BENDIX TU-FLO 400-500-1000 AIR COMPRESSOR Test 1 Excessive Oil Leakage at Head Gasket, Action

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Tests

Test 1: Excessive Oil Leakage at the

Head Gasket

Exterior leaks at the head gasket are not a sign that oil is being passed into the air charging system. Oil weepage at the head gasket does not prevent the compressor from building air.

Observe the amount of weepage from the head gasket.

If the oil is only around the cylinder head area, it is acceptable (return the vehicle to service), but, if the oil weepage extends down to the nameplate area of the compressor, the gasket can be replaced.

LOOK

FOR

WEEPAGE

Test 2: Air Brake System and Accessory Leakage

Inspect for air leaks when working on a vehicle and repair them promptly.

Park the vehicle on level ground and chock wheels. Build system pressure to governor cut-out and allow the pressure to stabilize for one minute.

Step 1: Observe the dash gauges for two additional minutes without the service brakes applied.

Step 2: Apply the service brakes and allow the pressure to stabilize. Continue holding for two minutes (you may use a block of wood to hold the

pedal in position.) Observe the dash gauges.

If you see any noticeable decrease of the dash air gauge readings (i.e. more than 4 psi, plus two psi for each additional trailer) during either two minute test, repair the leaks and repeat this test to confirm that they have been repaired.

Air leaks can also be found in the charging system, parking brakes, and/or other components - inspect and repair as necessary.

Test 3: Air Compressor Discharge

Temperature and Air Dryer Inlet

(* Note that only vehicles that have passed Test 2

 

Temperature*

 

would be candidates for this test.)

Caution: The temperatures used in this test

4.

Then, while maintaining max rpm and

are not normal vehicle conditions.

 

pressure range, measure and record the

Above normal temperatures can cause oil (as

 

 

surface temperature of the fittings:

vapor) to pass through the air dryer into the

 

 

ð at the compressor discharge port. (T1).

air brake system.

 

 

ð at the air dryer inlet fitting. (T2).

This test is run with the engine at normal

 

 

Use a touch probe thermocouple for

operating temperature, with engine at max. rpm.

 

 

measuring the temperature.

If available, a dyno may be used.

 

5.

See table below.

1. Allow the compressor to build the air system

6.

Retest before returning the vehicle to service.

pressure to governor cut-in.

 

 

 

 

 

2. Pump the brakes to bring the dash gauge

 

 

 

 

 

T1

 

T2

 

 

pressure to 90 psi.

 

 

 

3. Allow the compressor to build pressure from

Compressor

Air Dryer

Action

 

Discharge

Inlet

 

95 to 105 psi gauge pressure and maintain

Fitting

Fitting

 

 

this pressure range by cycling the brakes for

 

 

 

 

 

under

under

Temperatures are within

 

five (5) minutes.

 

360°F

200°F

normal range for this test, check

 

 

T1

 

 

 

other symptoms. Go to 4.0 (h).

 

 

 

 

 

 

 

 

under

over

This could indicate a discharge

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

360°F

200°F

line problem (e.g. restriction).

 

 

 

 

 

 

 

 

 

 

 

Call 1-800-AIR-BRAKE

 

 

T2

 

 

 

 

(1-800-247-2725)

 

 

 

 

 

 

 

 

 

 

 

and speak with our Tech Team.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

over

__

Compressor is running hot.

 

 

 

 

 

 

 

 

360°F

 

Check coolant 4(f) and/or

 

 

Discharge Line

 

 

 

 

 

 

discharge line 4(g).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Contents SD-01-326 Description GeneralIntake and Compression Loaded OperationCompressor & the AIR Brake System Polyurethane Sponge Strainer Fig Preventive MaintenanceCooling Installation ENGINE-LUBRICATED Types Removing and InstallingDRY Element Pleated Paper AIR Strainer FIG AIR Leakage TestsRemoving and Disassembly DisassemblyConnecting ROD Assemblies Crankcase Base Plate or AdapterTU-FLO400 AIR Compressor Vertical Mount Engine Lubricated Crankcase FigInspection of Parts CleaningInlet Valves and Seats Crankcase and END CoversCylinder Bores PistonsRepairs Installing Cylinder Block AssemblyInstalling Crankshaft Pistons and Connecting RodsBaseplate Page Tabulated Data InstallationScheduled Maintenance Symptom Number Test ProceduresMaintenance & Usage Guidelines Introduction to the Air Brake Charging System High Air Use Low Air UseOil Test Card Not a valid test Results Symptom What it may indicate What you should doDiscontinue using this test Oil at air dryer purge/exhaust or surrounding area Oil on the Outside of the CompressorMaintenance Oil in Supply or Service Reservoir air dryer installedInsufficient coolant flow Oil in SupplyOil in Supply or Service Reservoir Or compressor dis Oil in ping tankCharge aftercooler Air brake Charging systemAir brake charging system seems slow to build pressure Releases air Compressor builds too much air Time Air dryer Safety valve releases airNoisy Leaks coolant Coolant line fittingsAction Test 2 Air Brake System and Accessory LeakageTest 1 Excessive Oil Leakage at Head Gasket Test 6 Compressor Unloader Leakage Test 4 Governor MalfunctionTest 5 Governor Control Line Page Appendix a Information about the Basic Test Kit Bendix P/N Bendix Air System Inspection Cup Basic Test InformationStep B Measure the Charging System Contents Checklist for TechnicianStep a Select one Is foundStep D Air Brake System Leakage Test Typical P&D, School Bus and Line Haul Technical BulletinSystem Leakage Thawing Frozen Air Lines Page