BENDIX RESERVOIRS Guide

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®
RESERVOIRS
SD-04-400
TYPICALSINGLECOMPARTMENTRESERVOIR
DESCRIPTION
The reservoir is a storage tank; its function is to provide a
volumeofcompressedairforbrakingwhichwillbeadequate
in relation to the volume used by the brake chambers and
auxiliary devices. Reservoirs also provide a location in the
systemwheretheair,heatedbycompression,maybecooled
andthe water vaporcondensed.
Bendix®reservoirsarebuiltinaccordancewithSAEStandard
Air Brake Reservoir Test Code and Inspection Procedure
SAEJ-10-a.They aremadefromsteel sheet, withstamped
headsandrolled shells. Theseamsareelectrically welded,
andeachreservoirisinternallycoatedforcorrosionresistance.
Each reservoir is tested at 300 PSI hydrostatic pressure.
Reservoirsaresuppliedinvariouspipeferrule arrangements
and lengths and in diameters from 3-1/2" to 14" having
various volumes from approximately 100 cubic inches to
7600 cubic inches for tractors and trailers. All ferrules are
tapped to SAE dryseal pipe thread standards.
Reservoirsarealsosuppliedindoubleandtriplecompartment
configurationsandin some casesincludeanintegral check
valve between compartments in a double compartment
reservoir.Figure1illustratesatwocompartmentreservoir.
Two styles of check valves are shown in Figures 2 and 3.
Figure 3 is the current design.
OPERATION
Thereservoirsinan airbrake systemprimarilyservetostore
energyin theformofcompressedair.Theyalsoperform the
lessobvious function ofprovidinga meansofcooling theair
asdeliveredfromthecompressor and thereby condensing
water vapor into a liquid as well as collecting oil passed by
thecompressor.Thiswaterand oil collectsasanemulsion;
thegreatestamountinthereservoirnearestthecompressor.
It should be drained off either manually or by means of an
automaticdraindevice.
OPERATION OF INTEGRAL CHECK VALVE
The integral check valve provides a one-way passage of
airfromtheupstreamcompartment to the downstream.
This check valve may serve to meet the legal requirement
for a check valve to protect the service brake system in
case of failure in the compressor, discharge lines or first
reservoircompartment.
PREVENTIVE MAINTENANCE
Allreservoirsshouldbedraineddaily.If an automatic drain
deviceisused,itshouldbe checked periodically for proper
functioning. If an air dryer or aftercooler is used, the
reservoirsshouldbe manually drained periodicallytoverify
theproper function of the drying device. Reservoirs, which
have collected a considerable oily emulsion, should be
drained by opening a drain cock and allow to drain until all
drainagestops.
MAINTENANCE OF THE INTEGRAL CHECK
VALVE
Every six months, 1,800 operating hours or 50,000 miles
the check valve on the two compartment reservoir should
betestedforleakage,asoutlinedbelow,and parts inspected
for damage or deterioration and replaced if considered
unserviceable.
OPERATING AND LEAKAGE TEST FOR TWO
COMPARTMENTRESERVOIRCHECK VALVE
1. Determinethedirectionof the air flow.
2. Build up system air pressure to governor cut-out and
turn off engine.
3. Completely drain compartment #1 (see Figure 1).
NOTE: It may be necessary to remove automatic drain
device if so equipped.
4. To determine pressure retention in #2 compartment,
perform one of the following tests:
a. Check dashgauge (ifconnected to#2 compartment).
b. Apply service brake (if supplied from #2
compartment).

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FIGURE1 - TWOCOMPARTMENTRESERVOIRWITHCHECK VALVE
c. Momentarilyopendraindevice on #2compartment.
Do not completely drain #2 Compartment.
5. Apply a soap solution to the drain ferrule #1
compartment.Aslightbubble leakage is permitted.
If #2 compartment fails to hold air pressure or if excessive
leakage is evident at the drain ferrule of #1 compartment,
the check valve should be inspected for serviceability and
its parts replaced if necessary.
DISASSEMBLY
GENERAL
There are two types of two-compartment reservoir check
valvesandtheyare;
1. The old ball style check with a removable seat and a
seat spring (see Figure 2).
2. The new flat style that has a non-removable stainless
steel seat (see Figure 3).
Both types of check valves are located in a housing (large
ferrule)withacapnut cover. Theyaregenerallylocatedon
top of the reservoir shell.
DISASSEMBLY OF THE BALL STYLE CHECK
VALVE (FIGURE 2)
Block and hold vehicle by means other than air brakes.
Completely drain compartments #1 and #2. Remove cap
nutandcapnuto-ring.Removecheck valveandcheckvalve
spring. Remove seat spring. With a hook or similar device,
carefully remove the check valve seat and its
o-ring so as not to mar or scratch it.
DISASSEMBLY OF THE FLAT STYLE CHECK
VALVE (FIGURE 3)
Block and hold vehicle by means other than air brakes.
Completelydraincompartments#1and#2.
Removecapnutand cap nut o-ring.
Removevalvespring.
Removevalve andvalve guide.
CLEANING AND INSPECTION
Wash all metal parts in a good cleaning solvent and dry
them thoroughly. All rubber parts should be wiped clean.
Inspectsprings fordistortion,corrosion, andcracks.Inspect
valvesandvalveseatsfor nicks, cuts and burrs. Inspect all
rubberparts forswelling anddeterioration.Replaceorrepair
as necessary.
CAP NUT CAP NUT
GROOVEIN
CAP NUT
O-RING
VALVE
SPRING
GUIDE
CHECK
VALVE
VALVE
SPRING
O-RING
SEATSPRING
CHECKVALVE
O-RING
SEAT
SERVICEEACH50,000MILES
OR EVERY 6 MONTHS WITH:
FIELD MAINTENANCE KIT 282350
CONSISTING OF:
1 - CHECK VALVE
1 - GUIDE
1 - SPRING
1 - O-RING COMPARTMENT 1 COMPARTMENT 2
FIGURE 3 FIGURE 2

