T4 ASE BRAKES EXAM QUESTIONS WITH CORRECT RATIONALES
Psi closs crate cfor cStraight cTruck c- cCORRECT cANS✔✔2 cpsi/minute
Psi closs crate cfor ccombination cvehicle c- cCORRECT cANS✔✔less cthan c3 cpsi/minute
Service cBrake cPressure cDrop cTest c- cCORRECT cANS✔✔Apply cservice cbrake cto c90 cpsi. cLoss crate cshould cbe cless cthan c3
cpsi/minute cfor cstraight cvehicles cand cless cthan c4 cpsi/minute cfor ccombination cvehicles.
Improperly cadjusted cbrake cshoes c- cCORRECT cANS✔✔Cause
1) cbrake cimbalance
2) cincreased cstopping cdistance
3) cexcessive cheat cand cwear
Instability cand cpremature cwear c- cCORRECT cANS✔✔a c4 cpsi cdifference cin cthe cair cdelivery cbetween caxles cis cenough cto
ccause cinstability cand cpremature cwear.
Troubleshooting cpoor cbrake cperformance cdue cto cair c- cCORRECT cANS✔✔1) cinspect cair ccompressor
2) cverify cpressure cbuild cup
3) clook cfor cclogged cair ccompressor cfilter
4) cpossible cslipping cbelt
5) cpossible cair cleaks
6) cpossible cdefective cgovernor
Pressure cGovernors c- cCORRECT cANS✔✔1) cregulates cair cgoing cto csystem
2) cadjustable cpressure
3) cdefective cgovernor cor cout cof cadjustment ccan ccause ccompressor cto cfunction cimproperly. c
4) cdesigned cto cregulate cthe ccompressors coutput.
5) cmay cbe cattached cto ccompressor cor cexternally cmounted.
Air cCompressors c- cCORRECT cANS✔✔1) cPower cis ctransferred cto cthe cair ccompressor cby ceither can cinternal cgear cor cby can
cexternal cbelt. cBelt cis cmost ccommon.
2)air ccan cbe cdrawn cdirectly cfrom cthe catmosphere cthrough ca cfilter.
3) cPistons cpush cthe cair cthrough ca cdischarge cvalve cto cthe csupply creservoir.
Supply cReservoir c"Wet cTank" c- cCORRECT cANS✔✔1) ctank cclosest cto cthe ccompressor. c
2) c"pop coff cvalve" clocated con cthis ctank cto ckeep cfrom cover cpressuring cthe csystem.
Pop-off cvalve c- cCORRECT cANS✔✔Also cknown cas cthe cpressure crelief cvalve, cexhaust cvalve, cadjustable cpressure climiting
c(APL) cvalve, cor coverflow cvalve; cthis cvalve cis cthe cpoint cof cexit cof cexcessive cpressure cbuildup cbefore cdamaging cair
ccomponents.
Manual cand cAutomatic cDrain cValves c- cCORRECT cANS✔✔1) cinstalled cin ceach creservoir/tank cto chelp cpurge cthe csystem cfrom
cmoisture.
2)Used cin chigh chumid cor cwet cclimates.
3) cmanual cdrain cvalves cshould cbe cdrained con ca cdaily cbasis
Air cDryer c- cCORRECT cANS✔✔1) cused cto ckeep ccondensation cout cof cthe csystem cusing ca cdesiccant cmaterial cto cremove
cmoisture.
2
, Air cCompressor ctroubleshooting c- cCORRECT cANS✔✔1) ccan cdevelop cair cleaks cand cpass coil cinto cthe cbrake csystem cwhich
cwill ccause cpoor cbraking cand cor cgrabbing cor cdragging. c
2) cclogged cair cintake cfilter cwill ccause cslow cpressure cbuild cup.
Compressor coil cchecks c- cCORRECT cANS✔✔1) cengine coil cshould cbe cchecked cfor ccompressors cthat cget clubrication cfrom
cengine. c
2) cOil csump ccompressors chave ctheir cown coil creservoirs cand cshould cbe cchecked cdaily.
Compressor cPressure cTesting c- cCORRECT cANS✔✔1) cwith cengine crunning cat cidle; cair cpressure cshould cbuild cfrom c85-100
cpsi cwithin c45 cseconds.
