impact wrenches and air compressors

how do the spec-s of an air impact wrench relate to the air
compressor?
i need to loosen a crankshaft pulley bolt that is torqued at 134 ft-
lb. on a 1998 honda civic LX. i have a sears craftsman 1.5hp 4-
gallon @90psi air compressor. i don't yet
have an air impact wrench. what should i look for in terms of psi
when i go to buy one, such that i can use that air compressor to drive
the impact wrench to loosen the bolt? tia.

wrote:
> how do the spec-s of an air impact wrench relate to the air
> compressor?
> i need to loosen a crankshaft pulley bolt that is torqued at 134 ft-
> lb. on a 1998 honda civic LX. i have a sears craftsman 1.5hp 4-
> gallon @90psi air compressor. i don't yet
> have an air impact wrench. what should i look for in terms of psi
> when i go to buy one, such that i can use that air compressor to drive
> the impact wrench to loosen the bolt? tia.

I have a 5 gallon tank and 3 hp motor and can get about 5 seconds of
good impacting with a 1/2" drive Campbell Hausfeld impact gun.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

wrote:
> how do the spec-s of an air impact wrench relate to the air
> compressor?
> i need to loosen a crankshaft pulley bolt that is torqued at 134 ft-
> lb. on a 1998 honda civic LX. i have a sears craftsman 1.5hp 4-
> gallon @90psi air compressor. i don't yet
> have an air impact wrench. what should i look for in terms of psi
> when i go to buy one, such that i can use that air compressor to drive
> the impact wrench to loosen the bolt? tia.

I removed the crankshaft pulley bolt on my Mom's Civic. I tried three
different 1/2" drive impact wrenches (one of them was a professional
quality Ingersoll-Rand impact wrench borrowed from my ex-auto-mechanic
neighbor) and none of them budged it after many minutes of trying.
A 3/4" drive impact wrench from the rental store got it loose in a
couple of seconds.

As the other poster said, cheap impact wrenches will suck up a lot of
air, they're OK for most home jobs like undoing wheel lug nuts but
for stuff that's really stuck you will like having a higher quality
more expensive tool. And for really stuck stuff nothing will beat a
FOAD 3/4" impact.

wrote:
> how do the spec-s of an air impact wrench relate to the air
> compressor?
> i need to loosen a crankshaft pulley bolt that is torqued at 134 ft-
> lb. on a 1998 honda civic LX. i have a sears craftsman 1.5hp 4-
> gallon @90psi air compressor. i don't yet
> have an air impact wrench. what should i look for in terms of psi
> when i go to buy one, such that i can use that air compressor to drive
> the impact wrench to loosen the bolt? tia.

Crankshaft pulley bolts can be difficult to loosen sometimes.
90 psi may not do it. 110 psi would be much better.
For a impact, just get a good brand name and it should be ok.

On Thu, 2 Oct 2008 04:57:05 -0700 (PDT), wrote:

>
>how do the spec-s of an air impact wrench relate to the air
>compressor?
>i need to loosen a crankshaft pulley bolt that is torqued at 134 ft-
>lb. on a 1998 honda civic LX. i have a sears craftsman 1.5hp 4-
>gallon @90psi air compressor. i don't yet
>have an air impact wrench. what should i look for in terms of psi
>when i go to buy one, such that i can use that air compressor to drive
>the impact wrench to loosen the bolt? tia.

They stretch the truth a bit I think.. those bolts are in there with a
lot more than an 134fl-lbs of torque. You are going to need a 3/4
drive to get it off most likely.

You may be able to find a local shop that will break it loose for you
and snug it back up if you slip them a $20. That's usually what I end
up doing as they have the high powered stuff and my dinky home owner
stuff just can't break them loose.

Steve B.

