HEAVY TRUCK BRAKES MICHIGAN
MECHANIC STUDY GUIDE QUESTIONS
AND CORRECT ANSWERS
ANA2ENGINEA2BRAKEA2(JACOBSA2BRAKE)A2-A2Ans--A.A2ISA2AA2SELF-
ENERGIZINGA2SERVOA2TYPE.
B.A2ISA2NORMALLYA2USEDA2INA2PLACEA2OFA2AA2SPRINGA2BRAKE.
C.A2RESTRICTSA2THEA2INTAKEA2PORTA2ANDA2CAUSESA2AA2BUILDA2UPA2OFA230-
45A2LBSA2OFA2PRESSURE.
D.A2OPENSA2THEA2EXHAUSTA2VALVESA2NEARA2THEA2TOPA2OFA2THEA2COMPRESSI
ONA2STROKEA2TOA2RELEASEA2THEA2COMPRESSEDA2AIR.A2(CORRECTA2AWNSER)
INA2THEA2SYSTEMA2SHOWNA2BELOW,A2THEA2PARTA2ATA2CA2IS:A2-A2Ans--
A.A2ANA2INVERSIONA2VALVE.A2(POSSIBLEA2CORRECTA2AWNSER)
B.A2AA2SAFETYA2VALVE.
C.A2AA2MODULATORA2VALVE.A2(NOTA2CORRECTA2AWNSER)
D.A2AA2RELAYA2VALVE.
AA2MECHANICA2HASA2REMOVEDA2AA2BRAKEA2DRUMA2ANDA2FOUNDA2THEA2BRAKEA
2LININGSA2SOAKEDA2WITHA2GREASE.A2THEA2BRAKEA2LININGSA2SHOULDA2BE:A2-
A2Ans--A.A2REPLACED.A2(CORRECTA2AWNSER)
B.A2SANDEDA2TOA2ROUGHENA2UPA2THEA2FRICTIONA2SURFACE.
C.A2DIPPEDA2INA2LACQUERA2THINNER.
D.A2WASHEDA2WITHA2DENATUREDA2ALCOHOL.
INA2THEA2DRAWINGA2BELOW,A2THEA2PARKINGA2BRAKESA2AREA2APPLIEDA2BY:A2-
A2Ans--A.A2AIRA2PRESSUREA2ATA2POINTA2F.
B.A2VACUUMA2INA2AREAA2B.
C.A2SPRINGA2ATA2POINTA2C.
D.A2PRESSUREA2INA2AREAA2A.A2(NOTA2CORRECTA2AWNSER)
WHATA2ISA2THEA2PURPOSEA2OFA2AA2VACUUMA2BOOSTER?A2-A2Ans--
A.A2TOA2DECREASEA2BRAKEA2PEDALA2EFFORT.A2(POSSIBLEA2CORRECTA2AWNSE
R)
B.A2TOA2PREVENTA2FADEA2UNDERA2HEAVYA2BRAKING.
C.A2TOA2PROVIDEA2ASSISTANCEA2WHENA2THEA2ENGINEA2VACUUMA2ISA2LOW.A2(NO
TA2CORRECTA2AWNSER)
D.A2TOA2MAINTAINA2UNIFORMA2PEDALA2TRAVELA2ASA2THEA2LININGSA2WEAR.
THEA2TRAILERA2BRAKESA2DOA2NOTA2WORK.A2THEA2TRACTORA2SYSTEMA2ISA2ATA2
NORMALA2PRESSURE.A2THEREA2AREA2NOA2LEAKSA2ANDA2THEA2SERVICEA2ANDA2E
MERGENCYA2LINESA2AREA2HOOKEDA2UPA2RIGHT.A2WHATA2COULDA2CAUSEA2THISA
2PROBLEM?A2-A2Ans--A.A2ICEA2INA2THEA2LINESA2ATA2THEA2TRAILER.
, B.A2AA2BADA2RELAYA2VALVE.
C.A2AA2BADA2SAFETYA2RELIEFA2VALVE.
