[Hacke]

Thank you FredM. I looked at the download and as I've heard the DB 3 point is a complicated system, and I agree, it looks very hard to understand. Not sure where I'm going from here. Hopefully someone will chime in with some ideas where I should start and what to check for.

I uploaded an Operator's Manual for 990-995 to the Resource Manager section. Section 2 is about operating the Selectamatic system, it should be the same instructions for your 880:

https://www.tractorforum.com/attachments/david-brown_990-995_manual_sec_wat-pdf.93868/

I know nothing about this system, but read some now. The Lift Latch is normally for locking the three-point lift in its upper position, but it is incorporated when you prepare the system for Depth, Height or TCU control. If I got it right, your latch is in engaged position. I do not know if that make a difference, but it make more sense to have it in disengaged position under normal use. Just a thought.

The three-way valve should not be necessary since you have the double-acting control valve. I do not see it in your pictures, but perhaps you have the three-way valve as well. If that is set to operate external hydraulics only, the lift will not work.

 

[Hacke]

Perhaps there is something useful here:

Selectamatic Hydraulic System — David Brown Tractor Club

www.dbtc.co.uk