BENDIX TCH-001-045 Manual Do Utilizador

General Comments
Some oil carryover from the air compressor into the air brake system occurs as a normal part of all air compressor
operation. Compressors require oil carry over to lubricate the compressor’s valves and rings.  It is typical to find
some presence of oil at the inlet and discharge ports of the air compressor. Oil present at the exhaust of drain
valves, air dryers or aftercoolers is normal and indicates that these components are functioning properly,
removing contaminants from the system.

Vehicles equipped with a desiccant type air dryer that incorporates a filter (separator) for removing oil from the
air will normally minimize oil passed through to the reservoir. The oil collects in the air dryer with condensed
moisture and is periodically purged. Often, the routing or location of the air dryer exhaust port can amplify
concerns about oil passing, depending on where the purged oil / water mixture is expelled on the vehicle, e.g. on a
fender or onto a fuel tank. This can mistakenly be identified as “problem” oil passing, when in actuality the air
dryer and compressor are functioning properly.

Vehicles may be equipped with condensing type aftercoolers or drain valves instead of an air dryer. These devices
have little or no affect on preventing oil or water from being passed through the system and into the reservoir.

If after reviewing these general comments excessive oil passing is still suspected proceed to Step 1.

Step 1: Reservoir Draining
If excessive oil is passing from the air compressor, the air dryer filter element and desiccant may become
saturated. One of the first signs of oil saturated filter element or desiccant cartridge is moisture appearing in the
reservoirs.

The first step in determining if a compressor is passing an excessive amount of oil is to drain the reservoirs and
monitor the amount of water and/or oil removed.

Check reservoir drain valves to ensure that they are functioning properly. It is recommended that the vehicle
should be equipped with functioning automatic valves or have all reservoirs drained to zero (0) psi (0 kPa) daily
or optimally to be equipped with a desiccant type air dryer prior to the reservoir system.

If when draining the reservoirs there is an absence of water and/or oil, the compressor and all compressor support
systems are operating properly and there is no need to proceed further. If the expulsion from the dryer purge
occurs in a location such that it affects vehicle appearance, reroute the purge.

If water and/or oil are present, and the duration since the last reservoir draining is known and consistent with
Table A, go to Step 2.

If the reservoirs have not been drained according to Table A, follow the suggested frequency for two cycles.  If at
the end of the second cycle, water and/or oil are drained, further investigation is needed.  Proceed to Step 2.