Why NO water fuel separator on my engine?

Indy Bob · 05-04-2019, 10:07 AM

I have a 2000 Ultimate Advantage 38K with a 330 Cat. It is the 3126B engine and it has 2 fuel filters. One on the engine. One in the back in front of radiator. The manual says "NO Water/Fuel Separator needed for that engine." The rear design really leaves no way to easily check or drain a filter. I use a fuel treatment "POWER SERVICE Diesel Kleen" on every fill. The CAT runs just great, but just wondering about the filter and if I should switch the rear to a combo drain.

Cataska · 05-05-2019, 08:43 AM

On our 2005 Itasca meridian the filter in the rear is the fuel water separator filter

PeteBar · 05-07-2019, 09:41 AM

Like Catasca, my 2001 Horizon w/ 3126B has a small plastic separator on the rear primary filter. Not sure it does much , in 17 years I have never seen anything in it.

Cataska · 05-07-2019, 06:51 PM

yes on the rear filter plastic bowl for inspection and draining

imnprsd · 05-08-2019, 02:18 AM

Check the part number on your fuel filters and I bet you will find they are both technically a "fuel-water-separator." At least that's how things are on my 2004 ISC-350HP Cummins.

Cat is known for having better filtration vs. Cummins so maybe one of your two filters is a fuel-water-separator and the other is a straight filter -- which is better. Pre-2004 Cummins engines also have an Accumulator Pump system and I think you CAT has a similar system. (Not sure.) This maybe why you have 2 fuel filters also. The first filter will trap algae (or other large particles in the fuel); and the second filter is just a second stage filter.

Note: Water-Separator Filters don't have as much filter material as a dedicated filter, in an RV time sitting is a bigger concern. This is when algae builds up in your fuel tank, which is why you should always fill your tank up full before you store your RV for the winter; and I suggest you add a biocide when your rig is in storage too. This stuff is very hard to find so I use Amazon.

https://www.amazon.com/Biobor-JF-Die...gateway&sr=8-4

Note: Cummins engines are very sensitive to fuel pressure so my #1 filter is 20u and the #2 filter is 10u. (And you don't want anything smaller or you will experience acceleration problems due to fuel starvation.) Your CAT may have smaller micron filters, but maybe not.

Get to know your fuel system design. Then you will better understand why you have 2 fuel filters. And be sure to carry an extra set of fuel filter with you; just in case you find your filters get clogged due to bad fuel. This could save you lots of time and tons of money by avoiding a tow when your engine does not start.

Also, I never fill up at a cheap Walmart or small town diesel pump. Honestly. Take it from me, who knows better now after a bad experience... you should spend the 10 cents more per gallon and buy your fuel from a well traveled diesel truck stop.

FIRE UP · 05-12-2019, 05:17 PM

Well,
Freightliner and CAT were all over the place in the early stages of 2000 to about late '04 and above when it came to fuel filters and, just how many and, whether or not one or the other, (if two) would have a water separator on them. When we purchased our '04 Itasca Horizon 36GD with the C-7 330HP CAT, I was almost surprised that it had only one fuel filter, on the back. And, after just a bit of research, I found it had NO WATER SEPARATOR on it. In some research, I found that Freightliner and CAT, had some discussions about the actual need of a second filter.

Well, as I've been lead to believe, by folks in the know, the "bean counters" won and, there were a few chassis's/coaches, mostly with the C-7s but, a few with the 3126 versions, that came with only one filter. Then, in the middle of a production year, there was a change and, from that point on, there were two fuel filters installed.

So, I looked up the parts/filter and separator and, ordered things up. Ever since, all my fuel filter changes involved a new filter WITH a water separator on it. Have I ever seen any water in it, NOPE , not at all. But, it's there just in case.
Scott

CharlesMoore · 05-16-2019, 04:04 PM

So, I looked up the parts/filter and separator and, ordered things up. Ever since, all my fuel filter changes involved a new filter WITH a water separator on it. Have I ever seen any water in it, NOPE , not at all. But, it's there just in case.
Scott[/QUOTE]

What is the CAT 330 fuel filter with the "water" plus diesel part number?

FIRE UP · 05-16-2019, 10:44 PM

Quote:

Originally Posted by CharlesMoore

So, I looked up the parts/filter and separator and, ordered things up. Ever since, all my fuel filter changes involved a new filter WITH a water separator on it. Have I ever seen any water in it, NOPE , not at all. But, it's there just in case.
Scott

What is the CAT 330 fuel filter with the "water" plus diesel part number?[/QUOTE]

Part number of a CAT filter with a water separator, not a clue. I use WIX filters on ours. 33783 is the WIX number for our C-7.
Scott