fuel vacuum problem?

[maxtotow]

hey guys
I just checked out my new fuel vacuum gauge that i bought from Kennedy Diesel. I wonder if i may have a problem lurking?
I have about 6" of vacuum at idle. I have the new dealer installed filter about 3500 miles ago and also have pre-OEM Cat 1R-0749 filter that i changed about 2500 miles ago. I also have the Transfer Flow 45 gallon fuel tank. I have had the tank and extra filter about 2 years and 25000 miles. I have never been aware of any problem with the fuel or engine. It runs great. I have about 60000 miles now. It is a 02 LB7.
The service manual says 5" of vacuum throughout the RPM range.
I noticed the vacuum stays at about 3" even after i shut the truck off and keeps that until I remove the gauge and push the little plunger in on bottom.
Should i just use the vacuum I get as a baseline and look for any further increase? or is this way out of line and indicating a problem?

thanks for any advice

[Kennedy]

Start with a fresh set of filters and a check with varying levels (starting at full) of fuel.

One of the key desing criteria with my Mega kit was to use a filter large enough to handle a lot of dirt and pose virtually no restriction.

P.S. I've had OEfilters start to load at very low miles. Last one needed an emergency change at 0 f in an IA rest area. It had 8k on it and pulled the gauge around to 5 psi on the pressure side. That's WITH my lift pumps putting around 8psi on the inlet of this filter...

[tanker]

I just checked mine with new filter installed. I read 3" vacuum with the new filter. The old filter read 4-1/4" vacuum, so I guess thats my base line, 3". smile.gif

[maxtotow]

i think i will put fresh filters on and check again. I have two or three of the orginal style OEM filters on hand. I don't see why i could not use them up first. I have the pre-OEM setup with the CAT filter.
When i took the truck in for the free new style filter I asked the service writer if I could still use the old style filter I have. He said no problem.

[maxtotow]

Changed to new "old" style filter. vacuum now about 3.5". The filter did not look that dirty. maybe just having all that extra filter paper causes more restriction.

[Kennedy]

Originally posted by maxtotow:
Changed to new "old" style filter. vacuum now about 3.5". The filter did not look that dirty. maybe just having all that extra filter paper causes more restriction. Not when new. The filter restriction new is quite close between the two. I'd look at changing your pre filter AND question it's quality if it let the OE fill up so fast.