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304c

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    Boom Cylinder Extends But Will Not Retract

    Cat 304CR (NAD00987) I've got a boom cylinder that will extend but will not retract. In other words, boom goes up but won't come down. When I try to boom down, I hear noise from the relief valve, but the cylinder only moves about 1/4". I don't have a way to test flow, but I have adequate...
    • Howey Matt
    • Thread
    • 304 304c 304cr boom boom cylinder cat caterpillar cylinder excavator relief valve
    • Replies: 34
    • Forum: Compact Excavators
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    How to Determine Spool Orientation in Hydraulic Valve (Rebuilding Main Control Valve)

    I'm rebuilding the main control valve in my Cat 304CR (NAD00987) and I'm having trouble determining which way to install the spools. Some of the spools look like they're the same on each end -- others are clearly meant to be installed in a particular orientation. All of the spools have a...
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    How to bleed air from hydraulic system? - CAT 304

    Hi all, I'm starting a new thread for this issue. The original issue resulted in me removing the main control valve, cleaning it up, and installing new seals: https://www.heavyequipmentforums.com/threads/final-drive-motor-on-one-side-bogging-down-engine-cat-304cr.95940/ It's a 2004 Cat 304cr...
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    Final Drive Motor on One Side Bogging Down Engine - Cat 304cr

    I just replaced both final drives on this machine. It solved my issue on one side (caused by a failed final drive) but I'm still having a problem with the other side. Basically, when I engage the final drive on that side, the engine bogs down and the hydraulic pump whines like it's under...
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    Where to Buy Hydraulic Thumb?

    I've been looking for a hydraulic thumb for my Cat 304c. I want the pin-mounted type, not a weld-on. I've exhausted Google search and haven't found anything, new or used. Does anyone have a source for hydraulic thumbs?
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