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Author Topic: Blowing out air cleaners-BIG NONO  (Read 5072 times)
TomC
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« on: November 18, 2009, 09:26:14 AM »

Every so often I real about someone blowing their air cleaner element out with an air gun.  This is never a suggested way to clean your air cleaner.  When blowing out the paper element, whether you see it or not, you're creating small holes in the paper allowing dirt to pass into the engine.  When you consider a big truck/bus air cleaner element is usually less than $100.00, just replace the element if their is a question about it being dirty.  Most NAPA auto parts stores will have them.  It is a whole lot cheaper then a $10-15,000 engine overhaul.  Good Luck, TomC
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Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
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« Reply #1 on: November 18, 2009, 11:16:39 AM »

Many years ago, I was the AGM of a transit system on the east coast.  We had about 50 fishbowls (half the fleet) with paper dry element filters.  The previous management directed maintenance to blow them out.  The result - we were overhauling 6V71's at 100,000-125,000 miles.  Way below standards.

From that experience, when having my cars serviced, I won't let them service the air filter - I change it myself.  I've seen Jiffy Lube type places shake the dust out of the filter, and put the filter back in.  Guess what - the dust they shook off the outside, lands on the inside -- thus inside my engine.

Pay me now, or pay me later.

Arthur
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Arthur Gaudet    Carrollton (Dallas area) Texas 
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robertglines1
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« Reply #2 on: November 18, 2009, 11:34:20 AM »

I learned something new today...I completly agree the way you explained it.. I worked with heavy equipment all my working life and all the mechanics blow out air cleaners.I won't be blowing out mine any more!thanks for the post..
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rv_safetyman
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« Reply #3 on: November 18, 2009, 12:15:44 PM »

Hi Tom.  I would like to explore this a bit further.

As an engineer and then a trainer of maintenance folks, I always had to deal with "textbook" vs "the real world".  In the textbook area there are really two types of textbooks.  Some are designed to sell the product, and some are based on real world experience.  That is what I would like to explore.

I assume you are basing your recommendation on either experience at the dealer, or an air cleaner bulletin.  Each has a quite different weight in my mind.  

In the ag industry, the NORM is to blow out the air filter almost every day.  In the dusty conditions, your could not begin to operate a combine if you had to replace the engine air filter every couple of days.  

I tried to do a bit of a search, but did not find a authoritative site.  I did find a military site that would suggest you can use air:  http://www.army.mil/-news/2009/09/30/28061-the-mechanics-corner--weekly-air-filter-maintenance-a-must/

Another source I found said you could use 30 PSI air.

I have always used an open 1/4 inch hose so that the air flow is not concentrated.

Don't mean to be contrary, just trying to learn.

Jim
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Jim Shepherd
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kyle4501
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« Reply #4 on: November 18, 2009, 12:52:56 PM »

How about a filter sock that keeps the big stuff out of the paper pleats?
You could service the sock without disturbing the filter seal to the engine.

Of course, adding this sock would increase the pressure drop across the filter, so you'd have to take that into consideration. . . .
If you're working with what you have, I'd think a standard filter minder would tell you when to clean the sock.

If you're buying a new filter assy - -it might be easy to oversize the unit to allow longer service intervals.


The only filter I have ever blown out is the one on my shop vac, but then again, my buses have the oil bath . . . .
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« Reply #5 on: November 18, 2009, 01:00:35 PM »

We had this same discussion some months back and it's all over the board. Some blow them out, others replace them. I replace mine , when it's needed. I don't even blow or shake it. I was told years ago to never blow them out, but that was in a different industry. Although the same principal. I have not read or heard of anything definitive in print to say what's best. I would really like to know what the real recommendation is from Detroit or other reputable business. I would think that blowing a paper element there is some risk of creating a hole you can't see. Of course the amount of pressure could make a difference, say 25 psi instead of 100 psi.
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« Reply #6 on: November 18, 2009, 01:53:12 PM »