I have loosened up and removed one or two crankshaft pulleys before with
a 3/4 '' breaker bar and a big hammer or a 3/4 '' breaker bar and a
cheater pipe.No impact wrenches needed.That was on vehicles with manual
shift transmissions.
Cheater pipes Rule!
cuhulin

Steve B. > wrote in news:spfae41o4bmqho02u9lg6hvhjjul7vfprj@
4ax.com:

> On Thu, 2 Oct 2008 04:57:05 -0700 (PDT), wrote:
>
>>
>>how do the spec-s of an air impact wrench relate to the air
>>compressor?
>>i need to loosen a crankshaft pulley bolt that is torqued at 134 ft-
>>lb. on a 1998 honda civic LX. i have a sears craftsman 1.5hp 4-
>>gallon @90psi air compressor. i don't yet
>>have an air impact wrench. what should i look for in terms of psi
>>when i go to buy one, such that i can use that air compressor to drive
>>the impact wrench to loosen the bolt? tia.
>
> They stretch the truth a bit I think.. those bolts are in there with a
> lot more than an 134fl-lbs of torque.



No they are not.



> You are going to need a 3/4
> drive to get it off most likely.



No. A 1/2" drive DeWalt DW-293 325 ft/lb electric impact wrench takes it
off easily.



--
Tegger

On Fri, 3 Oct 2008 02:12:46 +0000 (UTC), Tegger >
wrote:

>> They stretch the truth a bit I think.. those bolts are in there with a
>> lot more than an 134fl-lbs of torque.
>
>
>
>No they are not.
>
>
Sure seems like they are. I've tightened back to spec and it's no
where near what it took to get the damn thing loose.

>
>> You are going to need a 3/4
>> drive to get it off most likely.
>
>
>
>No. A 1/2" drive DeWalt DW-293 325 ft/lb electric impact wrench takes it
>off easily.

I think I'll save the $178 and just pay the guy $20 to bust it loose
for me. I never met an electric impact wrench I was impressed with.

Steve B. > wrote in news:um5be4tr6b8mad1r3mi6rnk7sa734ja3nv@
4ax.com:

> On Fri, 3 Oct 2008 02:12:46 +0000 (UTC), Tegger >
> wrote:
>
>>> They stretch the truth a bit I think.. those bolts are in there with a
>>> lot more than an 134fl-lbs of torque.
>>
>>
>>
>>No they are not.
>>
>>
> Sure seems like they are. I've tightened back to spec and it's no
> where near what it took to get the damn thing loose.



You're absolutely right. And here's a Honda document explaining why:
http://www.tegger.com/hondafaq/cranktool/A930200.pdf



>
>>
>>> You are going to need a 3/4
>>> drive to get it off most likely.
>>
>>
>>
>>No. A 1/2" drive DeWalt DW-293 325 ft/lb electric impact wrench takes it
>>off easily.
>
> I think I'll save the $178 and just pay the guy $20 to bust it loose
> for me. I never met an electric impact wrench I was impressed with.



I'm certainly impressed with mine. For me it's ideal because there's no way
I can have a compressor where I live. And it's available at any time,
without having to drive to a garage.

Its only drawbacks are size (a foot long) and weight (five pounds). I can
use it on any bolt where I have room, which means such nasties as crank
bolts and (corroded) suspension bolts. Its bulk does make it useless in
tight quarters. And it's never failed to get any bolt loose that I've ever
been able to directly attack.


--
Tegger

wrote:
> how do the spec-s of an air impact wrench relate to the air
> compressor?
> i need to loosen a crankshaft pulley bolt that is torqued at 134 ft-
> lb. on a 1998 honda civic LX. i have a sears craftsman 1.5hp 4-
> gallon @90psi air compressor. i don't yet
> have an air impact wrench. what should i look for in terms of psi
> when i go to buy one, such that i can use that air compressor to drive
> the impact wrench to loosen the bolt? tia.


Pressure matters less than volume. Most impact wrenches (most air tools
PERIOD) are designed to work fine as long as you can give them 80 PSI.

Volume is another story- your compressor needs to be able to keep the
tank pressurized as you use the tool. Impact wrenches aren't very
demanding because you use them in short bursts, and even a very small
compressor can re-fill the tank between bursts. Just don't try to make
like a NACAR tire changer and whip 10 lugs on and off in less than 13
seconds...

The most demanding air tool in my kit is the smallest one- the cut-off
wheel. Since it spins at high speed and is constant use, it keeps my
5-horse compressor running about 80% of the time. On the other hand, I
can change 2 tires with the impact wrench just with a portable 11-gallon
air tank filled to 120PSI and no compressor at all.