John deere air brakes slow to realease

[cla2170]

Got a 6190r, taking ages to let air brakes off on trailer. Unscrewed the male coupling and only a trickle of air coming from it. Just wandered if its anything to do with air brake control valve on left hand side beside wheel? Took wheel off but still very awkward to get to with diesel tank blocking access. Any one had any like this? Thanks in advance!

 

[davidroberts30]

Got a 6190r, taking ages to let air brakes off on trailer. Unscrewed the male coupling and only a trickle of air coming from it. Just wandered if its anything to do with air brake control valve on left hand side beside wheel? Took wheel off but still very awkward to get to with diesel tank blocking access. Any one had any like this? Thanks in advance!

Same with handbrake as foot brake?

 

[cla2170]

Same with handbrake as foot brake?

Yea just the same

 

[MontyK]

Have you changed the air dryer canister ? Used to have brakes stuck on hgv, little popet valve comes apart in filter housing that used to cause symptoms.

 

[Captain Sensible]

Got a 6190r, taking ages to let air brakes off on trailer. Unscrewed the male coupling and only a trickle of air coming from it. Just wandered if its anything to do with air brake control valve on left hand side beside wheel? Took wheel off but still very awkward to get to with diesel tank blocking access. Any one had any like this? Thanks in advance!

Do the trailer brakes come on quickly/properly when you drop/disconnect the Red 'Supply' Line?
If so, put a T-piece in-between the tractor's Yellow 'Control' line coupling & the trailer coupling & attach a 0-10 bar pressure gauge to it. See how quickly the Yellow line pressure drops when you release the brakes.

If it's slow then the problem's in the Tractor-Trailer Brake Control Valve ...... If it's not slow, the problem lies with either the Trailer's Relay Valve or the trailer's Line Filter in the Yellow line ..... partially-blocked.