It is a pressurized system and you will need an R134A fitting, regulator and assorted pressure fittings and connectors along with a bottle of high pressure nitrogen gas. After you depressurize the system, introduce an ounce or two of brakeline antifreeze into the reservoir and then repressurize to 175 psi with clean dry nitrogen.Do you know of an easy way to introduce the antifreeze into the system?
I guess the answer is there is no “very easy” way without some tools and equipment. The pressure fittings and the nitrogen gas bottle from a welding gas supplier are a modest cost, BUT you need to know your way around this type of equipment.
Words of caution:
Heavy truck airline brake systems have a way to drain the methanol once it has scavenged as much moisture and water vapour as it can hold. The RAM pressure reservoir consists of two relatively shallow bottles laying across the frame rails. There is no direct way to drain any water saturated brake line antifreeze trapped in the system - and no place to tap and thread a fitting to put a drain in. Also, to access and remove the reservoir bottles you need to lift the truck bed.
There is also a small risk of a liquid entering your compressor, which is why you need to “Limit” the amount added.
Use only brake line antifreeze, since it has additives to minimize the corrosive effects of the methanol on certain types of plastics and rubber. The majority of the RAM air ride system short of the stainless steel pressure reservoir bottles is made of a variety of plastic, rubber and related compounds including the valve body o-rings.