Air Supply for ARB Diff Locker & Tire
Inflation (4.0/4.6)
Hardy Neale's Approach
Introduction
Parts Required
Design and Procedure
Results
More Information
Introduction
A useful upgrade for serious off road work is an ARB air locker. This
requires an air supply, so on late model Range Rovers it is possible to
use the stock air pump rather than installing another one as is
necessary on most 4x4s. Hardy Neale took advantage of the occasion of
installing his locker to set up his system to supply on-board air for
tire inflation.
Hardy reports: "The ARB locker requires an air supply of no greater
pressure than
105PSI. As
the EAS runs up to 150PSI, some sort of regulator was required to
protect the locker and to supposedly stay within warranty
guidelines. Now
was also a good time to sort out some on board air using
existing EAS reservoir, so this is what I came up with..."
Parts
Required
The picture at top right shows some of the various
components Hardy used - clockwise from left:
6mm plastic T-piece
1/4" threaded brass T-piece (2x6mm & 1x1/4" fittings)
SMC regulator with gauge and 6mm fittings
1/4" fitted inflation valve (150PSI+)
2nd gauge
6mm fitting with 1/4 thread (for 2nd gauge)
Design and Procedure
"It
took some time to work out how best to route all the different air
lines and to locate all fittings. Using
a 6mm T-piece I intercepted the main supply line from EAS up near the
main valve block. The
new line then went to another T-piece, creating 2 additional supply
lines - 1 to main gauge and 1 to brass T-piece.The
brass T-piece was required to accommodate a 1/4" push in
fitting - the size of the line for the main inflation valve. The other
6mm line then went to the regulator.
NOTE:
Never fit 6mm line into a 1/4" fitting and never fit 1/4" line into a
6mm fitting - they are not interchangeable."
The pictures below show the general approach.
|
|
|
The light blue line is
for rear air locker (5mm) and dark blue line is
for main inflation valve.
The orange fitting is the ARB 5mm fitting.
Note 2 shiny bolts on
power steering fluid reservoir - later replaced.
|
Picture
showing location of brass T-piece within EAS container - no need to
mount on any bracket, sits there quite nicely.
|
Note in the above pictures you can see a
cluster of 4 external solenoids (to left of EAS valve
block in left hand picture and at top right in right hand picture).
This is for the systemHardy had installed earlier for cross linking
front and rear suspension in the same manner as the new Mk III Range
Rover. Note also various 6mm
T-pieces at valve block used for cross linking
suspension. Hardy toyed with using
these solenoids for rear locker
but soon realised the ARB 3 way solenoid is
required to properly de-activate diff lock.
"A previously unemployed
piece of hefty aluminium angle
loitering in my shed soon found itself a well
paid job. F
itted
hard against the radiator frame and held in place by slightly
longer bolts to power steering fluid reservoir, it supports the regulator, 2 gauges and
inflation valve assembly. The whole
assembly does flex
a little laterally - but this stems from the radiator
frame, not the installation method.
|
|
Installed Assembly.
|
Picture showing the actual tyre
inflator with 25' coiled hose
and simple lever style connector.
|
"In the picture above left, on the LHS is main inflation valve. This
can be used to de-pressurise and
re-pressurise EAS reservoir as well as just re-inflating
tyres!
LHS gauge shows the
pressure in EAS reservoir. Handy for monitoring
pressure when filling tyres. Picture current pressure is 135PSI.
RHS
gauge shows regulated pressure for air locker, set to 95PSI. Note
black locking knob on RHS to adjust pressure.
The ARB solenoid in the middle was a bit of an after thought. I was in
a hurry as I'd run out of time, but 6 weeks later the double sided
tape is still holding!"
Results
So
far I have not been 'let down' by the inflation system.
While
it's no powerhouse, the existing compressor & EAS
reservoir is adequate for 'topping up' tyre pressures after
partial reduction for rocks and sand etc.
If you have comments or suggestions, email
author John Brabyn
Last Updated 13 April 2005