D.A2BOTHA2AA2ANDA2B.A2(CORRECTA2AWNSER)
THEA2RESIDUALA2VALVEA2INA2THEA2MASTERA2CYLINDER:A2-A2Ans--
A.A2LIMITSA2PRESSUREA2BUILDA2UPA2INA2THEA2SYSTEM.
B.A2STOPSA2THEA2FLOWA2TOA2DAMAGEDA2BRAKEA2LINES.
C.A2KEEPSA2SOMEA2PRESSUREA2INA2THEA2SYTEMA2WHENA2THEA2BRAKESA2AREA2R
ELEASED.A2(CORRECTA2AWNSER)
D.A2ISA2OPERATEDA2BYA2ENGINEA2VACUUM.
HIGHERA2THANA2NORMALA2AIRA2PRESSUREA2WOULDA2LIKELYA2BEA2CAUSEDA2BY:
A2-A2Ans--
A.A2AA2GOVENORA2THATA2ISA2BADA2ORA2OUTA2OFA2ADJUSTMENT.A2(POSSIBLEA2CO
RRECTA2AWNSER)
B.A2AA2PLUGGEDA2SAFETYA2VALVE.A2(NOTA2CORRECTA2AWNSER)
C.A2AA2ONE-WAYA2CHECKA2VALVEA2STUCKA2OPEN.
D.A2AA2STICKYA2QUICKA2RELEASEA2VALVE.
IFA2GLADHANDA22A2ISA2UNHOOKEDA2ORA2HASA2AA2SEVEREA2LEAK,A2WHATA2WILLA2
HAPPENA2DURINGA2OPERATION?A2-A2Ans--
A.A2VALVEA2ATA2AA2WILLA2PROTECTA2THEA2PRESSUREA2INA2THEA2DRYA2TANK.
B.A2TRACTORA2BRAKESA2WILLA2APPLYA2AUTOMATICALLY.A2(NOTA2CORRECTA2AW
NSER)
C.A2VALVEA2ATA2CA2WILLA2APPLYA2TRAILERA2BRAKES.
D.A2VALVEA2ATA2BA2WILLA2APPLYA2TRAILERA2BRAKES.
DURINGA2AA2HARDA2STOP,A2ONEA2BRAKEA2HASA2LOCKEDA2ONA2AA2TRAILERA2WITH
A2"S"A2CAMA2BRAKES.A2THEA2SERVICEA2ANDA2EMERGENCYA2LINESA2AREA2HOOKE
DA2UPA2PROPERLYA2ANDA2THEA2SYSTEMA2ISA2ATA2NORMALA2PRESSUREA2BUTA2TH
EA2BRAKESA2WILLA2NOTA2RELEASE.A2WHATA2ISA2THEA2LIKELYA2CAUSEA2OFA2THISA
2PROBLEM?A2-A2Ans--
A.A2THEA2SERVICEA2BRAKEA2CHAMBERA2DIAPHRAGMA2HASA2SPLIT.A2(POSSIBLEA2
CORRECTA2AWNSER)
B.A2THEA2CAMA2HASA2ROLLEDA2OVERA2DUEA2TOA2TOOA2MUCHA2LININGA2WEAR.
C.A2THEA2ANTI-
LOCKA2MODULEA2HASA2BURNEDA2OUTA2ATA2THEA2SENDINGA2UNIT.A2(NOTA2CORR
ECTA2AWNSER)
D.A2THEA2CHAMBERA2SPRINGA2HASA2RUSTEDA2ANDA2ISA2BROKEN.
TOOA2MUCHA2EFFORTA2ISA2REQUIREDA2ONA2THEA2BRAKEA2PEDALA2TOA2STOPA2AA2
TRUCKA2WITHA2AA2VACUUMA2BOOSTER.A2WHATA2ISA2THEA2LIKELYA2CAUSEA2OFA2T
HISA2PROBLEM?A2-A2Ans--A.A2SEIZEDA2AUTOMATICA2ADJUSTERS.
