M816 Brake issue

[Mason098709]

Good afternoon,

The brakes on my M816 are continuing to lock up. When i come to a stop the brake pressure is not being relieved. I have to break open a bleeder valve to relieve the pressure. After reading threads from others with similar issues i have replaced all 6 wheel cylinders and the air pack, the previous owner broke the glad hand so there is no pressure there and it is not blocked with debris. After replacing the air pack it braked great for about 15 miles before the problem returned. Before installing the air pack i made sure to pull the square plug and add air tool oil. Thank you for yalls time and help!

 

[NDT]

Which glad hand? Front or rear? The front is which will cause this.

 

[Mason098709]

Which glad hand? Front or rear? The front is which will cause this.

Front passenger is the glad hand that is broken.

 

[NDT]

Make sure the front service gladhand cover has a vent and the line is not capped off.

 

[Mason098709]

Make sure the front service gladhand cover has a vent and the line is not capped off.

My front service glad hand is the one that is not capped off.

 

[Superthermal]

When I bought my M813 I had the same issue. I would drive and the breaks were fine, after using them one or twice they would start to bind... if I didn't use the breaks for a bit they would relax. One of my glad hands had been shut so the air couldn't escape/bleed off after the brakes were applied.