How strong is my trucks air compresor?

The truck's air compressor is probably going to have a higher cfm rating than any "affordable" compressor you'd buy for your garage. The only thing it really lacks is capacity, but when most of the air tools you'll be using are in the 4-6 cfm range, it'll have no problem keeping up...especially if you idle up a little while you're using the tools.

 

Any truck compressor now a days is going to be at least 10cfm. the bendix BA-921 on most detroit and accert cats is 15.6CFM at 1250RPM. it should handle a small impact no problem. just give the systema chance to catch up periodically to allow the dryer to purge to prevent moisture from getting into the tank.

 

If you're going to work on your truck you really ought to invest in a good compressor they're not that expensive.

 

It'll work, but it will be slow, the tanks will drain fast with a big tire gun. I have never seen anything published other than free flowing CFM from a truck compressor. The popular Tu-flow 550 is a little over 13 CFM, but that is at 1250 RPM (compressor) and no load. It also has a 25% duty cycle. Pushing the duty cycle limits makes it run hotter and reduces it's life. Hotter also makes more condensation which can overwelm the air dryer. If you start getting excess water in the wet tank, your probably pushing the compressor to hard.

It's OK for emergency or other temporary solutions, but a decent shop compressor should be in your plans if you want air often.

 

I've got an 80 gallon compressor at the house, but I carry a 1/2" gun, 3" cutoff tool, and a drill that all run off the truck's air if I'm NOT at home when stuff happens.

 

I have a 60 gallon propane tank that I have used to run an 1"tire impact with using truck glad hand air, Accerts may be able to produce the advertised CFM under boost, but with no load on the engine the rate is a lot lower. I have a big guage on the tank so that I can make sure the system cycles the dryer, and to be able to start using air just before the compressor kick out. If the studs/nut were cleaned and covered, the system will pop 10 nuts off in one shot.

 

the cfm output of all of our compressors is naturally aspirated. under boost the BA-921 produces closer to 20cfm of air for the single cylinder on the accerts .

 

Actual compressor CFM doesn't change, they are positive displacement compressors. What changes is the air pressure in at the inlet, this makes a more dense inet charge, not a bigger one. The compressor still pumps the exact same volume of air per stroke. That inturn would increase output CFM at a given pressure. Those #'s are pretty meaningless though. What matters is CFM output at 90 psi, where air tool consumption is rated. For most trucks, that is less than most inexpesive home air compressors.

With atmospheric pressure at the compressor inlet, pump 1 cubic foot of air into a tank that will increase pressure to 90 PSI above atmospheric. You flowed 1 cubic foot in, but out is much smaller (compressed to 90 psi). Another way to look at it is (assuming everyting is 100% efficient and equal), a compressor that could output 5 CFM at 50 PSI, would only output 2.5 CFM at 100 PSI.

 

Okay for you guys running air tools off your trucks compressor and truck's air tanks. I want to setup a cheap emergency air tool kit. Couple questions:

My truck already has 1/4 inch NPT threaded bleeder valves in both tanks. What size quick connect fitting is coming off the air tanks on your truck? Did you use a 1/4 inch to 3/8 inch coupler? Does going up in size matter? What size air line are you using? Whats size fittings are on the line ends and impact gun? Are you using a 3/4 inch impact?

If anyone could give me a quick run down of the setup they have and the size of fittings and air lines I'd like to set this all up, hopefully, with just one run to home depot. LOL