Not shift into gear while engine is running, but shifts into every gear when engine is off.

[AMG33D]

Salutations, everyone!

A 2011 Mercedes Vito W639 RWD 2.1 Diesel is in my possession.

With the engine turned off, it shifts smoothly into any gear after I adjusted the cables, which were the Mercedes-specific parts, and the gear selector arms. I feel like I'm missing a clutch because the engine won't shift into any gear when I turn it on. A year ago, a new clutch kit called LUK (3 pieces) was introduced. After inspecting the clutch and bleeding it from the gearbox side, everything appears to be in good working order. I can quickly shift into first or second gear without crunching if I press down on the clutch pedal five to eight times. It starts up normally in any gear when the engine is off, and the clutch bites where it should, but as soon as I shift into neutral, the clutch becomes inoperable, as if it were defective. Has anyone else experienced this problem, and if so, what could be causing it? What lies ahead for me? Is it a clutch problem? I don't believe so. Is there a problem with the clutch operating? The clutch slave cylinder is new, so it could be the pedal cylinder. From the engine side fluid bottle to the brake pedal to underneath the gearbox side, I have not detected any fluid leaks anywhere in the system.

Your guidance is greatly appreciated.

My sincere appreciation

[dave783]

It seems like a clutch issue, either with the master or slave cylinder, even though you've bled the slave. Since you said that it engages after a few pumps of the pedal, I'd say it's either the master or the slave. Good luck!

[keithmerc220]

Is there any liquid present on the floor behind the clutch pedal? It may be beneficial to inspect behind the pedal to determine if it is damp.

[AMG33D]

I appreciate your response. I will attempt to replace the brake fluid and re-bleed the system.

[AMG33D]

I appreciate your response. Inspected the entire hydraulic line and found it completely dry. I suspect it may be an internal issue, possibly involving one of the cylinders, the clutch plate, or perhaps a bearing.

[dave783]

If it is the concentric bearing, a fluid leak should be observable at the base of the bell housing; thus, if it is dry, the issue pertains to the clutch, necessitating the removal of the gearbox for thorough inspection.

[ML350_Colin]

For what it's worth, it appears to me to be predominantly a clutch problem.
Engaging the clutch pedal yields a marginal impact, which strongly indicates a hydraulic issue (potentially sparing you the time and effort of gearbox removal).
Have you inspected the slave cylinder, which is relatively accessible compared to the gearbox?

[DSM10000]

This exhibits all the indications of residual air in the system; what method are you employing to bleed it?