Author Topic: Filter indicator  (Read 2996 times)

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Offline Dwight Quertermous

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Filter indicator
« on: October 21, 2015, 07:54:54 AM »
Hi All - In a recent outing there was about 6 of us standing in the driveway behind my motor coach drinking a brew and someone looked at my filter indicator and asked me if I use that as a tool to tell me when to change my filter. I said "yea, kinda". Another chimed up and said they were junk and said just change it every 15K miles. The one standing there and smoking  cigar with a half glass of wine in the other hand said if they didn't work, then why did they (manufactures) put them on our coach. He said most all coaches have them. Another one said depends on conditions weather dusty or rainy. Any input from the community??
Best Regards
Dwight Quertermous
05 Fleetwood Excursion
CAT C-7 350 HP

Offline Brett Wolfe

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Re: Filter indicator
« Reply #1 on: October 21, 2015, 08:27:34 AM »
Dwight,

Don't know about the cigar, but we can stand behind the coach with a glass of wine and discuss this at the next DRVC Rally the end of February: http://www.dieselrvclub.org/event-2011388. Will also discuss it in the seminars at the Rally.

The AIR FILTER MINDER is ONE of the tools to help determine when to change the air filter.

Let's walk through the whole thing:

The first time you stop after replacing the air filter AND doing at least 30 seconds at WOT at higher RPM's, record the air filter minder reading.  Hopefully it will be near the bottom of the scale.  Remember it reads total system restriction, so too small an intake on the side of the coach, too long a flex hose between side of coach and air filter, etc all add to restriction. That will be your benchmark to allow you to monitor additional restriction caused by dirt on the filter.

As the filter filters out dirt, the air filter minder reading will increase-- that is its job.  As I am sure everyone is aware, the rate of increase in restriction is highly dependent on how much dirt is in the air.  Driving for 30 miles in a sand storm across southern NM or AZ will create more restriction than 10,000 miles of non-dusty conditions.

Not all intake systems are created equal-- some don't do a very good job of keeping water out of the filter if you drive in rain.  Water on the filter element makes them degrade in a hurry.  Also, the glue that holds the filter together as well as the paper element degrade with time, even if kept dry.

Also, "Bubba" has been known to remove a filter and bang it on the ground to get out some of the dirt.  That may (more likely) or may not break some of the pleats allowing direct entrance of dirt to the engine and a lower air filter minder reading.

Twice in my career of doing mechanical inspections on coaches have found that animals (suspect mice) have set up housekeeping in the air filter.  Guess the paper makes a nice soft nest.  Were that engine driven more than a few miles, it would be dusted/ruined.



All this is leading to a scary conclusion-- a low air filter minder reading does NOT necessarily mean that the filter is in good shape.  It could also mean that the filter has failed, as holes in the filter will always return low air filter minder readings.

SO, consider replacing the filter either because of high readings (too much restriction) OR when the filter is 3 years old (before the paper and glue degrade to a point that the filter fails) or if you see signs that would suggest that the filter has been compromised..

Also, once a year, test the air filter minder.  Remove the vacuum line and suck on it.  That should peg the meter and it should hold that reading until you push the button on the bottom to reset it.

Brett

Offline ziggyh

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Re: Filter indicator
« Reply #2 on: October 21, 2015, 11:06:48 AM »
I have read technical articles from some manufactures that stated it takes 1 cup of dust to wear out an engine whether it is ingested in a day or years.

Brett, the three year service interval has had me wondering about buying old stock.  I do change my filter at a max of 3 years for piece of mind since I don't think there's  enough room for the paper to pass through the turbo. One filter manufacture indicated that the three year deterioration only starts when you start to use the filter and sitting on the shelf doesn't count??

Note on filter minders, they are different for gas and diesel when replacing need the correct one, will post the spec for both.
ZiggyH

2007 Revolution LE
C9

Offline Brett Wolfe

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Re: Filter indicator
« Reply #3 on: October 21, 2015, 12:15:06 PM »
Ziggy,

I make it a point to buy filters from places with a lot of turnover.  I would think paper and glue CAN deteriorate even on a shelf.  I know if I gently put a pile of cardboard or newspaper in a dark, dry closet, in 3 years it is certainly not as strong.

