I am wanting to build an air suspension and would like the ability to fill tires and run tools. I was told that trucks like small Freightliners and buses with air brakes have an engine mounted air compressor. Can anyone confirm this and has anyone used one in a pickup?

 

they do have them. I don't recall how they work, but i looked into it before and if i recall correctly it would take some work to make it function. I went down the same road, never did the air suspension, but decided an onboard 12 volt system would be better.

 

my freind used the stock ac compresor and made a oil reclaimer to recirculate the oil it works good and he has 10 years on compressor. but dont try if you are not in to fabricating.

 

I made my own setup for my rock crawler with a York a/c compressor. It's a 10.3 cubic inch twin cylinder pump, and it out performs most home size compressors. I had to fab the bracket, but that was fairly simple. Get it lined up with the crank pulley or you'll eat belts though!
Plumbing was simple. Ran the discharge through a oil/water separating filter, past a pressure switch, through a check valve, and to a tank under the rear.
Electrical was even easier. Run power through a switch on the dash to the pressure switch, then to the clutch on the pulley.

If you want to spend a load on a simple system, take a look here:

::Kilby Enterprises::

Otherwise, get the pump from a wrecking yard, and make your own. I have less than $200 in my complete setup, and have been using it trouble free for nearly a decade.

 

the engine mounted air compressers are a pump mounted on the engine and are powered by the engine. i work on macks and they are bolted on the backside of the block on the passenger side. i dont think they would work on our trucks but i could be wrong

 

iv read in an old chevy truck tuning handbook that you can use old a/c compressors as air compressors, you can buy the pumps from salvage yards for next to nothing, even if the pump is "bad" its normally just because they leek a little which isn't acceptable for a closed a/c system but would be fine to fill a tank of compressed air. even a really shitty a/c compressor will produce around 150psi, a good one will make around 200 if i remember correctly.

 

I have an engine mounted air compressor as my engine came out of a Ford CF8000 cab over box truck with air brakes. The compressor mounts to the timing gear case in place of the vacuum pump. Mine is a two cylinder Bendix unit with a Vickers hydraulic pump for a power steering pump mounted to the tail end of the compressor. Single cylinder compressors are available too. I love mine, it will charge my tanks to 120 psi in a heartbeat. The only downside is that using the factory Cummins mounted compressors robs you of the Dodge vacuum pump for all the vacuum accessories, like HVAC controls and the brake booster in the case of my '93 Ford. So, yes, there are factory Cummins compressors out there, although they are a little tricky to come by. I personally found two of them on Ebay the other day; one was a two cylinder Bendix and the other was a single cylinder Bendix... Just my $.02...

 

If you can find one from an old tire service truck they have dual cylinder ones also that put out a lot more volume than the single cyl. big rig ones and they're belt driven also, or they have ones that are pto driven but they take up more room and couldnt fit underhood.