An FMVSS 121 compliant air brake system is supposed to be regulated to where the cutoff pressure is between 115 and 135 PSI and the cut-in pressure is no more than 20 psi below the cut-out pressure. The absolute minimum cut-in pressure for buses is 85 psi, and for trucks it's 100 psi.. otherwise, the air governor needs to be replaced.
60 psi is the hold off pressure for a spring brake system, while brake emergency chambers are governed at 90 psi.
Generally adjusted for 125 psi but they also have a blow-off valve that releases anything over 150 psi for safety purposes.
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An FMVSS 121 compliant air brake system is supposed to be regulated to where the cutoff pressure is between 115 and 135 PSI and the cut-in pressure is no more than 20 psi below the cut-out pressure. The absolute minimum cut-in pressure for buses is 85 psi, and for trucks it's 100 psi.. otherwise, the air governor needs to be replaced.
60 psi is the hold off pressure for a spring brake system, while brake emergency chambers are governed at 90 psi.
Generally adjusted for 125 psi but they also have a blow-off valve that releases anything over 150 psi for safety purposes.
If part of the cargo is unloaded, the remaining cargo should be moved to