I was wondering if anyone happens to have a picture of the brake system hydraulic schematic for a L250G. Ours is throwing a low pressure warning on the screen. I've plugged a gauge into the appropriate test ports and it seems like all of our deliveries, charge, and cutout pressures are good. The accumulator pressures are good as well. I'm pretty certain at this point we just have a sensor stuck out of range. The big issue is we don't have a service manual on hand for this machine. We have the parts book and I can order one, but that'll take a few weeks to get to us and that doesn't do much good for an issue we have right now. Between the parts book and the system information from our L220E I've been able to fake my way through it, but I'd like to be sure I'm not missing anything. 2013 Volvo L250G VCEL250GP00003191
I think your looking at brakes and it's complaining about axle cooling. Have you serviced the axle cooling filters?
What exactly does the display show as an error?
All that comes up on the display is a full screen "Brake Pressure Low" warning. The warning can not be cleared to check anything else via the screen when the machine is running. It comes up immediately upon starting the machine and does not go away even when the main hydraulics are being worked. The brakes do function and we have not noted the machine to be overheating. I'm not against throwing a new set of filters on for the axle cooling circuit, but I don't have any on hand right now and would need to get a few on order. Can I ask what your reasoning is behind suspecting the cooler circuit is?
Ok, to enter service mode, key on, engine off. Press and hold the wrench button on the keypad. The screen will say enter service mode. Pressure the enter key. Now there should be a wrench icon on the display somewhere. Press the axle button. This should give you brake pressure in the accumulators. That Pressure, when running , should be between 1780 and 2210 psi. When brake charging is satisfied, you should hover around 21-2200 psi until you step on the brakes. The next thing to do is curl the bucket over relief, the pressure should rise to approximately 2350 or so. That is your Max brake charging pressure. Let's see where you shake out.
I would love to put the machine into service mode and check the displayed pressures, but this loader simply will not go into service mode. I am unsure if it was disabled by the previous owners or if it requires a different input, but holding the service button on the key pad with key on engine off does nothing but pull up the Service Menu. The only options there are the service reset and the automated test functions (lamp test and brake wear). I hooked our Diesel Laptop up to is and couldn't view any live sensor data, or at least not any that is important to the issue at hand. I connected a tetragauge to the test fitting on the accumulator manifold and verified we did have system pressure. At that time I also had someone pump the brakes and checked for system cut in and cut out. We even shut down and pumped the brakes down to make sure the accumulators were holding pressure. I don't have all the reading written down and its been a week or so, so I have forgotten them, but I am reasonably sure we were a lot closer to 3000 psi on the measurements we had under working pressure. If you know of any alternate ways to activate Service Mode I'd love to know, because this is the only loader we have that doesn't respond to the key being held.
Try pressing the wrench button with key off and then key on while holding the button. You should also be able to press the envelope button and get a list of errors recorded but with less detail.