Gradall 534D-10 crank no start

Since the umbrella seals and lift pump were already the known failure points and got replaced, and it fired right up after sitting overnight only to fail again, this points to a secondary air-ingress path you haven't hit yet, not a repeat of the same failure.

Most likely: the fuel filter water-drain valve not sealing. A reply on your own thread flagged this exact pattern on other Deere 4045 machines: on 2 deere engines the water drain on the fuel filter wouldn't seal 100%, showing no visible leaks but going airbound if sat for a couple days until the drains were cranked tight before breaking. Pull both filter housings, check the drain valves at the base, and torque them down hard (don't just snug them).

Second, the suction side upstream of everything you touched: cracked plastic tank pickup tube or dry-rotted rubber line from tank to first filter. Field reports on this engine describe the same "starts, sits, won't restart" cycle traced to dry rotted fuel lines from the tank to the filters that deteriorate and allow fuel to drain back, and separately to a plastic pickup tube in the tank cracking, sucking air along with the fuel.

Third, don't rule out electrical this time. A closely related 544D-10 with an intermittent crank-no-start traced to an inline glass fuse holder in the harness near the ECU that rattles apart and causes a no fuel/no start, later swapped to a spade-type holder. If fuel checks come back clean, wiggle-test that holder and check for voltage at the shutoff solenoid during crank.

Check sequence: crack a filter drain and retighten by hand-tight-plus-quarter-turn, pressure-test the low side with a hand primer while watching for bubbles at each fitting, then visually inspect the tank pickup line. If all that's clean, move to the fuse holder and solenoid wiring.

Sources:

• Gradall 534D-10 crank no start | Heavy Equipment Forums
• john deere 6415 starts hard - TractorByNet
• 2008 Gradall 544D-10 (Deere 4045HF275) Crank no start | Heavy Equipment Forums