P38 EAS Tyre Inflation & ARB Locker Air Supply

[Hardy]

I finally got around to taking pictures and writing a little story on my tyre inflation system and air supply for diff locker.
But alas - no pictures can be posted.
Am I missing something? I used to be able to upload pictures.
I've included the picture references anyway, so if you're interested I can forward them on to you.

The ARB diff 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 and compressor, so this is what I came up with...

pic1 shows some of the various components required - 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)

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 reservoir, 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 - an odd size and that 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.

pic2 shows the mess unfolding.
The light blue line is for rear air locker (5mm) and dark blue line is for main inflation valve.
The cluster of 4 external solenoids to left of EAS valve block is for cross linking front and rear suspension.
Note the orange fitting - ARB 5mm fitting.
I toyed with using these solenoids for rear locker but soon realised the ARB 3 way solenoid is required to properly de-activate diff lock.
Note also various 6mm T-pieces at valve block used for cross linking suspension.
Note 2 shiny bolts on power steering fluid reservoir - later replaced.
pic3 shows the location of brass T-piece within EAS container - no need to mount on any bracket, sits in there quite nicely.

A previously unemployed piece of hefty aluminium angle loitering in my shed soon found itself a well paid job.
Fitted 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. The whole assembly does flex a little laterally - but this stems from the radiator frame, not the installation method.
pic4 shows the installed assembly.
On 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 shows current reservoir pressure is 135PSI
RHS gauge shows regulated pressure for air locker, set to 95PSI. Note black locking knob on RHS to regulate pressure.
The ARB solenoid location (between gauges) 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!
pic5 shows the actual tyre inflator with 25' coiled hose and simple lever style connector.

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.
Best part is the comparatively low cost and relative benefits.

Regards,
Hardy

[wilsby]

Hardy, I'm contemplating doing something similar for inflating tires. No need for the ARB part, as I went with TrueTrac's.

Now, I always believed that the drier system was inadequate for anything but the almost closed system of EAS? Have you thought of fitting some kind of air drier after the compressor to protect the system from water?

[Hardy]

Nah, not really Wilsby.
Are you talking about improving the standard dryer set-up to further protect existing EAS or concerned about what effect my mods would have on air quality?

I haven't really studied the standard airline circuts that closely.
I just used the theory that if the air in reservoir is good enough for the EAS it'd be good enough for filling tyres.

It's air coming out, not going in.

Hardy

[RaginRover]

EAS pump is really quite a dry one, heaps dryer than other compressors
that I have had in cars.

I have some friends that have modified an EAS system and added a 100% duty cycle pump to work in to assist it to the system come up from dead flat. It works in conjunction with other pump from 0-100PSI then the EAS pump does the rest.

As for the drying an air compressor water seperator on the line running
down to the reserve tank. Cheap and simple

Tom

[wilsby]

Tom, thank's. I guess if you want to be really anal about it, the drier should be on the line from the compressor, trapping the humidity both when the air goes to the tank and when it goes directly to a tire.

Hardy, my concern is that when you start to tap the system for air for external use, the built in drier will be saturated in no time, hence the need for extra drier.