M59, BT1200 issue

[Wayne Burkhart]

Dipper cylinder won’t retract

 

[fried1765]

Dipper cylinder won’t retract

I don't have an answer, but will be watching for the results, since I have the same machine

 

[Wayne Burkhart]

Should have added that all operations work except for the dipper cylinder extension. The valve moves freely, and cylinder can be extended by dragging with valve opened. Can’t decide whether it’s a valve problem or massive one way cylinder leak.

Note that this not my L48 but my former employer’s M59 with the Bt1200 hoe.

 

[TheOldHokie]

Should have added that all operations work except for the dipper cylinder extension. The valve moves freely, and cylinder can be extended by dragging with valve opened. Can’t decide whether it’s a valve problem or massive one way cylinder leak.

Note that this not my L48 but my former employer’s M59 with the Bt1200 hoe.

The cylinder will extend even witj a "massive" leak. Disconnect the hose and use a gauge to test the pressure going to the cylinder.

https://www.amazon.com/dp/B0087UYSPS

Sounds like yet another port relief problem.

Dan

 

[Smokeydog]

My M59 boom does that too and sometimes left swing as well. Usually after not using in a while. Suspect stuck relief valve? Debris or air? Fortunately a transient problem that goes away after operating. Going to take apart and clean valve someday.

Replaced the BT1200 quick disconnects and found someone or original assembly had used Teflon tape on hose threads. Usually a bad practice on hydraulic systems. Maybe a piece of tape got in the system? Others have experience similar problems with no definitive solution.

 

[mikester]

Start by checking your directional valves are all the way in, re-seat you QC hoses