Having trouble removing secondary fuel filters

RiverGalsMan

RiverGalsMan

Member
Nov 3, 2006
327
Shady Side, Maryland
Boat Info
2007 44 DB
Engines
Cummins QSC 500
I was winterizing the boat yesterday and I couldn't get the spin-on secondary fuel filters un-screwed. I have a strap wrench and the filters wouldn't budge. The wrench wasn't slipping, either. I just gave up as I was expending way to much effort trying to get that done. After thinking about it today, I've got two theories on why I'm having this problem:

1) the spin on fuel filters are righty loosy, lefty tighty. If this is the case they're on pretty damned tight, right now.

2) because the QSC's are High Pressure, Common Rail (HPCR) engines, the pressure of the fuel in the filters was very high causing them to "lock" in place. I ran the engines for a few minutes prior. To heat the oil before changing. Could the pressure of the HPCR stay so high so long?

Help me, diesel dudes. This is all I've got left to do to wrap up this winterizing.
 
The strap is not very good on a slender filter. Get out the largest channel locks that you should keep on board. Try not to crush the filter.
 
Are you sure about the righty loosey thing...???? Mine are definetly righty tighty...the same as oil filters.

I had to use the same approach as Dave...the big channel locks.....now I keep them on board...grab as close to the rim (high) as you can. I you grab down low, or even in the middle, your chances of kinking the filter increase greatly.
 
I use filter pliers and not the strap wrenches. I find they are easier to use and get stubborn filters off better (and they crush the damn things if they refuse to cooperate).

Here they are:

item_Lg.asp


http://buy1.snapon.com/catalog/item...&group_ID=1535&store=snapon-store&dir=catalog

they make different sizes. I have two different size ones.
 
Larry-
According to the manual, they are regular threads (in that they didn't say they weren't:smt101), and there is nothing special to do re: the high pressure system. Once you do get the filters changed, be sure to read the part on priming the system before re-starting.
 
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I use Vice Grip locking chain pliers to remove secondaries and oil filters and while I've never had the occassion, they can be used to lock a free-wheeling shaft.

http://www.irwin.com/irwin/consumer/jhtml/detail.jhtml?prodId=IrwinProd100322

Like Dom said, I clamp it as high on the filter as space allows and loosen the filter to where I can finish it off by hand. And because I'm not good at balancing a full filter with one hand turned backwards at the wrist whilst standing on my head, I use an awl to punch a hole in the filter to allow the contents to drain into a basin before I remove it.

I can confirm that a CAT filter is definitely righty-tighty, and I do not believe there is any pressure on the filter end of a pressurized fuel system.
 
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Filter are the most commonly over tightened part. The threads are normal. I don't think the fuel pressure will affect it. These should be before the Common rail pressure pump to protect it. That would indicate they are seeing about 20psi from the lift pump.
 
Thanks guys, that's exactly the information I needed. Armed with this new knowledge and renewed confidence, I'm going to really lean into it.

The righty-loosy thing was just a theory. I'll be leaning-lefty and hopefully I won't break off a bracket or something.
 
I broke my large oil filter wrench trying to get mine off. I also had a struggle with the coolant filter, which had no lubricant on the gasket (note to Cummins Tech who installed them-thanks pal). What worked for me was a nylon strap wrench and a lot of muscle. I positioned the strap just below the top of the filter and applied enough pressure to break it loose. I wish I'd thought of the awl drain trick-I spilled a pint of diesel into the bilge when I dropped the 2 micron filter. Oh well. Bilge had to be completely scrubbed anyway. I forgot to mention that when the oil filter wrench broke I plowed my head into the oil filter mount on the port engine. Lots of colorful words starting with "F" and ending with "k" ensued, and some paper towels to clean up my forehead (no cool scars, regrettably) ...but DIY, and knowing it is done right, is half the fun of spring commissioning--when the engines crank up with no fuss and run all season trouble free-it is all good.
Shrink wrap is on. I am sad.
regards
Skip
 
An observation or 2..................the 2 worst things on a filter gasket are grease and nothing. That will almost weld them on in some applications. Use engine oil or clean fuel.

Secondary filters are usually on the suction side of the fuel distribution pump and are unbder vacuum, not pressure.
 
Dom,
I long for the day when my oldest, now 6, will be able to really help. He did accompany me into the engine room to swap out the generator impeller-the Cummins are as tall as he is on their mounts--and he thought that was pretty cool. My youngest, however, is the baot fanatic like Dad--today he asked if we could go on the boat instead of going to see the Grandparents for Thanksgiving.
After BIH he also asks my wife why we don't have a 480 Sedan Bridge like "Mister Gary"

That's my boy.

regards
Skip
 
When my son is on the boat while I'm in the engine compartment, he usually learns a new word or two...

-CJ
 
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