Mityvac MV5530 User manual

COMPRESSION TEST KIT
MODEL ©MV5530
Form 824255
JAN - 08 Section Page
- MV18 - 1B
www.mityvac.com © Indicates change

Page Number - 2 Form 824255
823440
Pressure Hold Adapter
823441
Field Service
Kit
823437
Hose 14MM Long Reach
823436
Hose 14MM Short Reach
823438
Hose 18 MM Short Reach
823435
Hose 14MM
Short Reach
823434
Gauge, Valve
and Hose
823433
14MM - 18MM
Adapter
823431
10MM Adapter
823432
12 MM Adapter
823442
Plastic Case
Part No. Description Part No. Description
823431 10MM Adapter 823437 14 MM Long-Thread x 12 in. (305 MM) Long Hose
823432 12MM Adapter 823438 18 MM Short-Thread x 12 in. (305 MM) Long Hose
823433 14MM Female - 18MM Male Adapter 823440 Pressure Hold Adapter
823434 Gauge Assembly 823441 Field Service Kit
823435 14 MM Short-Thread x 6 in. (150 MM) Long Hose 823442 Case
823436 14 MM Short-Thread x 12 in. (305 MM) Long Hose

Page Number - 3Form 824255
Always read instructions carefully prior to use.
Included in this Kit
• Heavyduty2¾”(70mm)gaugewithhighimpactlens,
rubberboot,andthree(3)scalesofmeasure(psi,
kg/cm2,bar),attachedto10”(250mm)hoseandquick
release coupler
• Four(4)extensionhoses:
• 6½”(165mm)longx14mmthread,short
• 12”(305mm)longx14mmthread,short
• 12”(305mm)longx14mmthread,long
• 12”(305mm)longx18mmthread,short
• One(1)adapter:14mmthread,shortx18mmthread,
long
• Two(2)smallengineadapters
• 10mmthread
• 12mmthread
• One(1)quickreleaseairholdadapter
• Customblow-moldedcase
• Fieldservicekit
Applications
The Mityvac Professional Compression Test Kit can per-
form dry or wet compression tests to determine the amount
of pressure produced in the cylinder of an engine. It can
also be used as a tool for pressurizing an engine cylinder
to hold the valves closed while performing repairs.
How to Perform a Comression Test
Precautions & Diagnostic Notes:
WARNING: DO NOT use the ignition switch during the
compression test on fuel-injected vehicles. Use of a
remote starter switch to crank the engine is recom-
mended. Fuel injectors on many late model vehicles
are triggered by the ignition switch during the cranking
mode, this could result in a re hazard or contamina-
tion of the engine’s oil with fuel.
Always use eye protection when performing compres-
sion tests.
An engine in good operating condition will produce a
certainamountofpressureineachcylinder.Normally,
the cylinders should be within 10 percentage points of
oneanotherandwithinthemanufacturer’sspecications.
The pressure should rise smoothly on each stroke of the
engine,untilitreachesapeak.
Ifthepressurereadingfailstorise,oritremainsthesame
forseveralstrokesoftheengineandbeginstorise,the
likely cause of the problem is a sticking valve.
If two adjacent cylinders show pressure readings of 20 or
morepoundsbelowtheothercylinderreadings,suspecta
blown head gasket.
If a cylinder shows a pressure reading of 15 or more
poundshigherthantheothercylinders,theprobablecause
is carbon build-up inside the cylinder.
The Mityvac Professional Compression Test Kit can
performtwotests:thedrycompressiontestandthewet
compression test. The result of performing these tests will
provideanindicationoftheconditionofthepistonrings,the
cylinders,andvalve-train.
Dry Compression Test Procedures:
1. Refer to the appropriate service manual for the com-
pressionspecicationsspecictotheengineyouare
testing.
2. Start engine and allow engine to run until it reaches nor-
mal operating temperature (usually about 15 minutes.)
TurnengineOFF.
3. Install an auxiliary starter switch in the starting circuit.
4. Whilewearingeyeprotection,usecompressedairto
carefully remove dirt and debris from the area around
the spark plugs.
5. Removesparkplugsoneatatime,markingthenumber
ofthecylindertheywereremovedfrom,andplacethem
onacleanatsurface.Thiswillaidyouinidentifying
problem cylinders by allowing the comparison of spark
plug appearance to the compression level of a given
cylinder.
NOTE: When testing engines with two spark plugs
per cylinder, it is only necessary to remove the
spark plugs located on the exhaust side.
6. Onvehicleswithstandarddistributors,disconnectthe
coil wire (high tension lead) from the distributor cap and
secureittoasuitableground,ordisabletheignitionby
disconnecting the positive (BAT) terminal from the igni-
tion coil.
7. Onvehicleswithadistributorlessignition(DIS),disable
the ignition system by removing the electronic ignition
(control)modulefuse,ordisconnectthecrankangle
sensor.
NOTE: Refer to the appropriate service manual to
determine which fuse or component to temporarily
remove or disconnect.
8. Remove air cleaner from carburetor or throttle body and
securethrottlelinkageinwide-openthrottle(WOT)posi-
tion.
NOTE: NEVER place anything inside the throttle
body; internal damage to the engine could result.
On vehicles equipped with port fuel injection,
remove throttle linkage covers (as necessary) and
secure throttle linkage in the wide-open throttle
(WOT) position.
9. Crank engine several times to ensure removal of any for-