B.A2GLAZEDA2LININGS
C.A2AA2DEFECTIVEA2MODULATORA2VALVE.A2(NOTA2CORRECTA2AWNSER)
D.A2VERYA2HIGHA2ENGINEA2VACUUM.A2(POSSIBLEA2CORRECTA2AWNSER)
MECHANIC STUDY GUIDE QUESTIONS
AND CORRECT ANSWERS
ANA2ENGINEA2BRAKEA2(JACOBSA2BRAKE)A2-A2Ans--A.A2ISA2AA2SELF-
ENERGIZINGA2SERVOA2TYPE.
B.A2ISA2NORMALLYA2USEDA2INA2PLACEA2OFA2AA2SPRINGA2BRAKE.
C.A2RESTRICTSA2THEA2INTAKEA2PORTA2ANDA2CAUSESA2AA2BUILDA2UPA2OFA230-
45A2LBSA2OFA2PRESSURE.
D.A2OPENSA2THEA2EXHAUSTA2VALVESA2NEARA2THEA2TOPA2OFA2THEA2COMPRESSI
ONA2STROKEA2TOA2RELEASEA2THEA2COMPRESSEDA2AIR.A2(CORRECTA2AWNSER)
INA2THEA2SYSTEMA2SHOWNA2BELOW,A2THEA2PARTA2ATA2CA2IS:A2-A2Ans--
A.A2ANA2INVERSIONA2VALVE.A2(POSSIBLEA2CORRECTA2AWNSER)
B.A2AA2SAFETYA2VALVE.
C.A2AA2MODULATORA2VALVE.A2(NOTA2CORRECTA2AWNSER)
D.A2AA2RELAYA2VALVE.
AA2MECHANICA2HASA2REMOVEDA2AA2BRAKEA2DRUMA2ANDA2FOUNDA2THEA2BRAKEA
2LININGSA2SOAKEDA2WITHA2GREASE.A2THEA2BRAKEA2LININGSA2SHOULDA2BE:A2-
A2Ans--A.A2REPLACED.A2(CORRECTA2AWNSER)
B.A2SANDEDA2TOA2ROUGHENA2UPA2THEA2FRICTIONA2SURFACE.
C.A2DIPPEDA2INA2LACQUERA2THINNER.
D.A2WASHEDA2WITHA2DENATUREDA2ALCOHOL.
INA2THEA2DRAWINGA2BELOW,A2THEA2PARKINGA2BRAKESA2AREA2APPLIEDA2BY:A2-
A2Ans--A.A2AIRA2PRESSUREA2ATA2POINTA2F.
B.A2VACUUMA2INA2AREAA2B.
C.A2SPRINGA2ATA2POINTA2C.
D.A2PRESSUREA2INA2AREAA2A.A2(NOTA2CORRECTA2AWNSER)
WHATA2ISA2THEA2PURPOSEA2OFA2AA2VACUUMA2BOOSTER?A2-A2Ans--
A.A2TOA2DECREASEA2BRAKEA2PEDALA2EFFORT.A2(POSSIBLEA2CORRECTA2AWNSE
R)
B.A2TOA2PREVENTA2FADEA2UNDERA2HEAVYA2BRAKING.
C.A2TOA2PROVIDEA2ASSISTANCEA2WHENA2THEA2ENGINEA2VACUUMA2ISA2LOW.A2(NO
TA2CORRECTA2AWNSER)
D.A2TOA2MAINTAINA2UNIFORMA2PEDALA2TRAVELA2ASA2THEA2LININGSA2WEAR.
THEA2TRAILERA2BRAKESA2DOA2NOTA2WORK.A2THEA2TRACTORA2SYSTEMA2ISA2ATA2
NORMALA2PRESSURE.A2THEREA2AREA2NOA2LEAKSA2ANDA2THEA2SERVICEA2ANDA2E
MERGENCYA2LINESA2AREA2HOOKEDA2UPA2RIGHT.A2WHATA2COULDA2CAUSEA2THISA
2PROBLEM?A2-A2Ans--A.A2ICEA2INA2THEA2LINESA2ATA2THEA2TRAILER.
, B.A2AA2BADA2RELAYA2VALVE.
C.A2AA2BADA2SAFETYA2RELIEFA2VALVE.