2) cif cthe cengine cis crunning cat cfull cgoverned crpm; cpressure cshould cbuild cwithin c25 cseconds cand cthe ccompressor cshould
cmaintain ca cconstant cpressure cof c100-120 cpsi.
Troubleshooting cair cleaks c- cCORRECT cANS✔✔1) cif cno cleaks care cfound ccheck cto csee cif cdirty cair cfilter cis crestricting cthe
cintake cof cthe ccompressor.
Gear cDriven cCompressor c- cCORRECT cANS✔✔1) cmust cbe cmeshed cwith cthe ctiming cgear con cthe cengine cbefore cinstallation.
cA cmisaligned cgear ccan ccause cpoor cpressure cbuildup.
2) cCompressor ctiming ccan cbe cachieved cby caligning cthe ctiming cmarks con cthe cgear cand ccrankcase.
Governor cDiagnosing c- cCORRECT cANS✔✔To ccheck cwith cengine crunning: clet csystem cfill cto cabout c125psi. cSlowly creduce cair
cin csystem cby capply cand creleasing cthe cair cbrakes. cObserve cthe cpressure. cAt cabout c100 cpsi cthe cpressure cshould crise
cindicating cthe cgovernor cis ccutting cin cand cout cat cproper cpsi.
Check cfor cleaks cby capplying csoapy cwater cat cexhaust cvent cvalve. cLeakage cin cexcess cof c3 cinch csoap cbubble cindicates
creplacement cof cgovernor.
Adjusting cgovernor c- cCORRECT cANS✔✔1) cbefore cadjusting cgovernor, ccheck cthe caccuracy cof cthe cgauge cwith ca ctest cgauge.
2)each c1/4 cturn cof cthe cadjustment cscrew ccan craise cor clower cpsi cby capprox c4 cpsi.
3) cdo cnot cadjust cgovernor cif cscrew cis csheared coff.
Air chose cand clines c- cCORRECT cANS✔✔1) cair clines care cmade cup cof ceither ccopper cor cstiff cnylon cwhere cno cmovement cis
cpresent.
2)Air choses care cmade cof crubber cand care cdesigned cto cmove cwit ctrucks csuspension, csteering cetc. cHoses care ccomprised cof
clayers cof csynthetic crubber, callowing chose cto cbe cstrong cbut cmaintains cits cflexability.
Replacement cof clines cand choses. c- cCORRECT cANS✔✔1) cshould cbe creplaced cif cbulging cor cswelling cis cpresent cwhen cthe
cbrakes care cfully capplied.
2)Improper crouting, cclamping cor ccrimping cis ccause cfor creplacement. c
3)it cis cnot crecommended cand cillegal cto csplice cor cpatch ca cleaking cbrake cline cor chose.
4)must cbe creplaced cwith cDOT capproved cmaterial cintended cfor cspecific capplication. c
5) cdo cnot cchange cthe cdiameter cof cthe chose.
Diagnosing cAir cDryer c- cCORRECT cANS✔✔1) ca cdefective cdryer cwill callow cmoisture cand cother ccontaminents cinto cthe cbrake
csystem.
2) coperates cin ctwo ccycles. cCharge cand cPurge.
3) cCharge: caccepts cair cwith cmoisture cor cdebris cfrom cair ccompressor. cTravels cthrough can coil cseparator cwhere ccontaminates
care cremoved. cMoisture cis cremoved cby cdesiccant.
4) cPurge: conce cgovernor cdetermines cpressure cis cachieved cit csignals cthe cdryer cto cpurge cany ccontaminants cand cmoisture.
cCycle cis crepeated.
Foot cValves c- cCORRECT cANS✔✔1) ccan ceither cbe cfloor cor cfirewall cmounted.
2) cdesigned cto cprovide cpressure cin cthe c5-80 cpsi crange. c
3) culrtasonic cleak cdetector ccan cbe cused cat cthe cexhaust cport cto cdetect cinternal cleaks.
4)Primary cand csecondary cvalve cports cin cpedal cshould cbe cwithin c5 cpsi cof ceach cother. cReplace cfoot cpedal cif cmore cthan c5
cpsi cdifference. c
5) ctroubleshoot cleaks con cvalves. c1 cin csoap cbubble cevery c5 cseconds cpermissible.
