Why do secondary fuel filter turn black??? - Page 2 - PeachParts Mercedes-Benz Forum

bio350 · #16 03-23-2009, 02:04 PM

I had slime in the bottom of all my tanks. Cleaned the tanks, changed the tank filter, replaced the lines with Viton tubing and then added "Killem" to my tanks. It only takes a couple ml's per tank.
When I rechecked the tank filter, it was clean. The stuff works!!! I order mine on-line but I believe you can get it at Marine stores also.
If you have any fuel sitting in tanks you should also add some to your storage tanks or stored vehicles.

Diesel911 · #17 03-23-2009, 06:52 PM

Quote:

Originally Posted by babymog

Depends on who you ask.

In big diesels I've had, the primary filter is the one that does most of the filtering, regardless of the flow direction. Seems that Mercedes-US calls the first one in line the primary, even though it is not primary in filtration.

I know that it seems like the Filter that does the most filtration should be called the Primary Filter; but, In Trade School they told us if you had 2 filters installed the one closest to the fuel tank was the Primary filter (the 1st filter) and the filter further away from the tank was the Secondary filter (the 2nd filter).

Some Engines like my Volvo Diesel and the VW Rabbit Diesels have only one Fuel Filter on them.

Bentleyair · #18 03-23-2009, 07:08 PM

I just finished a Startron tank treatment and Startron fuel treatment (they are 2 different products). I found mine at West Marine. I had an immediate power increase and now I am repeating the treatment. The diesel fuel will grow if the fuel sits for extended periods of time. Normally the fuel that you purchase will not have the growth in it if it comes from a station that has a steady diesel business. Try to stay away from the stations that really can't handle the large diesel trucks to help with their volume. Also, there is a product used in aviation Jet fuel that keeps it from gelling and growing, it is call Prist. You may be able to find that in your local pilot supply store at the general aviaiton airports.

tangofox007 · #19 03-23-2009, 07:43 PM

Quote:

Originally Posted by Bentleyair

Also, there is a product used in aviation Jet fuel that keeps it from gelling and growing, it is call Prist. You may be able to find that in your local pilot supply store at the general aviaiton airports.

Prist serves only one purpose; it prevents water in fuel from freezing.

argus445 · #20 03-24-2009, 01:09 PM

Quote:

Originally Posted by Diesel911

I know that it seems like the Filter that does the most filtration should be called the Primary Filter; but, In Trade School they told us if you had 2 filters installed the one closest to the fuel tank was the Primary filter (the 1st filter) and the filter further away from the tank was the Secondary filter (the 2nd filter).

Some Engines like my Volvo Diesel and the VW Rabbit Diesels have only one Fuel Filter on them.

One thing i miss is the tank drain on bottom of the late 90's jetta's most of crude that settled on bottom u could just drain away

WDBCB20 · #21 03-24-2009, 03:30 PM

Having the car sit with little fuel in the tank is a good way to promote critter growth. They live were water meets diesel. Empty tanks allow condensation from tank walls to accumulate in the fuel and provide habitat.

You might also note increased power loss and stalling when fuel runs low which can sometimes be relieved by fueling up (dilutes the contaminated fuel with fresh fuel) until the filter finally clogs. Biobor is a fuel treatment you buy at marine stores.