Check king pin wear
Lubricate upper coupler plate and king pin

X

Visually check tightness of all fasteners

X
X

Check all supports and braces
Notice

Annually

10K-25K Miles

5,000 Miles

Monthly

Dailey

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Weekly

Tank trailer should be inspected periodically to ensure it meets D.O.T.
requirements.
Refer to the D.O.T. Transportation of Hazardous Materials Handbook
(paragraph 177.824) if hazardous materials at to be hauled.

LUBRICATION & SERVICE
1. Manhole Cover-(Weekly)-check clamping device for proper cover closure; check gasket for damage. (Monthly)-Clean manhole gasket and
lubricate clamps.
2. Lights and Wiring-(Daily)-check all lights for proper operation. (Weekly)
-Check all connections. (Every 5000 miles)-Check for chafed or broken
wires.
3. Anti-Lock Brake System-(Daily)-Check for proper operation. Refer to
Anti-Lock System Maintenance Manual. (Every 5000 miles)-Adjust
brakes. (Every 10,000 to 25,000 miles)-Inspect linings, free-up brake
shoes and anchor pins.
4. Rear Structure-(Weekly)-Check bolts for proper torque (150 lb-ft)
5. Suspension-(Every 5000 miles)-Check for proper bolt torque. See page
48 for torque chart.
6. Tires-(Daily)-Check for proper inflation, cuts or other damage.
7.

Axles-(Weekly)-Check oil level and for leakage around oil seals. Check
pivot bolt connections for proper torque. (Every 5000 miles) Check axle
alignment to king pin.

8. Wheels-(Weekly)-Check lug nuts or bolts for proper torque. (Every
10,000 to 25,000 miles) Check wheel bearings. Tighten or replace as required.
9. Aeration -Clean or replace as required. (Every 2 years)
10. Piping-Check for loose clamps, damaged hoses or leaks. (Monthly) Perform general inspection.
11. Supports-(Monthly)-Lubricate; check mounting bolts for proper torque
(150 lb-ft).
12. Front Structure-(Weekly)-Check bolts for proper torque (150 lb-ft).

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LUBRICATION AND SERVICE (CONTINUED)
13. Upper 5th Wheel-(Every 5000 miles) Lubricate with multipurpose
grease.
14. Compressor or Blower-Service according to manufacturer’s recommendations.

GENERAL INSPECTION-AERATION SYSTEM
The following inspection should be performed monthly.
1. Check pressure gauges for accuracy.
2. Close manhole covers. Close all valves except aeration valves. Remove
dust cap from product line.
3. Start compressor (or blower) and pressurize tank until relief valve opens.
DO NOT EXCEED MAXIMUM OPERATING PRESSURE

WARNING
If relief valve does not open at pressure specified on valve, shut off
compressor or blower and correct the cause of the inoperative relief
valve.

NOTICE
Compressors can be severely damaged if operated at speeds and
pressures higher than rated and if the air filter is clogged. Check operating speed and pressure rating of the compressor to make sure it
is not running too high. See Manufacturer’s recommendations.

4. After tank is pressurized, close the aeration valves and shut off compressor blower. Tank pressure should remain relatively constant. If pressure
drops excessively, check for leaks in manhole cover, relief valve, blowdown
valve and tank proper. If none are found with the above inspection, check
for air leaks in the aeration, pressure control and product valves.

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5. When inspection is complete, open blowdown valve to exhaust the air in
the tank. Replace dust cap on product line. If one or more hoppers does
not discharge properly, and there are no leaks in tank or valves, the following service procedure is recommended.
1. Remove product from these sections.
2. Check aeration line for possible plug.
3. Check aeration device on interior of tank. Look for torn molded
neoprene cone (s), rotated wear plate (s) or plugged aerator housings (see figure 16). Replace as necessary.

Figure 16. Exploded View of Aerator

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BRAKES-MAINTENANCE & ADJUSTMENT
NOTICE
Refer to Anti-Lock Brake System Maintenance Manual for operational
check and service instructions.

The wheel brakes are equipped with slack adjusters for easy brake adjustment to compensate for brake lining wear. It is recommended that slack adjuster arm travel be held to a minimum for most efficient braking action. The
brakes should be adjusted when total arm travel reaches 1-1/2”.
To adjust brakes, depress lock sleeve on slack adjuster, then turn adjustment
screw as required. Make sure lock sleeve returns to lock position when adjustment is complete.
Every 5000 miles, the brake camshafts should be lubricated with approved
chassis lubricant. Every 10,000 to 25,000 miles, the brakes should be serviced as follows:
1. Remove wheels and hubs.
2. Inspect brake roller shafts, cam rollers, anchor pins, camshaft support bushings, spider bushings and camshaft for wear and replace
if necessary. Lubricate these parts with chassis lubricant upon reassembly.
3. Inspect brake linings for wear, loose rivets and any signs of grease
on the braking surface. Oil-soaked linings are not reusable and
must be replaced. Check to ensure that the linings have not worn
to the point that rivet heads are contacting inside surface of drum.
Reline or replace brake shoes if necessary.
4. Check inside surface of drum. Rebooting of drums is not recommended, as the strength of refaced drums is greatly reduced. If
drum is worn, replace it.
5.