Psi closs crate cfor cStraight cTruck c- cCORRECT cANS✔✔2 cpsi/minute
Psi closs crate cfor ccombination cvehicle c- cCORRECT cANS✔✔less cthan c3 cpsi/minute
Service cBrake cPressure cDrop cTest c- cCORRECT cANS✔✔Apply cservice cbrake cto c90 cpsi. cLoss crate cshould cbe cless cthan c3
cpsi/minute cfor cstraight cvehicles cand cless cthan c4 cpsi/minute cfor ccombination cvehicles.
Improperly cadjusted cbrake cshoes c- cCORRECT cANS✔✔Cause
1) cbrake cimbalance
2) cincreased cstopping cdistance
3) cexcessive cheat cand cwear
Instability cand cpremature cwear c- cCORRECT cANS✔✔a c4 cpsi cdifference cin cthe cair cdelivery cbetween caxles cis cenough cto
ccause cinstability cand cpremature cwear.
Troubleshooting cpoor cbrake cperformance cdue cto cair c- cCORRECT cANS✔✔1) cinspect cair ccompressor
2) cverify cpressure cbuild cup
3) clook cfor cclogged cair ccompressor cfilter
4) cpossible cslipping cbelt
5) cpossible cair cleaks
6) cpossible cdefective cgovernor
Pressure cGovernors c- cCORRECT cANS✔✔1) cregulates cair cgoing cto csystem
2) cadjustable cpressure
3) cdefective cgovernor cor cout cof cadjustment ccan ccause ccompressor cto cfunction cimproperly. c
4) cdesigned cto cregulate cthe ccompressors coutput.
5) cmay cbe cattached cto ccompressor cor cexternally cmounted.
Air cCompressors c- cCORRECT cANS✔✔1) cPower cis ctransferred cto cthe cair ccompressor cby ceither can cinternal cgear cor cby can
cexternal cbelt. cBelt cis cmost ccommon.
2)air ccan cbe cdrawn cdirectly cfrom cthe catmosphere cthrough ca cfilter.
3) cPistons cpush cthe cair cthrough ca cdischarge cvalve cto cthe csupply creservoir.
Supply cReservoir c"Wet cTank" c- cCORRECT cANS✔✔1) ctank cclosest cto cthe ccompressor. c
2) c"pop coff cvalve" clocated con cthis ctank cto ckeep cfrom cover cpressuring cthe csystem.
Pop-off cvalve c- cCORRECT cANS✔✔Also cknown cas cthe cpressure crelief cvalve, cexhaust cvalve, cadjustable cpressure climiting
c(APL) cvalve, cor coverflow cvalve; cthis cvalve cis cthe cpoint cof cexit cof cexcessive cpressure cbuildup cbefore cdamaging cair
ccomponents.
Manual cand cAutomatic cDrain cValves c- cCORRECT cANS✔✔1) cinstalled cin ceach creservoir/tank cto chelp cpurge cthe csystem cfrom
cmoisture.
2)Used cin chigh chumid cor cwet cclimates.
3) cmanual cdrain cvalves cshould cbe cdrained con ca cdaily cbasis
Air cDryer c- cCORRECT cANS✔✔1) cused cto ckeep ccondensation cout cof cthe csystem cusing ca cdesiccant cmaterial cto cremove
cmoisture.
2
, Air cCompressor ctroubleshooting c- cCORRECT cANS✔✔1) ccan cdevelop cair cleaks cand cpass coil cinto cthe cbrake csystem cwhich
cwill ccause cpoor cbraking cand cor cgrabbing cor cdragging. c
2) cclogged cair cintake cfilter cwill ccause cslow cpressure cbuild cup.
Compressor coil cchecks c- cCORRECT cANS✔✔1) cengine coil cshould cbe cchecked cfor ccompressors cthat cget clubrication cfrom
cengine. c
2) cOil csump ccompressors chave ctheir cown coil creservoirs cand cshould cbe cchecked cdaily.
Compressor cPressure cTesting c- cCORRECT cANS✔✔1) cwith cengine crunning cat cidle; cair cpressure cshould cbuild cfrom c85-100
cpsi cwithin c45 cseconds.
