INTRODUCTION
SafetyrulesServiceprecautionarystatements
SERVICEPRECAUTIONARYSTATEMENTS
LeakTesting
Recharginganairconditioningsystemthatleakssimplyallowsmorerefrigeranttoescapeintotheatmosphereand
ultimatelyleavesthesystemnon-functioningandinneedofadditionalcharging.
Therefore,theproperserviceprocedureistolocateandxanyleaksbeforeputtinganymorerefrigerantintothe
system.
Ifalargeamountofrefrigeranthasleakedout,thesystempressurewillbetoolowtoidentifyallbutthelargestleaks.
Inthiscase,partiallyrechargethesystemwithnomorethanonepoundofrefrigeranttocheckforleaks.
NOTICE:•Anyrefrigerantintroducedintothesystemforthepurposeofndingleaksmustalsoberecoveredwithout
releasingitintotheatmosphere.
•AlwaysusethesametypeofrefrigerantforcheckingleaksaswasoriginallyinstalledintotheACsystembythe
manufacturer.
•Neverusecompressedairtodetectsystemleaks.Theintroductionofairintothesystemmaycreateareor
explosionhazard,mayoverloadthedesiccantwithmoisture,andcouldcontaminatethesystemwithdirtandimproper
oil.
Allautomotivetypeairconditioningsystemsleaktosomeextent.Whenservicingthemitisimportantthatleakagebe
minimized.Muchofthenormalleakagecomesfromtheslowseepageofrefrigerantthroughtheexiblehoses.Other
commonsourcesofleaksareatjointsbetweentheexiblehoseandmetaltubingoratthreadedhoseconnections.
Theseareusuallymuchlargerleaksthanthenaturalseepagethroughthewallsofthehoseandarealmostalways
repairable.
ResearchbytheEPAhasfoundthatleakdetectioncanbedifcult,butexistinghalogenleakdetectionsystemsare
adequateforthemajortaskofndingandrepairingleakscausingcomplaints.Dyestainsarenotverysatisfactoryfor
ndingsmallleaks.
Newerelectronicleakdetectorsmayofferevenbetterleakdetectioncapabilities.However,nosinglemethodcannd
everyleak.Electronicleakdetectorsmaynotdetectleaksofallrefrigerants.Forexample,olderunitsdesignedto
detectR12maynotdetect
R134A.Besurethattheleakdetectoryouuseisstate-of-the-artandthatitisdesignedto
detecttherefrigerantinthesystemyouareservicing.
Serviceprofessionalsmustbeextremelydiligentintheirworktocorrectallpossibleleaks.Diligenceisessentialto
ensurethatnosmall,difcult-to-ndleaksgoundetected.
Beforeleavingajob,makeonelastleakcheck.Catchingaleakjustafterservicewillsaveaninconvenientand
expensivereturnvisit.
Relling
Relltheairconditioningsystemusingtheweightmethod.ThelubricantsusedinR134atendtolayerontothewalls
oftherefrigerationsystem.Thislayeringobscurestheviewthroughthesightglass.VisualmethodsofrellingR134a
systemswillresultinimpropersystemcharging.Forthisreason,wedonotrecommendtheoldpracticeoftoppingoff
apartiallydischargedairconditioningsystemusingthesightglass.TheFarmalltractorsuse1.0kg(2.2lb)ofR134A
refrigerant.
4785194503/02/2016
9
To Next Page
Loading...
Need help?
General