ELLSSUU

My Wrenching ability = low, but I'm learning

Having a shop replace my rear shocks = moderatly expensive

Me doing them plus buying a cheaper air compressor (harbor freight) = about the same price, plus I get to keep the air compressor for things like CV Axles etc.

I'm looking for advice, guys? Which to choose? Also, what specs aircompressor for this type of work?

Horse Power: 2
Power supply: 115
Amp draw: 11
Air Delivery:
@ 70 PSI: 3.4 CFM
@ 115 PSI: 2.6 CFM
Lubrication: oil
Tank configuration: horizontal
Tank size: 6-1/2 gallon

Will that work?

ninefiveone

What do you need the air compressor for? I'm not well versed with air tools but get the impression that they're poor at applying the proper torque to things. Since the rear arms are aluminum, I'd be particularly careful when you torque them down. I know the rear shock bolts can be particularly stubborn to remove (I've been in there a few times). A breaker bar and a jack will do the job nicely to remove them.

The CV's and those cheesehead bolts are a really bad place to use an airtool. They strip easily if you're not careful.

Just my .02

-Hugh
'86 951

Greg86andahalf

Thos specs sound a little light to me. Tank size effects "sustained" PSI. I have a small one like that which is only used for blowing off stuff, filling tires and the like. My impact dies quick with it and is basicly useless. I was using it with an air chisel, but the dremel mini grinder w/cut-off wheel is quickly replacing it.

I have come to prefer hand tools especially where aluminum is involved. You can "feel" the bolts or nuts, and there is less chance of cross-threading or snapping things. Torque wrenches are a GOOD investment. I get the feeling that these cars are really made for hand tools and a gentle touch. I save air tools and sledge hammers for my GMC suburban.

I did the cv boots with hand tools. The 4foot long 3/4" torque wrench came in handy on the rear axle nut. (I know, I did not HAVE to pull the nut, but getting the axle out from the car where I could renew the boots, grease the joints and renew the caps seemed faster and easier that way).

my opinion anyway.

Matt

I agree, for shadetree mechanics like us I think money is better spent on a good selection of hand tools including, as Hugh said, torque wrenches. The torque wrenches are really valuable in helping to avoid the universal temptation to overtighten stuff.

In my mind, air tools come after you've put together a good set of hand tools and have used them a fair amount. Air tools are great, for disassembly in particular, but not a full substitute for the old-fashioned approach.

It's also very helpful to have on hand a spectacularly foul, rank and obscene vocabulary for those bolts that you just can't reach and snap rings that just won't come out.

Enjoy!

Matt

Zach C

While there are many torqued applications that require hand tools for assembly, nuematic tools make most jobs on these and any other car MUCH easier. Particularly, air tools are very useful for removing frozen nuts and bolts that have been torqued to 400 ft.lbs. Also, you can use your compressor to fill the tires, clean the garage, remove lug nuts, etc without needing room to ratchet a wrench. I consider nuematic tools to be the single most important purchase I have made for working on cars IMHO.

If you decide to go this route, and you plan on using an impact wrench of any usable strenth, you will need a tank capacity of 15 gallons minimum and a 3.5HP or stronger motor with at least 4cfm at 90 psi. Average impact wrenches run anywhere from 90 to 120 psi and use anywhere from 6 to 10 cfm. The above minimums will allow you use your wrench for relatively short duration, and you can expect the compressor to run almost constantly during the process. A larger tank simply lets you work longer without the compressor running, and you will not have to wait for pressure in the tank to build up before starting again.

The compressor you describe is probably sufficient to run an air nailer, fill the tires, or use light nuematic tools like a small grinder, but it will not keep up with the heavier constant air use of an impact wrench or an air-hammer for more than a few seconds. Most compressors of this size are designed for construction applications using nailers and other equipment that used only short bursts of air - not a constant stream.

Personally, I use a 25 gallon tank with a 5.5hp oil free motor and pump generating 6.5 cfm at 90 psi. This has proved sufficient for general home use with large powerful impact tools, but is by no means perfect. Going to a 60 gallon tank and a 10hp motor would be a huge improvement. So, basically you just need to decide what you need and what you can afford. Buying cheap air tools(as I learned the hard way) will just **** you off and result in repurchasing again in a few years. Good Luck - Just My 2 Cents.

my944

Rear shocks were the EASIEST job that I have done on my 944. Four bolts, a breaker bar, socket, jack and jack stands is all you need. Cake job.

951Tom

I'd recommend air tools to anyone thinking about it. I bought a cheap set of air tools at Sam's Club for $80. The home mechanic doesn't need a complete Snap-On set for $5K or whatever it costs. It came with a impact gun, air rachet, grinder, chisel, and bunch of other pieces and attachments. It's held up fine so far. Then I got a 30 gal. air compressor on sale at Sears for $250 that was in the paper. If you watch the paper ads or internet sales, you can find a good deal. It really makes working on the car less tiring and easier. Of course, only use them to loosen bolts.

Tabor

I purchased an oil-free 30gal 6.4cfm@90PSI, 8.6@45PSI 6hp compressor only after getting a bunch of hand tools.

