DennisT

Slowly checking over more and more things on my '97 2500 CTD I got a couple months ago. Looking at the glove box, "manual," and the cute little, "Air Filter Minder," sitting on the under-hood air cleaner, the tech writer for the manual could have done a better job. I'm sure once a fellow sees this thing work it will be clearly understood. I haven't yet.

First, the book says one can push the button on top and reset it, and if the filter is dirty it will quickly return to the, "replace filter," position. (Book is unclear if that position is with the disk up or down) Well, pushing the, "button," on mine does nothing. The manual also does not really say if the Minder's little disk is showing good sitting high, or low. Mine sits low at the 25 mark. If that means I have a fresh filter (which I think I do-book also says don't look), then that's why the thing doesn't reset. Nothing to reset to.

Help me here.

With the disk sitting at 25, is that good or bad? Or is this Minder even worth fooling with?

Thanks,
Dennis

SPLnut

if the filters clogged or minder is weak it will suck the yellow disk down into the center of the sight glass

DennisT

Thanks. So mine is showing what you say: clogged filter or weak Minder. (My disk is sitting low, at, "25.") First I wonder how long these, "Minders," last? Second I notice the glove box manual says don't look at the filter which sounds typical of the, "take everything to your dealer," talk.

Do the filters look dirty when they clog or not? I'm accustomed to looking at conventional engine air filters, are these any different?

I guess I'll change the filter and see what the Minder shows then...........

Dennis

SPLnut

is the yellow disk down at the 25 mark or you just seeing the red line at the 25 mark?

SPLnut

if the yellow disk is at 25 and you push the button on top the minder it should come up to the top if nothing happens take off the top and make sure its not already up

DennisT

I'm seeing a red line, or ring at the 25 mark. I also see a little conical coil spring in the empty space above the red line. I'm not sure where the disk is now that I think about it. I was thinking it was at the 25 mark, but you guys might recall where this coil spring is.....above or below the disk?

I guess the top might unscrew...haven't tried that either. Gotta be simple but I didn't want to mess with it without having an idea what to expect first. "Messing," with things on older machinery didn't hurt much....now we have so much plastic and junk assembly I never trust things are serviceable.

Dennis

SPLnut

the red line isn't the disc...the disc is yellow and will be up high in the minder if your just seeing the spring...the box top is held down by 4 clips on 3 out of 4 sides and the fourth is plastic legs on the box the top slides off those...Pop her open and check that filter (make sure ones in it)

gmctd

The blurb in the owner's manual means don't try to judge filter condition by appearance only - if the yellow disk in the differential pressure sensor, or 'filter-minder', drops to 14 at full throttle, the air filter is dirty, no matter how it looks - if the disk drops to 14 at normal throttle use, the air filter is really dirty, and you should be blowing smoky haze everywhere you go - if it drops to 25, you're an environmental hazard, and can be seen from space.

The differential pressure sensor is calibrated for vacuum in inches of water, or "H2O - so, that scale is 14" to 25"H2O vacuum - gassers (patooie!) run ~25"HG vac at idle because of the throttle plate - Diesels don' need no steenkin' vacuum - change your air filter if the 'minder shows yellow 14"H2O vacuum at hiway speeds, or incident of rapid acceleration.

Hope this is helpful to ya.

My bad - sbt - corrected - H2O for Diesel filters, H2O for gasser filters, HG for gassers in intake manifold

27"H2O = 2"HG = 1psi

LJTyre

The spring pushes the disk to the top of the bulb, if you see the spring and no disk, you're good. As the motor has to suck harder (dirty filter), the disk is pulled down against the spring, showing in the bulb. Then you push the button and the spring pushes the disk back out of sight.
It can be a little confusing before you see it work, but once your filter clogs up and you see it in action, you'll never doubt it again.

infidel

Trust the filter minder, it's such a simple device that it rarely fails unless it's visibly broken.
More than you ever wanted to know about a filter minder here>
www.filterminder.com

DennisT

Thanks, Inf. Interesting web site for Minders. I did notice them talking about the, "yellow," button on top. Mine has a black rubber'y top, but nothing at all on the top that is yellow.

From their web site, I can see what the disk actually looks like.

I checked my filter, which appears new. And now that I know the actual disk is sitting at the top of the Minder, (can't really even see it well), I think everything is as it should be.

Thanks again everyone,
Dennis

bubbalu21

I am totally new to the whole CTD thing so i was wondering if anyone had a picture of the "filter minder" they could post on here.

RenegadeT

geez, there might be one on the website shown 2 posts up.

12valve

even totally new stock air filters will pull the yellow disk down, if you have more then stock power!
mine pulls the yellow disk down halfways with a clean K&N

ScottN

Filter minders are great, it is too bad the one on my CTD is busted.

I drove two semis regularly last summer, one had a vacuum guage between teh air filter and turbo, the other had a dash mounted filter minder. It is pretty cool to see how the pressure difference caused by the restriction of the air filter changes with load and use, and would be great when looking for the best intake, etc.