D.A2BOTHA2AA2ANDA2B.A2(CORRECTA2AWNSER)
THEA2RESIDUALA2VALVEA2INA2THEA2MASTERA2CYLINDER:A2-A2Ans--
A.A2LIMITSA2PRESSUREA2BUILDA2UPA2INA2THEA2SYSTEM.
B.A2STOPSA2THEA2FLOWA2TOA2DAMAGEDA2BRAKEA2LINES.
C.A2KEEPSA2SOMEA2PRESSUREA2INA2THEA2SYTEMA2WHENA2THEA2BRAKESA2AREA2R
ELEASED.A2(CORRECTA2AWNSER)
D.A2ISA2OPERATEDA2BYA2ENGINEA2VACUUM.
HIGHERA2THANA2NORMALA2AIRA2PRESSUREA2WOULDA2LIKELYA2BEA2CAUSEDA2BY:
A2-A2Ans--
A.A2AA2GOVENORA2THATA2ISA2BADA2ORA2OUTA2OFA2ADJUSTMENT.A2(POSSIBLEA2CO
RRECTA2AWNSER)
B.A2AA2PLUGGEDA2SAFETYA2VALVE.A2(NOTA2CORRECTA2AWNSER)
C.A2AA2ONE-WAYA2CHECKA2VALVEA2STUCKA2OPEN.
D.A2AA2STICKYA2QUICKA2RELEASEA2VALVE.
IFA2GLADHANDA22A2ISA2UNHOOKEDA2ORA2HASA2AA2SEVEREA2LEAK,A2WHATA2WILLA2
HAPPENA2DURINGA2OPERATION?A2-A2Ans--
A.A2VALVEA2ATA2AA2WILLA2PROTECTA2THEA2PRESSUREA2INA2THEA2DRYA2TANK.
B.A2TRACTORA2BRAKESA2WILLA2APPLYA2AUTOMATICALLY.A2(NOTA2CORRECTA2AW
NSER)
C.A2VALVEA2ATA2CA2WILLA2APPLYA2TRAILERA2BRAKES.
D.A2VALVEA2ATA2BA2WILLA2APPLYA2TRAILERA2BRAKES.
DURINGA2AA2HARDA2STOP,A2ONEA2BRAKEA2HASA2LOCKEDA2ONA2AA2TRAILERA2WITH
A2"S"A2CAMA2BRAKES.A2THEA2SERVICEA2ANDA2EMERGENCYA2LINESA2AREA2HOOKE
DA2UPA2PROPERLYA2ANDA2THEA2SYSTEMA2ISA2ATA2NORMALA2PRESSUREA2BUTA2TH
EA2BRAKESA2WILLA2NOTA2RELEASE.A2WHATA2ISA2THEA2LIKELYA2CAUSEA2OFA2THISA
2PROBLEM?A2-A2Ans--
A.A2THEA2SERVICEA2BRAKEA2CHAMBERA2DIAPHRAGMA2HASA2SPLIT.A2(POSSIBLEA2
CORRECTA2AWNSER)
B.A2THEA2CAMA2HASA2ROLLEDA2OVERA2DUEA2TOA2TOOA2MUCHA2LININGA2WEAR.
C.A2THEA2ANTI-
LOCKA2MODULEA2HASA2BURNEDA2OUTA2ATA2THEA2SENDINGA2UNIT.A2(NOTA2CORR
ECTA2AWNSER)
D.A2THEA2CHAMBERA2SPRINGA2HASA2RUSTEDA2ANDA2ISA2BROKEN.
TOOA2MUCHA2EFFORTA2ISA2REQUIREDA2ONA2THEA2BRAKEA2PEDALA2TOA2STOPA2AA2
TRUCKA2WITHA2AA2VACUUMA2BOOSTER.A2WHATA2ISA2THEA2LIKELYA2CAUSEA2OFA2T
HISA2PROBLEM?A2-A2Ans--A.A2SEIZEDA2AUTOMATICA2ADJUSTERS.
B.A2GLAZEDA2LININGS
C.A2AA2DEFECTIVEA2MODULATORA2VALVE.A2(NOTA2CORRECTA2AWNSER)
D.A2VERYA2HIGHA2ENGINEA2VACUUM.A2(POSSIBLEA2CORRECTA2AWNSER)