Installing the PURest
IMPORTANT CAUTION
1. Park the vehicle on a level surface, apply the
parking brakes and always block the wheels.
2. Stop the engine when working around the
vehicle.
3. Make certain to drain the air pressure from all
reservoirs before beginning any work on
the vehicle.
4. Following the vehicle manufacturer's
recommended procedures; deactivate the
electrical system in a manner that removes all
electrical power from the vehicle.
5. When working in the engine compartment, the
engine should be shut off. Where
circumstances require that the engine be in
operation, extreme caution should be used to
prevent personal injury resulting from contact
with moving, rotating, leaking, heated or
electrically charged components.
6. Never connect or disconnect a hose or line
containing pressure. Never remove a
component plug unless you are certain all
system pressure has been depleted.
7. Never exceed recommended pressures and
always wear safety glasses.
8. Do not attempt to install, remove, disassemble
or assemble a component until you have read
and thoroughly understand the recommended
procedures. Use only the proper tools and
observe all precautions pertaining to the use of
those tools.
9. Use only genuine Haldex replacement parts,
components and kits. Replacement hardware,
tubing, fitting, etc should be of equivalent size,
type and strength as original equipment and be
designed specifically for such applications and
systems.
10. Components with stripped threads or
damaged parts should be replaced rather than
repaired. Repairs requiring machining or
welding should not be attempted unless
specifically approved and stated by the vehicle
or component manufacturer.
11. Prior to returning the vehicle to service, make
certain all components and systems are
restored to their proper operating condition.
General
The vehicle installation guidelines presented in the
Application Schematic apply to all PUR
est
Air Dryer
installations. Determine your system configuration
and plumb accordingly. Vehicles with the Holset
Type-E or QE compressor require the PUR
est
with
the Holset feature.
Mounting on Vehicle
1. Locate with sufficient space to facilitate service
& visual access.
2. Mount away from direct tire splash.
3. Brackets, Fittings and Lines to be mounted in a
protected area.
4. Exhaust port downward.
5. Mount in area to avoid excessive heat.
6. Rigid mount to avoid excess vibration.
7. Line from compressor to PUR
est
should have
continuous downward slope and no dips.
8. 90° Fittings should be avoided.
9. Not to exceed 15° inclination.
10. Maintain a minimum of ½" above the dryer for
access to the desiccant cartridge.
11. The dryer is equipped with an integrated
mounting bracket. The enclosed template is to
be used to drill three (3) 9/16" holes. If the
dryer is to be bolted directly to the frame or
support member, check vehicle manufacturer’s
recommendations.
12. The universal mounting bracket can be used to
simplify most change-overs.
13. Install the dryer using the enclosed ½" bolts.
Tighten to 45-55 ft-lb.
Heater Connection
1. Locate a circuit with the correct voltage that is
"hot" when the ignition is "ON". The current
draw is 8 amp@12V; 4amp@24V. A
10-15amp fuse is recommended in this line.
Connect one heater lead to this wire.
2. Connect other lead to a good ground on
vehicle chassis or electrical junction box.