Tom, has to be talking about highway use every Cat manual I have says to clean the pre filter and blow the air cleaner as needed with 30lbs of air each day when in dusty conditions.
You are not going to damage a Cat or any good air filter with air maybe the cheaper aftermarket stuff I paid 250 a pop for some air filters it would have broke me buying air filters according to Tom and FWIW I never lost a engine because of dirt and they never sold me on the lifetime K&N filters.Paul my Bomags had  350 hp 6v92  and manual said blow and that we did 3 or 4 times a day and replaced it every 100 hrs.
I am not afraid to clean a good air filter with 30 lbs of air
good luck
« Last Edit: November 18, 2009, 02:10:41 PM by luvrbus » Logged

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busnut104
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« Reply #7 on: November 18, 2009, 02:18:54 PM »

I have a 277B cat skidsteer with rubber tracks, in dusty cond. you have to shake and bump it out twice a day, I usually carry a spare that I clean with air at the shop. This is very poor design for cat, I have a bobcat that can run right beside it and you are lucky if you clean it once a week. Sucks the air in from the top and not the bottom like the cat. Any way both machines have a inter cleaner that stays pretty clean and would catch the fines.
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luvrbus
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« Reply #8 on: November 18, 2009, 03:54:05 PM »

Here you go guys I knew I read it somewhere in the DD manual  section 3.1 page 8 for a 92 series tells how to clean a filter with air also tell you how to wash one



good luck
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rv_safetyman
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« Reply #9 on: November 18, 2009, 04:12:33 PM »

One of the issues we have to deal with on our buses is that the air cleaner is generally in the read and the intake is about head high on many buses.  That is an idea collector for dust kicked up by our rear wheels.  A few years ago we had an Eagle rally in Quartzsite that was several miles off a paved highway.  I had to clean the air cleaner each day. 

As I say, I used an open 1/4 inch tube on the inside.  I used the bus air system, so the pressure started off at perhaps 100 PSI but quickly dropped, as I was not running the engine (obviously).

I have worried about cleaning the filter with air, as I know that you can damage them if you are not careful.  When I pulled my engine a couple of months ago, I carefully checked the inside of all of the inlet tubing and did not see any evidence of dust.  When we inspected the engine, there was a bunch of damage, but none that would have been caused by dust.

When I did my search, I found about equal recommendations on both sides of the fence.  It was interesting that several of the documents I found on the "don't use air" side were written by filter related businesses.

Jim
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Jim Shepherd
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Ed Hackenbruch
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« Reply #10 on: November 18, 2009, 05:07:04 PM »

Sounds like a good topic for mythbusters! Grin
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« Reply #11 on: November 18, 2009, 05:53:54 PM »


I bought my filter at International Truck place for $35 bucks.  It is hard enough to put in that I would not put a used one in or blow it out close to short time regularly.  Do need to fix my filter minder though Wink
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TomC
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« Reply #12 on: November 19, 2009, 12:10:11 AM »

If you're running an off road piece of powered equipment and you have to clean the element once or twice a day, the intake system is not designed right.  If you have a well designed pre-cleaner that evacuates most all the dust by cyclone action before it even enters the actual air cleaner, you should be able to go at least 100 hours on an air cleaner.  I saw a special on the biggest of Cat mining trucks, and they get 100 hours use out of their air cleaners.  I know at Freightliner for off road all wheel drives, we have a cyclone pre cleaner that actually sucks the dust out of the pre cleaner and by a hose connected to a venturi in the exhaust that pulls the extra dust and dirt up the exhaust stack.  Good Luck, TomC
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Tom & Donna Christman. '77 AMGeneral 10240B; 8V-71TATAIC V730.
Gary '79 5C
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« Reply #13 on: November 19, 2009, 12:27:11 AM »

I think there is another huge difference in the blowing out our current air filters VS, those manufactured 20,30,40 years ago. I believe the filters today are probably 1/2 as robust as back in the day. Our maintenance practices are radically different in industry due to labor costs & valued engineered products(made cheaper). I know the dealer supplied filters for my MB's are made off shore Pakistan & other locations...They are cheasy.

I would agree with Tom about blowing a hole in today's filters, but that might not have been a problem with 30lbs of air w/ older filters. As was indicated by Luvrbus on that.

Change 'em hot and often, like the oil.

Gary

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« Reply #14 on: November 19, 2009, 05:46:36 AM »

What about oil bath air cleaners?  what is the routine on those?

Brian
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