Narrative:

Picked up aircraft from maintenance a doc 10 was performed plus the right landing gear strut was replaced. Noticed a non-normal anti-skid test (light did not blink but came on steady during test) started engines and taxied normal with normal brakes. As we were approaching the end of taxiway a and ready to hold short of runway 11 PF(pilot flying) said I have no brakes.....I immediately got on the brakes and found we had hard peddles or pressure but no slowing of the airplane was noticed. I made a radio call to the tower that we had no brakes and were going to turn onto taxiway A2 and onto the runway. PF could not make the hard turn without brakes and I told him to put it on the grass and that would stop us.....which it did. We still had the pneumatic braking system but we were going so slow by that point we did not use it; but because we knew we did have that system if needed; we decided to exit the grass and taxi back to the ramp where maintenance was. Brakes were working again and 'appeared normal' but we were taxiing very slowly. The tower asked if we were going to taxi back to the ramp in that condition. We did not take the time to explain that we still had a backup system with the pneumatic brakes; and stated yes we are taxiing very slowly. Tower said roger 'taxi at your own risk' PF applied brakes again and stated no brakes again; then they grabbed and we had brakes.....this was extremely confusing and I told [pilot] it is not a brake problem it is an anti-skid problem. We got to the ramp; parked and shut down the airplane. When maintenance took the wheel hub off the right main landing gear they noticed the 'anti-skid cannon plug' fell off when he touched it. It was barely on or connected; if at all screwed on. We now knew what the issue was.

Related reports:

Google
 

Original NASA ASRS Text

Title: Flight Crew flying CJ525 aircraft encountered loss of braking while taxiing for takeoff.

Narrative: Picked up aircraft from Maintenance a Doc 10 was performed plus the right landing gear strut was replaced. Noticed a non-normal anti-skid test (light did not blink but came on steady during test) started engines and taxied normal with normal brakes. As we were approaching the end of taxiway A and ready to hold short of Runway 11 PF(Pilot Flying) said I have no brakes.....I immediately got on the brakes and found we had hard peddles or pressure but no slowing of the airplane was noticed. I made a radio call to the Tower that we had no brakes and were going to turn onto taxiway A2 and onto the runway. PF could not make the hard turn without brakes and I told him to put it on the grass and that would stop us.....which it did. We still had the pneumatic braking system but we were going so slow by that point we did not use it; but because we knew we did have that system if needed; we decided to exit the grass and taxi back to the ramp where Maintenance was. Brakes were working again and 'appeared normal' but we were taxiing very slowly. The Tower asked if we were going to taxi back to the ramp in that condition. We did not take the time to explain that we still had a backup system with the pneumatic brakes; and stated yes we are taxiing very slowly. Tower said roger 'taxi at your own risk' PF applied brakes again and stated no brakes again; then they grabbed and we had brakes.....this was extremely confusing and I told [Pilot] it is not a brake problem it is an anti-skid problem. We got to the ramp; parked and shut down the airplane. When Maintenance took the wheel hub off the right main landing gear they noticed the 'anti-skid cannon plug' fell off when he touched it. It was barely on or connected; if at all screwed on. We now knew what the issue was.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.