Service the wheel bearings and seals if required. Reassemble
hubs and wheels.

48

WHEEL BEARINGS & SEALS
The wheel hub revolves around the axle spindle on two roller bearings. The
bearings are lubricated and the hub cavity is sealed against leakage by a seal
which rides around an axle ring on the spindle shoulder. Figure 18 illustrates
the bearing and seal arrangement.
Check oil level and for leaks around the oil seal at least once a week. If low,
refill hub to oil level line on hub cap. Heil recommends using 75W90 Synthetic Gear Oil. For best results and wheel end life, use only compatible lubricant
products.

Figure 18. Cross Section View of Wheel Hub
Wheel Bearing Adjustment
Bearing adjustment should be 0.001”-0.010” end play and a minimum of preload. Use the following procedure:
1. Tighten inner jam nut (figure 18) with a 12 inch wrench while
turning wheel in both directions until there is a slight bind which
indicates all bearing surfaces are in contact.

49

Wheel Bearing Adjustment (continued)
2. Back off inner jam nut 1/3 turn to allow the wheel to rotate freely.
3. Install washer and tighten outer jam nut.
4. Final bearing adjustment should be with 0.001” to 0.010” end
play. Tighten nuts at this position.

Figure 19. End Play Adjustment
Oil Seal Replacement
If oil leakage around the inner oil seal is noted, replace the oil seal (and axle
ring, if required) as follows:
1. Remove wheels and hub
2. Remove and discard old seal.
3. Inspect axle ring. If pitted or worn, replace as follows:
a. Remove old ring. Take care not to damage spindle.
b. Clean spindle thoroughly. Shoulder area must be smooth and
free from weld spatter and burrs.
c. If shoulder is not completely smooth apply sealer No. 2 to correct any defects and ensure an oil-tight fit.

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Oil Seal Replacement (continued)
d. Using axle tool, drive the axle ring firmly on shoulder.
Edge of axle ring must be parallel and flush with shoulder
face. Remove excess sealer, if used.
4. Install oil seal in wheel hub as follows:
a. Remove all burrs from inside hub bore.
b. If seal is not pre-coated with BLU-SEAL, or if wheel hub
bore is not entirely free of nicks or burrs, apply a thin coat of
sealer No. 2 to the O.D. perimeter of the oil seal.
c. Lay wheel down, brake drum up. Check to ensure that hub
cavity is clear of old grease, grit and metal particles-steam
clean if possible. Check bearing cones on spindle for proper
slip fit. Install inner bearing in hub bore. Place seal in starting position in bore.
d. Using hub tool and a hammer, drive seal squarely and
evenly into bore. Seal should bottom evenly all around
against bearing cup. DO NOT continue to hammer after seal
has bottomed evenly, as damage to the seal will result.
5. Coat seal lip and inside diameter of inner bearing cone, then install
wheel on axle. Take care not to damage seal during installation. If
wheel does not slip back in place easily, remove and check for burrs
or possible component damage.
6. Install outer bearing, jam nuts and washer. Adjust bearing preload (see Wheel Bearing Adjustment).
7. Install gasket and hub cap.
8. Refill hub with recommended oil. See Wheel Bearings and Seals.
1 to 1-1/2 pints are required per hub, depending on wheel well design. A minimum of 1 pint is required for proper lubrication. Allow
plenty of time for the oil to seep through the bearings.
9. Re-install vent plug.

51

WHEEL & TIRE MAINTENANCE
Proper tire inflation and correct installation of rims and wheels is essential to
safe, economical, trouble-free service.
Check tire pressures daily. Recommended inflation pressure is noted on VIN
Data Plate. DO NOT over-inflate tires, as this is a common cause of rim failures and accidents. Never run vehicle on one tire of a dual wheel assembly.
Loss of air in one tire of a dual set excessively overloads the other tire if the
vehicle is operated in this condition.
When checking tire pressures, visually check studs and rim for looseness,
cracks or other damage. Inspect tires for uneven wear, cuts, cracks, etc.,
which would render the tire unfit for further service. If the least doubt exists
as to the tires’ serviceability, replace the tire.

