Trailer brake question

Did you try putting just a very small bit of pedal pressure, then pull the trolley?

 

I'd suspect the air valve for the spike or the 2 way check valve that seperates the spike from the pedal.

I'd start with plumbing in a gauge on the inlet and outlet line at the spike and see what you're getting in vs out for pressure.

 

When I bought my 2021 567 the jakes would not come on unless I had the brake pedal slightly depressed. I had my local laptop guru change the settings and it works as it should now.
Basically "they" are trying to protect us from ourselves. Your truck is new enough I wonder if they made this the case so you cant use the trailer brake when parking for a few seconds. We used to do that as in the old days it took several seconds for the park brake to release, but only a fraction of a second for the trailer brakes to release if we used it for parking for short periods. Of course you can see where that may go wrong, and the consequences.

 

The Jake selection is callled” latched “and it’s just a parameter change. The setting has always been available on most all engines even back to CATs

I prefer them set this way. Hate turning the dash switch on and off constantly. Very little pedal application makes them come on.

 

I used to like it when the dash switch was too far to reach. Then ya just have to leave'm on.

Do you remember the old floor switch usually to the left of the clutch?

 

I miss days when making adjustments were much easier, and didn’t need a computer…..

 

I..yep.....themz wuz the dayz. Then you know exactly where the issue is. But, I have to say I don't ever want to go without my smart phone or www again.