Skip to main content ↑ ↓
Topic: Cummins Air Filter Restriction Gauge Question (Read 1052 times) previous topic - next topic

Cummins Air Filter Restriction Gauge Question

Motivated by Roger's dusted air filter experience, I ordered a new Fleetguard AF1838 for our 99' U270 with the 350hp 8.3 ISC.
I got it from Simply Filters for $87.31 w/free shipping (the one I got from Filterbarn was only $59 2  years ago, but they were out of stock. In the process of changing it out, I ran into a possible issue with the restriction gauge. If I put a vacuum on the hose which goes up to the restriction gauge from the air filter cover, and then while leaving the vacuum hose disconnected at air cleaner end, press the button on the restriction gauge to release the hold on it, the gauge indicator goes right down in less than second. If the vacuum hose is reconnected up to the air cleaner cover after I max out the tell tale yellow float indicator, I have to hold down the release button on the restriction gauge for several seconds before it clears. Does that brass elbow have some sort of small diameter port on it, or some other kind restriction built into it? It appears to be pressed into the lid so I am reluctant to try and unscrew it to take a closer look. If I put a tube on it and blow through it, there is a lot of resistance as if I was trying to blow air through a ball inflating needle. :o
Don
The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Cummins Air Filter Restriction Gauge Question

Reply #1 –
Don, check the large end of the filter,there needs to be a small hole in the center for the filter minder to work.
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Cummins Air Filter Restriction Gauge Question

Reply #2 –
Actually, Bill, the small end of the filter with the small hole (1/8") goes towards the rear of the coach and the big end with the big hole goes to the front. As the filter starts to get dirty the pressure inside the filter cone is reduced (the engine has to suck harder) and the restriction guage reads higher. A new filter and the guage reads low.  About middle is normal.  If it is in the middle and suddenly goes to zero then you have had an air filter failure, no restriction.

I hope that is right because that is how Cummins put in my new filter which by the way (and my rebuilt engine) is working very nicely.  22 hrs on the clock so far. Starts instantly, they cleaned and greased all of the start battery cables and connections to the starter.  Turns over very quickly on my Yellow Tops.

Roger
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Cummins Air Filter Restriction Gauge Question

Reply #3 –
Quote from: Roger and Susan in Home2 –
Actually, Bill, the small end of the filter with the small hole (1/8") goes towards the rear of the coach and the big end with the big hole goes to the front. As the filter starts to get dirty the pressure inside the filter cone is reduced (the engine has to suck harder) and the restriction guage reads higher. A new filter and the guage reads low.  About middle is normal.  If it is in the middle and suddenly goes to zero then you have had an air filter failure, no restriction.


Roger

Roger,

Slight correction:  The air filter minder records AND RETAINS the highest restriction.  So, a filter element that breaks down (and therefore has less restriction) will NOT read a lower restriction unless you reset the air filter minder (button on the bottom).  It will then record and retain the highest restriction from that point forward.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Cummins Air Filter Restriction Gauge Question

Reply #4 –
The filter does have a small hole on the small end which faces the rear of the coach (big end of filter with the large opening towards the turbo, only way it will fit!) to read the engine side vacuum and the gauge does hold the highest vacuum it reads. It is the release of the vacuum that I am talking about. With the vacuum line hooked up to the air filter lid, regardless of whether or not the lid is sealed to the intake can as in normal use or the lid is detached from the can and therefore exposed atmospheric pressure, the gauge returns to zero very slowly. When the hose is detached from the lid, the gauge returns to zero very quickly. My question then, is the slow float down return to zero on the gauge when pressing then release button normal behavior or should it quickly return to zero when pressing the release button, as it does when the vacuum line is open to the atmosphere? In other words, is the restriction I am seeing at the vacuum line nipple on the air filter lid abnormal? :headwall:
Thanks, Don
The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Cummins Air Filter Restriction Gauge Question

Reply #5 –
Brett is correct.  I misinterpreted whatbI was looking at.  Sure would be nice to have something like a tire pressure monitor that sounds an alarm if the restriction is too high or too low. 