DANGER
Be extremely careful when working with tires and wheels. Tires and
wheels can come apart with explosive force. Never attempt to disassemble a wheel with an inflated tire mounted on it.

Check wheel lug torques at least once a week. Recommended torque for the
¾-10 lug nuts on spoke wheels is 450-500 lb-ft (dry).

52

NOTICE
Insufficient mounting torque can cause rim slippage, resulting in broken valves, worn parts and damaged tires. Excessive mounting
torque can cause damage by stripping studs, collapsing spacer bands
or forcing rims into an out-of round condition.

Figure 20. Disc Wheel Installation
Recommended Installation Procedure-Disc Wheels
1. Check all parts for damage, including wheels and rings. Insure that all
studs, nuts and mounting faces of hub and wheels are clean and free from
grease. Replace any defective parts.
2. Mount inner dual wheel over studs, being careful not to damage stud
threads.
3. Mount the outer wheel, being careful not to damage stud threads and
hand tighten wheel nuts.
4. Tighten nuts fully, using a crossing pattern as shown in figure 20. Be
sure to tighten nuts only to the recommended torque. The correct wheel
nut torque is 450-500 lb-ft (dry).

53

NOTICE
Insufficient mounting torque can cause wheel shimmy, resulting in
damage to parts and extreme tire tread wear. Excessive mounting
torque can cause studs to break and discs to crack in the stud hole
area.

AXLE ALIGNMENT
Improper axle alignment will cause dog-tracking and excessive tire wear. To
check alignment of axles to king pin, use the following procedure:
1. Set empty trailer on level smooth surface, disconnect trailer brakes and
bleed air tank.
2. Rock trailer back and forth for a distance of approximately 10 feet to relieve any binding in brakes or suspension bushings.
3. Tow trailer straight forward for a distance of approximately 30 feet. Stop
trailer with tractor gears or tractor brakes only.
4. Disconnect tractor from trailer and ensure suspension ride height is
properly adjusted.
5. Adjust landing legs to level trailer and set upper coupler to the correct
ride height.
6. Do not remove wheels, but remove all hub caps and install axle center
extensions. Use suitable kingpin jack or center extension to insure a clear
path from the kingpin centerline to the axle center extensions.
7.

Measure from kingpin extensions to both front axle center extensions.
This distance should be the same on both sides (A = B).

8.

If not, remove and install new pivot bolts leaving them loose enough to
adjust axle to square with the kingpin. Make sure there are no obstacles
in front of wheels during alignment.

Notice
Pivot bolts must be replaced during realignment of the suspension.

54

Axle Alignment (continued)
9.

Measure from front axle center extensions to rear axle center extensions.
This distance should be the same of both sides (C = D). If not, remove
and install new pivot bolts leaving them loose enough to adjust rear axle
to parallel with front axle. The suspension should now be in proper alignment with the kingpin.

Figure 21. Trailer Alignment
®

10. The QUIK-ALIGN style pivot connection uses two flanged collars inserted into slots on each side of the frame bracket (figure 23). The eccentric
collar on the outboard side of the frame bracket is used to adjust the position of the axle during an alignment. The alignment guides on the side
of the frame bracket limit the eccentric collar to rotational movement in
the frame bracket slot. Rotating the eccentric collar clockwise causes the
axle to move forward. Rotating the eccentric collar counterclockwise causes the axle to move rearward (figure 22). The maximum range of adjustment is ±45 degrees from the 12 o’clock position.

55

Figure 22. Quick-Align Operation
11. Using an E20 Torx socket, tighten the shear-type bolt axle pivot connection until the Torx head shears off. This ensures the proper torque of 550
ft. lbs. (±45 ft. lbs.). Pivot bolts must be replaced when trailer is aligned.
DO NOT attempt to reuse old pivot bolts. Assembly of pivot connection
shown in figure 23.

Figure 23. Pivot Connection Assembly
12. Connect tractor to trailer and connect trailer brakes on the lot. Make four
or five tight figure eights and an equal number of “panic” brake stops.
Bring trailer back into shop and check axle alignment. If axles are not in
proper alignment, check for loose or worn bushings and bearings, loose or
broken hangers, cross members, side rails or kingpin.

56

Trailer Suspension System
Components and General Maintenance Guidelines
HEIGHT CONTROL VALVE - The height control valve on the trailer air suspension automatically responds to the relative position of the axle and vehicle
frame. It meters air into or out of the air springs. Variations in load or temperature only affect the adding or exhausting of air. The trailer air suspension
is a mechanically stable suspension, only one height control valve is necessary.

