Hello all. My 425, which has been working flawlessly for me since I purchased it several years ago, (with the exception of the breaker issue covered in another post) stopped working the other day. Ironically I had parked it in front of my barn to grease everything and now its inop It starts and the blade raises and lowers, but no other hydraulics. Usually I get things functional by lowering the left console, and now nada. Any thoughts so far? I have looked at the service manual and there is a switch (maybe 2 which is one of the questions I have) that activates the hydraulic system. However when I put the left console down the hydraulic light illuminates on the panel, which to me would mean that the switch is closing. Could there be 2 switches? I looked at the schematic and it is confusing as the switch(es) have different names. Before I start drilling out screws to access the guts of the console I thought I'd ask you folks. This excavator is in Hawaii and even though I keep it out of the weather that hasn't been the case for it's previous life. I checked the fuses and they all seem good. This machine is crucial to my life here on the farm, as I am constantly clearing and moving material. Any help and ideas would be much appreciated. Mahalo!
Thanks for sharing your issue — this is actually a fairly common problem when using hydraulic breakers like the Bobcat 680 on excavators not configured with a proper "return-to-tank" (free flow return) line. Based on your description, here are some likely causes and suggested solutions: --- Possible Causes 1. The return line is not connected directly to the tank Hydraulic breakers are sensitive to backpressure on the return side. If your return hose goes through a control valve or manifold instead of directly to the tank, residual pressure can force oil out of the fitting, even when the system is off. 2. There’s a check valve or flow restrictor on the return line Some excavators are set up with restrictions on the return for attachments like thumbs or grapples, which are incompatible with breakers. Any resistance here can cause leaks and damage to the breaker. 3. Quick couplers not rated for breaker use Even if your hoses are new, old or mismatched quick couplers (especially ball-type or low-flow ones) can leak or restrict flow. Flat-face high-flow couplers are preferred. 4. Trapped residual pressure in the return If the return line retains pressure even after the auxiliary circuit is turned off, this may explain why you're seeing continuous dripping. It can happen due to the valve block configuration or lack of pressure relief. --- ✅ Recommended Fixes Verify that the return line goes directly to the tank, not through the valve block. If not, consider modifying the system to provide a dedicated low-resistance return-to-tank port. Replace the quick couplers with flat-face, high-flow couplers rated for breaker use. Temporarily disconnect the breaker, activate the auxiliary controls briefly to release trapped pressure, then reconnect to see if the leak stops. If so, it's a sign of pressure retention. Avoid operating the breaker with a restricted return line — it can quickly destroy the internal components of the breaker. --- If you can share the hydraulic diagram or photos of the return line routing, I’d be happy to help you further troubleshoot. Best of luck — I know how tough lava rock can be!
Hey thanks for the reply on the breaker issue! Do you have any feedback on the current problem noted above regarding the hydraulics in general? I'm dead in the water with this and don't want to just dig into stuff without a reasonable plan. Mahalo!