BENDIX TU-FLO 400-500-1000 AIR COMPRESSOR Bendix Air System Inspection Cup Basic Test Information

Appendix A: Information about the BASIC Test Kit (Bendix P/N 5013711)

Service writer records info - including
	days
the number of days since all air tanks
were drained - and fills out symptom
checklist. Technician inspects items.

START BASIC TEST

Park vehicle on LEVEL ground.

Chock wheels, drain air from system.

Bendix® Air System Inspection Cup (BASIC) Test Information

Drain contents of ALL air

tanks into BASIC cup

Is there	YES
less than one
unit of liquid?
NO

Vehicle OK. Return vehicle to service.

END TEST

Is
there more		Cloudy emulsion mixture
than one unit of:	YES
• water, or
• cloudy emulsion
mixture?
NO, only oil.

YES, this is a high		Is this a		NO, this is a low air
	transit vehicle, bulk
air use					use vehicle.
	unloader, or has more
vehicle.
		than 5 axles?
Find the point on the label				Find the point on the label
where the number of oil units			where the number of oil units

	Is this vehicle
YES	being re-tested (after	NO
	water, etc. was found
	last time?)

High	meets the number of days*	Low	meets the number of days*
	since the vehicle's air tanks		since the vehicle's air tanks
	were last drained.		were last drained.

Go to the Advanced Troubleshooting Guide to find

Change air dryer cartridge**

High

Is the point above

the HIGH Air Use

line on the NO cup?

High	YES
Test for air	Use Test 2:
leakage
	Air Leakage

	Is the
	point above
	the LOW Air Use
	line on the
	cup?
	Low
	NO
Low	YES
	Vehicle OK.
	Return vehicle to
	service.

reason(s) for

presence of water

END TEST

END TEST

Test for air

leakage Use Test 2:

Air Leakage

Re-test with the BASIC Test after 30 days***

END TEST

Does	YES	Repair leaks and
the vehicle have
		return vehicle to
excessive air
			service
leakage?
NO	NO (did not know
Was	when last
the number of	drained)		Re-test with the
days since last			BASIC Test after
draining			30 days***
known?

YES, number of days was known (30 - 90 days)

END TEST

END TEST

* If the number of days since the air tanks were drained is

unknown - use the 30 day line.

** Note: Typical air dryer cartridge replacement schedule is every

3 yrs/ 300K miles for low air use vehicles and every year/100K

miles for high air use vehicles.

*** To get an accurate reading for the amount of oil collected

during a 30 day period, ask the customer not to drain the air

tanks before returning. (Note that 30-90 days is the

recommended air tank drain schedule for vehicles equipped

with a Bendix air dryer that are properly maintained.) If, in cold

Replace the Compressor. If under warranty, follow standard procedures.

If, after a compressor was already replaced, the vehicle fails the CompressorBASIC test again, do not replace the compressor**** - use the

Advanced Troubleshooting Guide to investigate the cause(s).

weather conditions, the 30 day air tank drain schedule is longer

than the customer's usual draining interval, the customer must

determine, based on its experience with the vehicle, whether to

participate now, or wait for warmer weather. See the cold

weather tips in Bulletins TCH-008-21 and TCH-008-22 (included

on pages 35-37 of this document).

END TEST	****Note: After replacing a compressor, residual oil may take a
	considerable period of time to be flushed from the air brake system.

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