Don's question? I do not know. Roger
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Cummins Air Filter Restriction Gauge Question

Reply #6 –
Don,

From Filter Minder

The Filter Minder® should be reset whenever the service indicator is checked to determine air filter restriction or when a new air filter is installed. Push the reset button at the end of the service indicator, and the position indicator will return to zero.

If the air filter has not been replaced, the position indicator will return to the same reading when the vehicle is driven under normal driving conditions.

High humidity and rainy conditions can make air filter restriction increase more than dry air conditions. The Filter Minder ® reading may show a slightly lower or higher reading after being reset and the vehicle operated depending on atmospheric conditions.

Filter Minder® Frequently Asked Questions

Maybe some answers here.

Roger
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Cummins Air Filter Restriction Gauge Question

Reply #7 –
Don, to try to answer your question. Not on ours but others that I have checked the gauge and pressed the release the indicator has dropped immediatly. Mine has never moved (but it does work thru testing) just that the filter never gets a work out anymore!!
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Cummins Air Filter Restriction Gauge Question

Reply #8 –
My bad about the small hole.
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094

Re: Cummins Air Filter Restriction Gauge Question

Reply #9 –
Don,
I think the fitting on the filter housing contains a 40 micron filter as a safety device. Those fittings are available with or without the filter. See attachments.
Interesting thread; I would like to know what you find.
Dick
Dick, '03 U320 40' Tag, 2 slides, Coach #6075
Full Timers
2009 Honda CR-V

Re: Cummins Air Filter Restriction Gauge Question

Reply #10 –
Dick,
The 40 micron filter is in the nipple which is screwed into the brass elbow on the air can lid, which appears to be pressed in. The brass nipple with the filter is not the source of the restriction as the gauge returns to zero quickly when that is connected to the vacuum tube but unscrewed from the brass elbow. Plus, I can fairly easily blow through it. When I took the nipple off of the elbow and saw the filter, I thought I had found the restriction and was quite surprised that that wasn't the case.
Don
Quote from: Dick S –
Don,
I think the fitting on the filter housing contains a 40 micron filter as a safety device. Those fittings are available with or without the filter. See attachments.
Interesting thread; I would like to know what you find.
Dick
The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson

Re: Cummins Air Filter Restriction Gauge Question

Reply #11 –
Shucks, I thought that might be the answer too.
So it must be something in the fitting between the filter and the housing for the air filter? What is left?
Dick
Dick, '03 U320 40' Tag, 2 slides, Coach #6075
Full Timers
2009 Honda CR-V

Re: Cummins Air Filter Restriction Gauge Question

Reply #12 –
I forget where, but 2 weeks ago I had my filter housing apart and remember saying "gee, that looks like a pretty small hole". I think it was in the little brass elbow thing. So that probably answers your question. I blew through it to make sure it was clear.
1998 U270 34'
 

Re: Cummins Air Filter Restriction Gauge Question

Reply #13 –
Only the elbow which is pressed (I think) into the air filter can lid. It may have a tiny venturi port to deliberately restrict the air flow, and that is what I am trying to determine. If it is a blockage of some sort, then I may just live with it because I don't want to buy a new can lid for it. Unless that elbow unscrews... if so, then I could replace it. I would like to know that I can rely on the filter minder.
Don
Quote from: Dick S –
Shucks, I thought that might be the answer too.
So it must be something in the fitting between the filter and the housing for the air filter? What is left?
Dick
The selected media item is not currently available.
Don & Tys
1999 U270 3602 WTFE #5402
Xtreme Stage 1 w/Headlight, Step Conversion, etc.
2009 Honda Fit Sport with Navi
Freedom is NOT "just another word for nothing left to lose"... with apologies to Kris Kristofferson