Page Number - 4 Form 824255
eign matter that may have fallen into the cylinders during
preparation for test.
10.Selecttheappropriateadaptertting(14mm,18mmshort
reachor14mm,18mmlong-reach),andthreadadapter
into spark plug hole of cylinder head.
11. Connect the appropriate test hose or adapter to the
gauge assembly.
12.Cranktheengineatleastvecompressionstrokesor
until the pressure reading stops increasing on gauge.
13.Read the pressure level on the gauge and record the
reading along with the cylinder number being tested.
Example: #1-150 psi, #2-145 psi, etc.
14.Repeat this test on each cylinder. If any of the cylinder
readingsarefoundtobeloworuneven,performwet
compression test.
15.Whencompressiontestiscomplete,returnthespark
plugs to their respective cylinders and the throttle and
ignition components to their normal positions.
Wet Compression Test Procedure
CAUTION: DO NOT perform the wet compression test
on any diesel engine. The higher compression in a
diesel engine may cause engine damage or injury to
the technician.
Thewetcompressionisawaytoremovetheinuenceof
thepistonrings,pistonsandcylindersfromthecompres-
siontest.Aftercompletingthedrycompressiontest,squirt
approximately one teaspoon of engine oil into the spark
plug holes and crank the engine several times to seal the
piston rings. Repeat the dry compression test outlined
above. NOTE: If the readings during the wet compression
testaregreater,thenairisleakingaroundwornordam-
aged piston rings. If the reading is approximately the same
forbothwetanddryteststhenthevalves,valveliftersor
the camshaft lobes are worn. Any low reading of cylinder
compression indicates worn or damaged parts.
Small Engine Compression Testing
The Mityvac Professional Compression Test Kit has two
(2)adapters,10mmand12mm,thatallowittobeusedon
smallenginesfoundinlawnmowers,chainsawsandline
trimmers.Tousetheseadapters:
1. Disconnectthesparkplugwireandremovethespark
plug.
2. Thread the appropriate size adapter onto the compres-
sion tester main hose end until the o-ring seats (do not
use a wrench to tighten).
3. Thread the assembly into the cylinder spark plug hole
untiltheo-ringontheadapterseatsrmly(donotusea
wrench to tighten).
4. Ensure the spark plug is grounded to the cylinder head
or is insulated in a way that will prevent an electric
shock hazard.
5. Crank the engine over using the pull cord (or starter if
electric) a minimum of 5 revolutions. This will allow the
cylindertobuildsufcientcompressiontobemeasured.
6. Refer to the manufacturer’s data to determine the cor-
rect reading
Using the Pressure Hold Adapter
The Mityvac Professional Compression Tester comes with
a pressure hold adapter. This adapter is used to perform
valve seal replacement on an engine without removing the
cylinderhead(s).Tousetheadapter:
1. Remove the spark plug from the desired cylinder.
2. Selecttheappropriateextensionhosethatwilltthe
spark plug hole.
3. Usingthevalvecoretool(fromtheeldservicekitin-
cluded),removethevalvecorefromtheendofthehose
and lay it aside.
4. Thread the extension hose into the spark plug hole
until the o-ring seats; do not use pliers or a wrench to
tighten.
5. Attach the Air Hold Adapter to the extension hose.
6. AttachashopairhosetotheAirHoldAdapter,thiswill
maintain air pressure in the cylinder to hold the valves
closed while performing repairs. (It may be necessary
to rotate the engine until all valve are closed and air is
holding in the cylinder)
Note: Air Hold quick connector does not come with a
compressed air line tting to adapt to your air source.
This will have to be purchased separately to t your
system.
Contacting Lincoln Industrial Corp.
LincolnIndustrialCorporation,
OneLincolnWay,
St.Louis,MO63120
Phone:(314)679-4200Ext.4410
Fax:(800)424-5359
E-mail:[email protected]
Fortechnicalquestions,pleasecontactourTechnicalSer-
viceDepartment:
Phone:(314)679-4200Ext4782
Fax:(314)679-HELP(4357)
E-mail:[email protected]
VisitourWebSiteat:www.mityvac.com
TO AVOID PERSONAL INJURY AND/OR VEHICLE DAM-
AGE:
Whilesomeprecautionsarespeciedinthismanual,
and should be noted to avoid personal injury or vehicle