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ASSEMBLY
GENERAL
Beforeassembly,theo-rings shouldbecoated with silicone
lubricant BW-650-M Bendix pc. number 291126.
ASSEMBLYOF THE BALLSTYLECHECK VALVE
Replaceseato-ring and press seatintoshell.Replace seat
spring.Installcheck valve and valve spring.Replaceo-ring
on cap nut and install and tighten cap nut.
ASSEMBLY OF THE FLAT STYLE CHECK VALVE.
Replacevalve guideonvalveand installvalve.
Installvalve spring.
Replace o-ring on cap nut and install and tighten cap nut.
TEST
Perform tests as outlined in “Operation and LeakageTest”
section.
INSTALLATION
Reservoirsshouldbesecurelymountedwheretheywill be
protected against outside damage and so they will not
vibrate or move during normal operation of the vehicle. A
vibrating reservoir usually causes broken tubing lines.
Theyshouldbe the low point intheairbrake system and all
lines connected to them should drain toward the reservoir.
Thepipetapped openings inthereservoirshould not under
any circumstances be reduced in size from original
installation.
A drain cock or draining device must be installed in the
bottom connection of every reservoir and, in the case of
thetwo-compartment reservoir, in each compartment.
The first reservoir or first compartment must be protected
byinstallingasafetyvalve.
MINORREPAIRS
Minor repairs to the reservoir consist of examining the
reservoir mounting and the inspection of the outside for
corrosion or damage. The outside should be kept painted
to prevent the possibility of corrosion causing a failure.
MAJORREPAIRS
Repairs involving welding should never be performed on
reservoirs. If a reservoir has been damaged so as to be
unfit for use, it should be replaced with a new one.
In exceptional cases where the inside of a reservoir has
become excessively coated with sludge which cannot be
drainedoff, itissometimesadvisabletoremoveit andclean
withasolvent,steam,orwater. If a solvent is used to clean
thereservoir,thereservoirshouldbethoroughlyaeratedbefore
reinstalling.
WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURY OR DEATH:
When working on or around a vehicle, the following
general precautions should be observed at all times.
1. Park the vehicle on a level surface, apply the
parking brakes, and always block the wheels.
Always wear safety glasses.
2. Stop the engine and remove ignition key when
working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
enginebeinoperation,EXTREMECAUTIONshould
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.
3. Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended
procedures. Useonlythepropertoolsandobserve
all precautions pertaining to use of those tools.
4. If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure
from all reservoirs before beginning ANY work on
the vehicle. If the vehicle is equipped with an
AD-IS™airdryersystemoradryerreservoirmodule,
be sure to drain the purge reservoir.
5. Following the vehicle manufacturer’s
recommendedprocedures,deactivatetheelectrical
systeminamannerthatsafelyremovesallelectrical
power from the vehicle.
6. Never exceed manufacturer’s recommended
pressures.
7. 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 pressure has been depleted.
8. Use only genuine Bendix®replacement parts,
components and kits. Replacement hardware,
tubing, hose, fittings, etc. must be of equivalent
size, type and strength as original equipment and
bedesignedspecificallyforsuchapplicationsand
systems.
9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
notattemptrepairsrequiringmachiningorwelding
unless specifically stated and approved by the
vehicle and component manufacturer.
10. Prior to returning the vehicle to service, make
certainallcomponentsandsystemsarerestoredto
their proper operating condition.
11. Forvehicleswith AntilockTraction Control(ATC),
the ATC function must be disabled (ATC indicator
lampshouldbeON)priortoperforminganyvehicle
maintenance where one or more wheels on a
drive axle are lifted off the ground and moving.

4BW1590 © 2004 Bendix Commercial Vehicle Systems LLC All rights reserved. 8/2004 Printed in U.S.A.