The test in the manual for the Ride Control Accumulator involves powering up the Ride Control solenoid - Post #16 on previous page. Exactly as I suggested back then, and with the engine stopped, apply battery voltage to Pin A (wire # A520 Blue). That will pull in the relay and energize the solenoid. Make sure that happens, then do the following: - 1. Start the engine. 2. Raise the bucket about half-way. Tilt the bucket as far forward as it will go. 3. Lower the bucket to the ground. Continue to apply downward pressure. Try to lift the front wheels off the ground. 4. If the accumulator is charged correctly the front wheels will not lift off the ground.
That worked. The wheels did not lift off the ground when we applied power to pin A at conn 53 plugged in. With it unplugged it did not work. How do i test the pressure switch? I’m starting to think it is malfunctioning but it is sending signal when the machine is in motion.
The spec is on that electrical schematic I sent to you. Normally closed switch. Opens @ 32.6psi MAX with rising pressure. Closes @ 29.7±2.9 psi with falling pressure. You may have to get a bit creative about how you test it.
still scratching my head on the switch because testing it is difficult without pressure however. I energized 976 OR at the relay and have power at 976 OR at the pressure switch. I also have power at the blue wire at the pressure switch at the same time. I should only have a signal through the blue wire when the switch is open with pressure correct?
Power comes down wire 976 OR from the Relay (when the relay is pulled in as per signal from the ECM) located in the fuse box. 976 OR also supplies power to Terminal 1 of the Ride Control Relay located by the solenoid valve. The Pressure Switch is normally closed (opens with rising pressure) so you should have power on wire A520 BU all the time the switch is closed, in which case it will not be energized. A520 BU from the pressure switch is also the signal wire for the operating coil of the relay (terminal 5) - the other side of the operating coil (terminal 2) is grounded. So when A520 is energized the relay is pulled in. Effectively as soon as the pressure rises and opens the switch the Relay should deactivate . How are you testing the system.? Engine off or engine running.?
Key on engine off. We do not have power all the time at the blue wire with key on engine off not engine running. Should it only have power when ride control is active or at all times? Per schematic it seems it should be powered at all times. I energized the relay manually with the machine running and the booms drops to position as if the accumulators are charged and working properly. I believe I have. Working issue with the blue wire if it should be powered all the time
I don’t have the schematic in front of me but working from memory the relay in the fuse box should energize with the key on AND a Ride Control signal from the ECM. Key on supplies system power to the relay, the signal from the ECM energizes the coil and pulls the relay in. If the above happens, wire 976 will be energized. The pressure switch is normally closed so with engine stopped and power on 976 OR, A520 BU will also be energized which will pull the 2nd relay in. As soon as the pressure rises the pressure switch will open and the contacts of the 2nd relay should also open because it has lost the power to the coil that was supplied by wire A520. If you have a DMM put it across the terminals of the pressure switch with the engine stopped and check the continuity. It should measure close to zero ohms. Then start the engine and do the same test. This time it should be open circuit indicating that rising pressure has opened the switch.
ok so here's where I'm at... key on engine off - no power at 976OR and A520BU at pressure switch before signal from ecm? PRIOR to the relay being energized via signal from ecm should I have power at A520BU at pressure switch? -Engine running, machine in motion, FUSE BOX relay pulls in and 976OR is energized, 976OR signal present at pressure switch. A520BU energizes and second relay clicks and sends power to solenoid valve. the system began working after replacing the relays, suppressor however it only works when the boom is bottomed out not if is raised at all and provides no damping. it raises it a few inches but again, provide no damping.
Based on those symptoms I think you need someone with nitrogen charging tooling to check the pre-charge pressure in the Ride Control accumulator.