I have no experience with air filter minders of gasoline engines, but would assume that as long as it is placed "upstream" of the throttle it would work the same.

Offline ziggyh

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Re: Filter indicator
« Reply #4 on: October 22, 2015, 07:59:49 AM »
Brett, I have no problem agreeing that the three year deterioration applies regardless of whether the filter is on the shelf or installed, At one point I thought that the induction system fumes/gases when the engine is off may account for some makers saying the service life starts after it is installed. But that was my thoughts.

Better safe than sorry, filters are cheaper than turbo's

The spec that I have found for filter minders is: Gas 15-20 inch of water Column,  Diesel 20-30 inch of water Column for when the minder indicates replace.
Gas filter minders are upstream of the throttle plates and do work the same
ZiggyH

2007 Revolution LE
C9

Offline Dwight Quertermous

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Re: Filter indicator
« Reply #5 on: October 24, 2015, 09:57:51 AM »
Interesting... So not only does the indicator tell a story, but if the element inside the filter is degrading, the indicator will not let you know the filter is failing. Sounds like a once a year visual inspection is warranted. Thanks guys, valuable information here.  :-\
Best Regards
Dwight Quertermous
05 Fleetwood Excursion
CAT C-7 350 HP

Offline dcbopp

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Re: Filter indicator
« Reply #6 on: July 08, 2017, 03:37:18 PM »
Brett or anybody out there in Beaver/diesel  land-----  I just acquired a low mileage (14000) 2003 Beaver Marquis. The filter indicator stays pegged all the time. I reset it but soon as you give it full throttle, it's pegged again. I tested it and all seems normal. I question the installation of this air filter because it's mounted in such a way that the incoming air goes into the end of the filter and comes out of the side of the metal housing and headed to the turbo. In other words, the incoming air goes into the ID of the filter.  I've never seen an air filter mounted this way. Dirty side should be to the OD. I've made several calls to Rv dealers, but nobody knows. Installed a new AF just in case it was plugged somehow, but made no difference.  Has anyone ever heard of this problem?

David Bopp
2003 Beaver Marquis with C12   505
Honda pilot toad w/ Vase brake system

Offline Brett Wolfe

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Re: Filter indicator
« Reply #7 on: July 09, 2017, 07:38:36 AM »
David,

Both "dirty air in outside, clean out center" and "dirty air in center, clean air out outside" are well recognized as good in the industry.

BUT, most filters are designed for EITHER one or the other (yes, a few are bi-directional).

So, first step is to pull the filter, check the number and verify that it is correct for DIRECTION OF AIR FLOW, not just shape and size of element.

Also, the air filter minder reads total restriction, not just filter.  Recently, had a guy pull a birds nest out of the air intake-- same pegged air filter minder.

So,  check the whole intake side of the system from side of coach to turbo.

Brett

Offline dcbopp

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Re: Filter indicator
« Reply #8 on: July 09, 2017, 05:43:05 PM »
Thanks Brett,  I already did that cause I'm a mechanic by hobby.  All is clean throughout. It's an LAF1848 Luberfiner with 7" in and 7" out or visa versa.  Beaver people from that era seem to be all gone. There was one guy that supposely would know, but can't reach him yet.  I had hoped somebody here on the forum had run into this situation. I'm tempted to remove the AF and run a power test and see if guage moves.  Lots of dirt back there though.   

David
2003 Beaver Marquis with C12   505
Honda pilot toad w/ Vase brake system

Offline dcbopp

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Re: Filter indicator
« Reply #9 on: July 09, 2017, 05:46:01 PM »
One more thing Brett,  There are no markings showing inlet or outlet.    David
2003 Beaver Marquis with C12   505
Honda pilot toad w/ Vase brake system

Offline Brett Wolfe

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Re: Filter indicator
« Reply #10 on: July 10, 2017, 05:44:18 AM »
Contact Luberfiner and ask if that is the proper element for your direction of air flow.