Ineffective air brakes

An NHTSA Preliminary Evaluation into Chevrolet vehicles. Closed 16 October 1986.

Investigation
PE86073
Type
Preliminary Evaluation
Opened
13 August 1986
Closed
16 October 1986

What NHTSA investigated

Summary of information from manufacturer:none at this time.analysis:a pneumatic balance test performed on four of the subject busesby aftermarket brake system distributor indicated that during a 15 psibrake application, there would be 15 PSI at the front axle and 0 PSI atthe rear.one of the keys to brake balance is brake actuation and release.the rear should apply before the front and release slightly after.sincemost braking occurs below 20 PSI, it would seem that having the same orclose pressure in all chambers is important for proper balance.proposed action:open a pe.send an ir.

Vehicles covered

MakeModelModel years
ChevroletB6P1984–1986
GMCB6P1984–1986

Source

From NHTSA’s investigation file, rebuilt daily. To report a problem with your own vehicle, go to nhtsa.gov/report-a-safety-problem. All open investigations.