Figure 23. Suspension Height Control Valve
When the actuating lever of the height control valve moves up, the valve
opens and connects the air supply to the air spring. When the actuating lever
moves down, the valve shuts off the air supply and opens the exhaust port to
vent excess air from the air springs. A check valve prevents the loss of air
spring pressure if the air supply fails. In the central position, air does not flow
in or out of the air springs.
RIDE HEIGHT ADJUSTMENT
1. Connect the vehicle to a compressed air supply with approximately the
pressure of the normal supply system.
2. Ensure the inflation of the air springs.

57

Trailer Suspension System
Components and General Maintenance Guidelines
3. Measure the ride height by using this method:
a. Measure from the underside of the trailer frame to the top of the
axle as shown in figure 24 below
b. Add half the diameter of the axle to the measurement

Figure 24. Measuring Ride Height
4. Raise or lower the trailer as necessary, so it is at the designed ride height.
5. Once the trailer is set to the correct designed ride height, set the HCV lever
to the neutral (central) position.
Notice
When adjusting the height control valve, block the tires and release
the trailer brakes. The axle must rotate freely to avoid a false reading.
Some height control valves have very small openings and a time delay of as much as 15 seconds. Allow sufficient time for the system to
react to the adjustment. The response time will appear to be lengthy,
but be patient.
6. Adjust the HCV linkage to fit between HCV lever and lower linkage attachment.
7. Once set to the designed ride height, test drive the trailer. After the test
drive, check the ride height to assure an accurate adjustment.

58

Trailer Suspension System
Components and General Maintenance Guidelines
AIR SPRINGS - Air springs will last almost indefinitely in most applications.
However air springs will fail quickly when rubbed, scuffed, or punctured. If an
air spring fails, the trailer will settle on the internal rubber bumpers, so you
can proceed to the nearest service facility at a lower speed. You should try to
determine the cause of a failure, so you can avoid a costly repeat of the problem.
Air Spring Replacement
To replace an air spring, follow these steps:
1. Exhaust all air from the suspension system.
2. Raise and support the vehicle in a safe manner.
3. Unbolt the air spring.
4. Disconnect air-supply lines.
5. Replace the air spring.
6. Bolt the air spring in place.
7. Connect the air-supply lines.
8. Lower the trailer to the ground.
9. Supply air to the suspension system.
SHOCK ABSORBER - Shock absorbers absorb energy to prevent suspension
oscillation. Shock absorbers are also rebound stops in most air suspensions.
The shock absorber limits the stroke of an air spring, which prevents the air
spring from being pulled apart.
To remove a shock absorber, follow these steps:
1. Remove the end fasteners.
2. Insert the new shock absorber.
3. Secure with correct size locknut and bolts.
4. Torque fasteners to specification.

59

Trailer Suspension System
Components and General Maintenance Guidelines
PIVOT CONNECTION - A correct pivot connection is crucial to the life of the
suspension. The pivot fastener must continually provide a sufficient clamp
load through the bushing to prevent premature suspension failure. Hendrickson INTRAAX suspension systems come equipped with QUIK-ALIGN pivot connection hardware. The hardware consists of a specially plated shear bolt to
ensure a proper clamp load, (550 ft-lbs, H-45 torque).
NOTICE
Failure to properly torque the pivot bolts may result in loss of warranty coverage.
TRI-FUNCTIONAL BUSHING - have unique properties that will provide
years of maintenance-free service. The TRI-FUNCTIONAL BUSHING (located
at the suspension pivot connection) provides a resilient connection that allows
an axle to walk without excessive flexing. The TRI-FUNCTIONAL BUSHING, in
conjunction with the rigid axle connection, results in a roll-stable suspension
design that resists trailer lean independent of the air spring loading. Reference Hendrickson service guide L427 for bushing replacement procedures.

Figure 25. Pivot Connection Assembly

60

TORQUE SPECIFICATIONS
RECOMMENDED SUSPENSION TORQUE

RECOMMENDED WHEEL TORQUES

61

REPORTING SAFETY DEFECTS
If you believe that your vehicle has a defect which could cause a
crash or could cause injury or death, you should immediately inform
the National Highway Traffic Safety Administration (NHTSA) in addition to notifying Heil Trailer International.
If NHTSA receives similar complaints, it may open an investigation,
and if it finds that a safety defect exists in a group of vehicles, it may
order a recall and remedy campaign. However, NHTSA cannot become involved in individual problems between you, your dealer or Heil
Trailer International.
To contact NHTSA, you may either call the Auto Safety Hotline tollfree at Monday-Friday 8am to 8pm at (888) 327-4236 , TTY: (800)
424-9153, or file and online form at www.nhtsa.gov. You can also obtain other information about motor vehicle safety from the Hotline.

62

Use only Genuine Heil parts. For trailer parts and
technical information, please contact.

Heil Tank Service at 800-428-7101

Heil Part Number
9544-0015

63