Page Number - 5Form 824255
damage,itisnotpossibleforthesecautionstocoverall
conceivable ways in which service or testing might be
done,orallpossiblehazardousconsequencesofeach
way,norcouldLincolnpossiblyknoworinvestigateall
such ways. It is therefore the responsibility of anyone
usingthismanualoranyotherMityvacproduct,tosatisfy
him or herself completely that neither personal safety nor
vehicle safety will be jeopardized by the service methods
selected. Any such injury or damage is entirely the user’s
responsibility. This device is not to be used in any man-
ner on the human body.
Lincoln Industrial Standard Warranty
LIMITED WARRANTY
LincolnwarrantstheequipmentmanufacturedandsuppliedbyLincolntobefreefromdefectsinmaterialandworkman-
shipforaperiodofone(1)yearfollowingthedateofpurchase,excludingtherefromanyspecial,extended,orlimited
warrantypublishedbyLincoln.Ifequipmentisdeterminedtobedefectiveduringthiswarrantyperiod,itwillberepairedor
replaced,withinLincoln’ssolediscretion,withoutcharge.
ThiswarrantyisconditioneduponthedeterminationofaLincolnauthorizedrepresentativethattheequipmentisdefec-
tive.Toobtainrepairorreplacement,youmustshiptheequipment,transportationchargesprepaid,withproofofpur-
chase to a Lincoln Authorized Warranty and Service Center within the warranty period.
Thiswarrantyisextendedtotheoriginalretailpurchaseronly.Thiswarrantydoesnotapplytoequipmentdamaged
fromaccident,overload,abuse,misuse,negligence,faultyinstallationorabrasiveorcorrosivematerial,equipmentthat
hasbeenaltered,orequipmentrepairedbyanyonenotauthorizedbyLincoln.Thiswarrantyappliesonlytoequipment
installed,operatedandmaintainedinstrictaccordancewiththewrittenspecicationsandrecommendationsprovidedby
Lincolnoritsauthorizedeldpersonnel.
THISWARRANTYISEXCLUSIVEANDISINLIEUOFANYOTHERWARRANTIES,EXPRESSORIMPLIED,INCLUD-
ING,BUTNOTLIMITEDTO,THEWARRANTYOFMERCHANTIBILITYORWARRANTYOFFITNESSFORAPAR-
TICULARPURPOSE.
InnoeventshallLincolnbeliableforincidentalorconsequentialdamages.Lincoln’sliabilityforanyclaimforlossordam-
agesarisingoutofthesale,resaleoruseofanyLincolnequipmentshallinnoeventexceedthepurchaseprice.Some
jurisdictionsdonotallowtheexclusionorlimitationofincidentalorconsequentialdamages,thereforetheabovelimitation
or exclusion may not apply to you.
Thiswarrantygivesyouspeciclegalrights.Youmayalsohaveotherrightsthatvarybyjurisdiction.
CustomersnotlocatedintheWesternHemisphereorEastAsia:PleasecontactLincolnGmbH&Co.KG,Walldorf,Ger-
many,foryourwarrantyrights.
Lincoln Industrial Contact Information
To nd Lincoln Industrial’s Nearest Service Center
Calloneofthefollowingnumbers,youmayalsouseourWebsite
Customer Service 314-679-4200
Website:lincolnindustrial.com