This was the minimum I could get away with to run my "industrial" impact wrench. This was to get that stuborn rear axle nut off.

If you have the money, go for it. But I think you really want to get at least what I have.

marky522

i have a 60 or 70 gal, 6.5 horse, 220 amp compressor. I love it. I just need to break down and buy an impact with some *****.

Mark

Mike S

I have to agree with the last 3 or 4 posts on this one. I have a 60gal 6HP 220 volt air compressor that just rocks! Bought it from harbor freight, its a campbell hausfield if memory serves. For just over $450 its the best air compressor for the money. Having said that, you would NEVER, EVER, EVER, want to use an impact gun to tighten bolts. I suppose you could attach a torque stick which in theory limits the amount of torque on a bolt...but realistically I think tightening should be done with a wrench and finished with a torque wrench. Also, bigger is better when it comes to tank size. HP is important to, as well as cfm...but once you have it pumped up the tank size will determine how long you can run without the pump running. Also, keep in mind that air tools are very picky on the amount of oil and clean air they get...so make sure you have an in line oiler and air filter. A pressure regulator wouldn't hurt either. This all said and done, I would definitely put my money into good hand tools first(i can't see air tools helping you on the rear shocks) and then add a compressor at a later date. Like my dad said, its not the mechanic....its the tools.

RPG951S

Since we're at it... I'll add my datapoint.

I've got a small compressor 2.5HP / 6 Gallons.
With a decent air compressor, it gets off every nut I've come across so far, including wheel nuts, strut/shock nuts, exhaust nuts are various other thingies. Haven't tried in on any real biggee's thou (i.e. axle nut). It's increably cheap (paid < $150) and does exactly what I need it to do.
What I really like about compressors in general is the 'hammering' action. It's at least as important that the actual amount of torque it can apply.
I was in exactly the same position as you. I simply COULD NOT get the rear shock nuts off. I had a 4-ft breaker bar and everything, and I was bouncing up-and-down on it. I was sure I was going to break something
So I went out, and for $200 bucks (compressor/gun/hoses & connectors) I went home, and got the same nut off in 20 seconds!

My .02c

ribs

I got a 13 gallon/5 HP oilless air compressor, and a full set of ghetto (harbor freight) air tools. I have found the air tools to be useful for 2 things: impact wrench to remove lug nuts, saves a few minutes per wheel, and air ratchet to remove loooong bolts or bolts where lateral clearance (you can only get 1 click at a time with a socket wrench) is an issue. I think in my massive overhaul I am in the middle of right now, the air tools have maybe saved me 30 minutes out of 20 hours of work time...I am sure I will find more meaningful uses for them (like the air compressor to power my powdercoating machine...still being lazy with that one...gotta get some of my **** coated) but they seem like more trouble than they are worth for a lot of situations. By the time I run over to plug my compressor in, let it charge up to 120 psi, find the impact wrench/air ratchet, and start pulling bolts off, I could have done most of them by hand. I personally bought them because they make cool noises, and I am starting to think that is all they are good for...this is just my opinion, YMMV. Oh, the only thing I have found my impact wrench to be a life saver on was when I was trying to bolt the end of my axle to the hub on my celica...it would have been nearly impossible to do this with hand tools since the axle would just keep spinning...otherwise I would have needed someone else to clamp the axle down with a pair of vicegrips or something.

Steve Cooper

Oh oh. once you get yourself into a compressor and airtools, you'll probably need a decent MIG set-up, then as well, find justification for an Oxy/Fuel torch set, then a chop saw and for more precise work, a Plasma cutter, certainly a TIG welder for all the aluminum work, and finally a drill press, metal band saw and lathe to fab the tools you can't buy.

It's evil.

Steer clear and pay someone else to do the work

;-)

951Tom

While we're on the subject of air compressors, does anyone know if it's bad to keep the tank at full pressure, 120psi? Ribs, you said you have to wait for it to fill each time. I just leave mine full or at around 100psi. Is this bad?

Thanks & <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

jim968

I've had a compressor & air tools in my garage for about five years now. Frankly, I use them very little. It's nice to know that thery're there for the big jobs or really stubborn nuts, but most of the typical DIY stuff is quicker for an amateur like me with hand tools, by the time you plug in the compressor, uncoil / recoil the hose, etc.

When I just have to pull wheels, I use my trusty DeWalt _electric_ impact gun. It works fine, requires less hassle (cord vs. hose), makes less noise, etc... (still use the torque wrench putting lug nuts back on, tho').

For a pro wrench who's screwing and unscrewing all day long, no doubt it's a worthwhile investment; for an occasional DIY'er, I'd question it. I'd still do it myself, since I also have a couple of brad / tack nailers that run off compressed air. And air tools are cheap, so once you've justified the compressor to yourself, why not have 'em in your toolbox? But if it was just for occasional DIY wrenching, I'd spend the money elsewhere in my toolbox.

Just one opinion. As always, YMMV.

Jim, "Indecision is the key to flexibility." <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />