secondary fuel filter buzz/squeal revisited

Fredsvt · April 4, 2017

Good evening,

Today, I had a 2013 F350, stock trcuk, 200k on the clock in for brakes, and some other minor issues, brakes, door ajar switches, and a general look over. I did see the one of secondary filter's quick connects partially unhooked.

I had my boss call the owner and ask him when the last fuel filter set change was, he was unsure, so he said change them.

The primary filter was quite disgusting, but no issues changing both filters, and ensuring the secondary filter's quick connects were on and secure.

I performed 7 koeo cycles, until the lift pump cycled. The truck started no issues and test drove it for the brake work I performed.

Upon returning, I heard the noise, it was much louder than I had heard on videos I've seen.

I pulled the truck back in to re bleed the brakes and quickly shut off the truck and went koeo. The thing was squealing so loud, it was almost deafening. After the pump cycled off I did what I needed to. Upon restart and test drive, no more noise. The filters in came in with were quiet.

Can these filters trap air? I did beat on the truck as I did on my first ride, after searching here and seeing a mention of a filter that would only start to squeal over 3000 rpm.

I have limited experience with any oddities with the 6.7. Most of our customers have zero issues with them.

RyanG · April 5, 2017

I have had a couple make noise after a filter change and yes I do think its air trapped in the filter housing or its pulling air from leaking quick connects. I've had luck taking the lines back off and pushing them back on or changing the filter out with another.

Bruce Amacker · April 5, 2017

Double check the o-ring on the primary FF- did you grease it on install? If it rolled it will suck air. Ditto for the water drain o-ring. Other than that the most likely is a cracked plastic sender fitting on top of the tank. A suction leak at either place will cause FF2 buzzing. FF2 is under pressure, FF1 is under vacuum.

Good Luck!

Fredsvt · April 5, 2017

On the primary filter I put a small amount of silicone brake grease on the cup as coming off was extremely difficult.

The old filters weren't noisy, and the truck's owner didn't say anything about odd noises.

After I had shut the truck down for about 10-15 minutes completing second brake bleed, it didn't squeal on start.

On test drive, running it as hard as before, no more noise. Hopefully it stays quiet.

8WA Sman · April 6, 2017

FF2 is under pressure, FF1 is under vacuum.

I never thought about like that.That's a great insight...I'll go back to :popcorn:

Keith Browning · April 6, 2017

Grease is not the best lubricant for fuel filter o-rings - its too thick AND every time I have trouble getting a cap off because the o-ring was resisting it showed signs of grease. Use clean engine oil. I use a bottle of 75/140 synthetic axle lube on my bench with the squirt top because it seems to be very slick. Oils seem to allow the o-ring to roll back into its original shape easier. I liberally lube the o-ring before pitting or on the cap or the housing and then the caps sealing surface just before installing. NEVER have an issue.

Bruce Amacker · April 6, 2017

Grease is not the best lubricant for fuel filter o-rings - its too thick AND every time I have trouble getting a cap off because the o-ring was resisting it showed signs of grease. Use clean engine oil. I use a bottle of 75/140 synthetic axle lube on my bench with the squirt top because it seems to be very slick. Oils seem to allow the o-ring to roll back into its original shape easier. I liberally lube the o-ring before pitting or on the cap or the housing and then the caps sealing surface just before installing. NEVER have an issue.

Thanks, Keith, I'll take that under advisement.

As for the FFs being vacuum/pressure, that goes back to 6.4 and 6.0 also. I've seen plenty of issues with earlier trucks caused by rolling the FF1 o-ring. If Keef says oil is the way to go, I'll suggest oil from now on.

:grin:

forddieseldoctor · April 6, 2017

What about trans assembly lube or vaseline?

Chad_Kelsoe · April 6, 2017

I've used trans assembly lube for the last few years and haven't had any issues that I know of. I've had to take plenty of filters out where the person before did not lube the o-ring and it was tight coming off.

8WA Sman · April 6, 2017

I use silicone dielectric grease. I also use the on the outside of FF2, I have yet to have one get stuck in the bracket.

Info from Parker lubricantusage.pdf

Parker-O-Lube.pdf

parker_o-lube.pdf

lmorris · April 6, 2017

I just use diesel fuel.

mrbudge · April 6, 2017

I was told once not to use silicone based lubricants on fuel systems because it will not dissolve in fuel, and if used on a gas engine it could potentially contaminate oxygen sensors. Have not verified either claim, but I don't want to find out.

cbriggs · April 7, 2017

I use wurth HHS 2000. It is a spray grease that goes on super runny and then within seconds turns grease like, but way more slippery. It also works good for lubing the weather pack seal when reconnecting electrical connectors.

Jeff_E · April 15, 2017

I use petroleum jelly liberally and never had a problem.

My high school shop teacher, Mr. Frye always said: "Nothin goes together dry or dirty, if you don't learn it in my class you'll learn it in health."

I wonder what he meant by that :chinrub2:

forddieseldoctor · April 15, 2017

I was told once not to use silicone based lubricants on fuel systems because it will not dissolve in fuel, and if used on a gas engine it could potentially contaminate oxygen sensors. Have not verified either claim, but I don't want to find out.

There is actually a warning in the workshop manual about silicone spray contaminating the nox sensors.