2) cif cthe cengine cis crunning cat cfull cgoverned crpm; cpressure cshould cbuild cwithin c25 cseconds cand cthe ccompressor cshould
cmaintain ca cconstant cpressure cof c100-120 cpsi.
Troubleshooting cair cleaks c- cCORRECT cANS✔✔1) cif cno cleaks care cfound ccheck cto csee cif cdirty cair cfilter cis crestricting cthe
cintake cof cthe ccompressor.
Gear cDriven cCompressor c- cCORRECT cANS✔✔1) cmust cbe cmeshed cwith cthe ctiming cgear con cthe cengine cbefore cinstallation.
cA cmisaligned cgear ccan ccause cpoor cpressure cbuildup.
2) cCompressor ctiming ccan cbe cachieved cby caligning cthe ctiming cmarks con cthe cgear cand ccrankcase.
Governor cDiagnosing c- cCORRECT cANS✔✔To ccheck cwith cengine crunning: clet csystem cfill cto cabout c125psi. cSlowly creduce cair
cin csystem cby capply cand creleasing cthe cair cbrakes. cObserve cthe cpressure. cAt cabout c100 cpsi cthe cpressure cshould crise
cindicating cthe cgovernor cis ccutting cin cand cout cat cproper cpsi.
Check cfor cleaks cby capplying csoapy cwater cat cexhaust cvent cvalve. cLeakage cin cexcess cof c3 cinch csoap cbubble cindicates
creplacement cof cgovernor.
Adjusting cgovernor c- cCORRECT cANS✔✔1) cbefore cadjusting cgovernor, ccheck cthe caccuracy cof cthe cgauge cwith ca ctest cgauge.
2)each c1/4 cturn cof cthe cadjustment cscrew ccan craise cor clower cpsi cby capprox c4 cpsi.
3) cdo cnot cadjust cgovernor cif cscrew cis csheared coff.
Air chose cand clines c- cCORRECT cANS✔✔1) cair clines care cmade cup cof ceither ccopper cor cstiff cnylon cwhere cno cmovement cis
cpresent.
2)Air choses care cmade cof crubber cand care cdesigned cto cmove cwit ctrucks csuspension, csteering cetc. cHoses care ccomprised cof
clayers cof csynthetic crubber, callowing chose cto cbe cstrong cbut cmaintains cits cflexability.
Replacement cof clines cand choses. c- cCORRECT cANS✔✔1) cshould cbe creplaced cif cbulging cor cswelling cis cpresent cwhen cthe
cbrakes care cfully capplied.
2)Improper crouting, cclamping cor ccrimping cis ccause cfor creplacement. c
3)it cis cnot crecommended cand cillegal cto csplice cor cpatch ca cleaking cbrake cline cor chose.
4)must cbe creplaced cwith cDOT capproved cmaterial cintended cfor cspecific capplication. c
5) cdo cnot cchange cthe cdiameter cof cthe chose.
Diagnosing cAir cDryer c- cCORRECT cANS✔✔1) ca cdefective cdryer cwill callow cmoisture cand cother ccontaminents cinto cthe cbrake
csystem.
2) coperates cin ctwo ccycles. cCharge cand cPurge.
3) cCharge: caccepts cair cwith cmoisture cor cdebris cfrom cair ccompressor. cTravels cthrough can coil cseparator cwhere ccontaminates
care cremoved. cMoisture cis cremoved cby cdesiccant.
4) cPurge: conce cgovernor cdetermines cpressure cis cachieved cit csignals cthe cdryer cto cpurge cany ccontaminants cand cmoisture.
cCycle cis crepeated.
Foot cValves c- cCORRECT cANS✔✔1) ccan ceither cbe cfloor cor cfirewall cmounted.
2) cdesigned cto cprovide cpressure cin cthe c5-80 cpsi crange. c
3) culrtasonic cleak cdetector ccan cbe cused cat cthe cexhaust cport cto cdetect cinternal cleaks.
4)Primary cand csecondary cvalve cports cin cpedal cshould cbe cwithin c5 cpsi cof ceach cother. cReplace cfoot cpedal cif cmore cthan c5
cpsi cdifference. c
5) ctroubleshoot cleaks con cvalves. c1 cin csoap cbubble cevery c5 cseconds cpermissible.
