Bendix-commercial-vehicle-systems TU-FLO 750 COMPRESSOR 6/08 User Manual

1® SD-01-344DESCRIPTIONThe function of the air compressor is to provide and main-tain air under pressure to operate devices in the air brake and/or au

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11in. should be rebored or honed oversize. Oversized pistons and piston rings are available in .010 in., .020 in. and .030 in. oversizes. Cylinder bor

12INLET VALVES AND SEATS Inlet valves and springs should be replaced. However, if the inlet valve seats show signs of slight nicks or scratches, they

132. Install the compression rings (23) in the proper grooves with the “pip” mark toward the top of the piston. (Refer to Figure 14.) Check the ring

14Minimum oil pressure required atengine idling speed ... 15 PSIGMinimum oil pressure required atmaximum gove

157. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system

*This guide is only for vehicles that use desiccant air dryers.The guide consists of an introduction to air brake charging system components, a table

17Introduction to the Air Brake Charging SystemPowered by the vehicle engine, the air compressor builds the air pressure for the air brake system. The

18Compressor with up to 25% duty cycleFootnotes: 1 With increased air demand the air dryer cartridge needs to be replaced more often.2 Use the drai

19Air Brake Charging System TroubleshootingHow to use this guide:1.0 Oil Test Card ResultsNot a valid test.Discontinue using this test. Do not use th

2OPERATIONThe compressor is driven by the vehicle engine and is operating continuously while the engine is running. Actual compression of air is contr

Symptom: What it may indicate: What you should do: 202.2 Oil leaking from compressor:(a) Excessive leak at head gasket. (b) Leak at bottom cover p

214.0 Oil in Supply or Service Reservoir(air dryer installed)(If a maintained Bendix® PuraGuard® system fi lter or Bendix® PuraGuard® QC™ oil coalesci

Symptom: What it may indicate: What you should do: 22(e) Air compressor discharge and/or air dryer inlet temperature too high.(f) Insuffi cient coo

Symptom: What it may indicate: What you should do: 23(i) Poorly fi ltered inlet air (poor air quality to compressor).(j) Governor malfunction or

Symptom: What it may indicate: What you should do: 248.0 Oil in ping tank or compressor dis-charge aftercooler.Air brake charging system is functi

Symptom: What it may indicate: What you should do: 25(g) Restricted air inlet (not enough air to compressor). Check compressor air inlet line for

Symptom: What it may indicate: What you should do: 2610.0 Air charging system doesn’t build air. (a) Governor malfunction*. (b) Restricted discha

Symptom: What it may indicate: What you should do: 2715.0 Compressor constantly cycles (compressor remains unloaded for a very short time.)(a) Air

Symptom: What it may indicate: What you should do: 28This guide attempts to cover most com-pressor system problems. Here are some rare sources of p

29TestsExterior 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 no

3governor closes and exhausts the air from above the unloader pistons. The unloader springs force the pistons upward and the inlet valves return to th

1. Ensure that the governor control line from the reservoir is located at or near the top of the reservoir. (This line, if located near the bottom of

31NOTES

HighSTART BASIC TESTIs this atransit vehicle, bulkunloader, or has morethan 5 axles?YES, this is a highair usevehicle.NO, this is a low airuse vehicle

Footnote 1: Note: Typical air dryer cartridge replacement schedule is every 3 yrs/ 300K miles for low air use vehicles and every year/100K miles for h

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. 1: O

35Technical Bulletin Bulletin No.: TCH-008-021 Effective Date: 11/1/92 Page: 1 of 2Subject: Air Brake System - Cold Weather Operation Ti

36Bulletin No.: TCH-008-021 Effective Date: 11/1/92 Page: 2 of 2High Duty Cycle Vehicles (City Transit Coaches, Refuse Haulers, Etc.) T

Technical Bulletin Bulletin No.: TCH-008-022 Effective Date: 1/1/1994 Page: 1 of 1Subject: Additional Cold Weather Operation Tips for th

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4DUTY CYCLEThe duty cycle is the ratio of time the compressor spends building air to the total engine running time. Air compres-sors are designed to b

BW1637 © 2008 Bendix Commercial Vehicle Systems LLC 6/2008 All rights reserved. Printed in U.S.A.40

5COOLINGAir fl owing through the engine compartment from the action of the engine’s fan and the movement of the vehicle assists in cooling the compress

6If a previously unturbocharged compressor is being turbocharged, it is recommended that the inlet cavity screen (238948) be installed with an inlet g

7DRY ELEMENT - PLEATED PAPER STRAINER Every two months, 800 operating hours or 20,000 miles whichever occurs fi rst, loosen the spring clip from the u

8AIR LEAKAGE TESTS Compressor leakage tests need not be performed on a regular basis. These tests should be performed when; it is suspected that disc

94. Remove the inlet valve stops (14), valves (17), valve seats (11), valve springs (12) and gaskets (10). It is recommended that a tool such as a J-