Cat 3126 Racors

[Jaws]

I was helping a friend this weekend by changing out the Racor filters on his '99 450DA with 3126 motors. The selector valve was at the "BOTH" setting before I started. When I removed the filters I was surprised to see that he had a 30 micron in one canister and a 2 micron in the other on each engine. My Cummins motors have 30 microns in all four canisters with 2 micron on-engine primary filters.

His previous service was done by a professional diesel mechanic last season and he has not touched that set up since then.

Anyways the 2 micron units were really black and the 30's weren't as bad. I re-installed with all new 30's like my boat, since I only had those filters on hand from the "boatfilters" outfit. His primary, on-engine Cat filters are 2 micron similar to mine.

Should I have dropped two different filters on each side? Or keep them both at 30's? What are your opinions? We're boating in Lake St. Clair.

James

 

[Dancin Dave]

no opinion, 2 of the same microns in the primaries I use 30 microns and the secondary spin on is the 2 micron cat filter

 

[fwebster]

The selector set on both and 2 different particle trap sizes makes no sense.

Everyone has their own ideas on Racors, but I've used 30 micron (2040-PMOR) in both Racors with Caterpillar 1R 0750 (0751) high efficiency 2 micon engine mounted filters for 12 years with absolutely no problems.

 

[Dancin Dave]

Amen

 

[douglee25]

Maybe the mechanic was being overly cautious to eliminate a possible cause for a previous problem?

Doug

 

[Jaws]

Thanks for the replies, everyone. I agree that having two different filters in the Racor units and having the selector valve at "BOTH" just didn't make sense. I'll try to find out what the mechanic was thinking and let you know if I can get an answer.

Not to hijack my own thread but after I changed out all my own engine filters (Racors 30's, on engine 2 microns, oil, coolant), I treated the motors to new Walker (K&N) air filters and crankcase vents. It says in the instructions that you can clean and recondition them up to three times. F.Y.I.

James

 

[pacopico]

With a (2) micron in one filter housing, and a (30) micron in the other, and the manifold switched to "both" what will happen is this:

The fuel will initially flow through both filters until the (2) micron filter suction restriction exceeds that of the (30) micron filter...which is relatively quick.

Then the (30) filter will continue to be the one in "effect" in the fuel circuit.

Realistically there is no reason to have a (2) micron filter in the primary filter location as they will plug rather quickly, especially when fuel is not very clean.

The blackness on the (2) micron filter is normal when the filter is plugged/dirty.

Cheers!

 

[Asureyez]

WOW, somethings never cease to amaze me.

The dual particle filters are nonsensical, and accomplish little in the system for this ebngine type.

As we have been told the previous mech was a "professional" as in "experienced" so we have to assume the filters were used on what was available decision basis. He would not have wanted both 2 Mic's on one engine and 30's on the other, nor would he have wanted to leave one filter empty on each side and cut out until a proper filter was available for the empty side as that would have caused a second trip.

So he did the logical thing, mixed them for each engine, got paid and ran like any professional would do!

Hindsight is crystal clear!

 

[The Bill Collector]

I have CAT 3126 and the dual racors. My mechanic has sworn me to use 2 micron all around and keep the selector switch to both. I average over a hundred hours per season on the racors before replacement. The mechanic states it is a lot cheaper to swap out a paper filter on your racors then the injectors on your CATs....

 

[tobnpr]

I have CAT 3126 and the dual racors. My mechanic has sworn me to use 2 micron all around and keep the selector switch to both. I average over a hundred hours per season on the racors before replacement. The mechanic states it is a lot cheaper to swap out a paper filter on your racors then the injectors on your CATs....

There's no clear answer-even from CAT- as to which trap size to use in your primaries. I called CAT customer service after buying my boat because everyone (including members of this forum) has a differing opinion. According to CAT, 30 mic is fine- and 2 mic is fine.

My mechanics told me the same thing yours did, and they called their 3208 "guru" (ex Ring Power) who confirmed their opinion- 2 mic trap size in the Racors. I don't think you'll find anyone else here who uses them- most use 30's. The Racors are so easy to change (and I have them fitted with vaccum gauges) that I don't mind an extra change-out during the course of the year.

 

[Jaws]

As Frank mentioned, there are a lot of opinions but the 30 micron as the first filtration and ending with a 2 micron seems to be a popular way. If you're not already a member, check out Tony's articles on boatdiesel.com regarding diesel filtration. He advocates even more steps using Fleetguard filtration rather than Racors. In fact a clean 2 micron filter will pull the same as a 10 micron when new, less than 0.5HG. But, a 2 micron will load up faster and you'll change it more often.

But the point of all this is that these Racor units were loaded with different filters and set to "BOTH". I think Chad hit the answer on the head. I'll check at the marina this weekend and see if I can find out why they were set up this way. I just wasn't sure if it was a great CAT secret that Cummins guys weren't allowed to know.

James

 

[Dancin Dave]

I run all season on 1 secondary spin on cat filter. Maybe the mechanic mistakingly put in the 2 micron racor.