Sealey Ct951.v4 User manual

PETROL ENGINE COMPRESSION TEST KIT

3PC

MODEL NO: CT951.V4

Thank you for purchasing a Sealey product. Manufactured to a high standard, this product will, if used according to these

instructions, and properly maintained, give you years of trouble free performance.

IMPORTANT: PLEASE READ THESE INSTRUCTIONS CAREFULLY. NOTE THE SAFE OPERATIONAL REQUIREMENTS, WARNINGS & CAUTIONS. USE

THE PRODUCT CORRECTLY AND WITH CARE FOR THE PURPOSE FOR WHICH IT IS INTENDED. FAILURE TO DO SO MAY CAUSE DAMAGEAND/OR

PERSONAL INJURY AND WILL INVALIDATE THE WARRANTY. KEEP THESE INSTRUCTIONS SAFE FOR FUTURE USE.

1. SAFETY

WARNING! Ensure all Health & Safety, local authority and general workshop practice regulations are strictly adhered to when using

tools.

8DO NOT use tester if damaged.

8DO NOT use the tester for a task it is not designed to perform.

9Maintain the tester in good and clean condition for best and safest performance. Use an authorised service agent.

9Wear approved eye protection. A full range of personal safety equipment is available from your Sealey stockist.

9Wear suitable clothing to avoid snagging. Remove ties, watches, rings and other loose jewellery and contain long hair.

9 Maintaincorrectbalanceandfooting.Ensuretheoorisnotslipperyandwearnon-skidshoes.

9Account for all tools and equipment being used and do not leave them in, on or near engine.

9Keep the work area clean, uncluttered and ensure that there is adequate lighting.

8DO NOToperatethetoolwhenyouaretiredorundertheinuenceofalcohol,drugsorintoxicatingmedication.

9When not in use, place in original protective case and store in a safe, dry, childproof location.

9Always refer to the vehicle manufacturer’s service instructions or a proprietary manual, to establish the current procedure and data.

2. INTRODUCTION

Largeeasytoreadgaugewithimperialandmetricreadings.Sidereleasevalveand12”exiblehoseforeasyreach.Pressurerange

0-300psi/0-2000kpa.Screwin14and18mmadaptorsand150mmrigidstemconeadaptortsmostsparkplugholes.Suppliedinstorage

case.

3. OPERATION

3.1. PREPARATION

3.1.1. Run engine until normal operating temperature is achieved.

3.1.2. Stop engine, loosen spark plugs one turn, with an air hose, blow dirt and debris from the spark plug wells.

3.1.3. Remove all spark plugs.

3.1.4. Ifttedwithacarburettorsetthethrottlevalvewideopen.

WARNING! The ignition system MUST be disabled. Failure to disable could result in damage to the ignition system or ECU.

3.1.5. Unplug the low tension connections to the coil. If you aren’t sure how to disable the vehicle ignition system then consult the

manufacturer’s service instructions or a proprietary manual before you start. It is also good practice to unplug the fuel injectors or

 disablethefuelpump,especiallyoncarsttedwithacatalyticconverter.Thispreventsunburnedfuelgettingintotheexhaustsystem

during the test.

3.2. COMPRESSION TEST

3.2.1. Usingtheappropriatethreadedadaptor,screwthetester(g1),intoasparkplughole(nger-tight-donotuseawrench)orusing

 thepushtting(g2),holdthecompressiontesterrmlyagainstthesparkplugaperture.

3.2.2. Cranktheengineuntilnoincreaseinpressureisnotedonthegaugereading;usually3or4revolutionsissu󰀩cient.Takeanoteofthe

pressure reading.

3.2.3. Decompresstesterbypressingreleasevalve(g1)removethecompressiontesterfromthesparkplugholeandproceedtothenext

cylinder. Note pressure reading for each cylinder.

NOTE: Theactualgureinpsiisnotimportant.Itisimportantthatallcylindershaveapproximatelythesamecompressionpressures.

Onhighcompressionengines(150psiandhigher)thepressureshouldnotvarymorethan15psifromthehighesttothelowest 

cylinder reading.

 Onlowcompressionengines(under150psi)thepressureshouldnotvarymorethan10psifromthehighesttothelowestcylinder 

reading.

NOTE: Compression readings are unbalanced when one or two cylinders are considerably higher or lower than the others.

3.3. CAUSES OF UNBALANCE

3.3.1. Low cylinder compression is caused by leakage from:

A.HeadGasket-explosivesoundwhenrunningengine.

B.HeadGasketbetweencylinders-compressionwillbelowintwoadjacentcylindersandwatermayappearincylindersor 

crankcase.

C. Valves that are not seating properly.

D.Pistonringsthatareworn.Pourateaspoonofoilintothesparkplugholetosealtherings.Repeattest.

CT951.V4Issue111/03/22

Original Language Version

Refer to

instructions Wear eye

protection Wear protective

gloves Wear safety

footwear Wear protective

clothing

If compression reading increases, the rings are worn; no increase indicates a bad valve.

3.3.2. High cylinder compression is caused by accumulation of carbon in that cylinder. High compression readings in all cylinders is

 causedbyanevenaccumulationofcarboninallcylinders.Thismaycausedetonationpinkingthatisdi󰀩culttoeliminate.

CT951.V4Issue111/03/22

Original Language Version

Sealey Group, Kempson Way, Suffolk Business Park, Bury St Edmunds, Suffolk. IP32 7AR

01284 757500 01284 703534 sales@sealey.co.uk www.sealey.co.uk

Note: It is our policy to continually improve products and as such we reserve the right to alter data, specifications and component parts without prior

notice. Pleasenotethatotherversionsofthisproductareavailable.Ifyourequiredocumentationforalternativeversions,pleaseemailorcall

ourtechnicalteamontechnical@sealey.co.ukor01284757505.

Important: No Liability is accepted for incorrect use of this product.