- Mar 25, 2008
- 5,522
- Boat Info
- 2006 Sea Ray 58 DB
- Engines
- MAN CRM V8-900s, Twin Disc Drives; Onan 21.5 Generator
On the 8.1 Oil Change Thread, Scottster asked about changing the inline fuel filters. This would apply to ~'01 to ~late ‘05’s/~early '06 8.1s without the latest cool fuel module. For example, Scott F, with his '07 8.1s, and Windjammer with his '06 8.1s both have the latest cool fuel modules which do not have a spin on or inline filter. The following applies to my ’05 340, but I bet it applies to all the 8.1s in the above mentioned year groups.
First - Changing the spin on. I used the OEM Mercruiser Water Separating Filter (P/N # 802893T – about $10). Just like the OEM oil filters (which have the ADVs), I preferred to use the OEM water separator filter. More on OEM parts in a minute. MM put them on so tight in my 200 hr check last year, that it took two oil filter wrenches (one with my son pulling and one with me pushing with my foot) to get them loose. After we broke them loose, I used a wide mouth jar to catch the fuel that will spill out. Two purposes here – one, to prevent the spill, and two, to examine the condition of the fuel held in the filter. My filters held no water – I try to keep my tanks full. On a previous boat, I did not, and each year the water separator filter would have about an inch of water in it. Fill the new filter with fuel, oil the gasket, and reinstall – I used the “hand tighten ¾ of a turn after gasket contact” method of tightening.
Second – Changing the Inline Filter. The Mercruiser P/N # is 35-864572. I found these for $55 each. Now for the OEM discussion. Here is an AC Delco GF652:
This filter is GM OEM for many of their small and large block truck/SUVs - $6 from Autozone. This is what our inline filters look like. In each female end, is a double male nipple, which is connected to the in and out fuel lines by compression fittings.
All you have to do is loosen the compression fittings one flat, and then you can take them off by hand, and then the entire filter, with its double male nipples can be removed. Unscrew the double male fittings, use gas proof Teflon tape or gas proof pipe dope (both yellow), install the double male nipples in the new filter, reverse the above process and you are done. A small amount of fuel will come out when you crack the compression fittings one flat. When you remove the filter, hold it horizontal, then dump it from the “inflow” end into a clear jar for fuel examination – mine had a lot of dirt/junk in it – the filter did its job. I installed the $55 OEM filter this year, but I’m going to take on of my old ones to AutoZone and compare it to the AC Delco GF652 (AutoZone P/N # FF 3504).
The starboard engine was easy to do using the above method, but for the port engine I found an easier way (I think so anyway). I loosened the filter “inlet” line compression fitting one flat. Then at the fuel pump inlet, I loosened and removed the line that runs from the filter to the pump – this is another compression fitting; loosen it one flat and remove it by hand. Then sitting aft of the engine, easily turn the entire fuel line (about one foot long) CCW and withdraw the fuel filter. You only need finger pressure on the inlet side compression fitting to keep it from turning. Now swap the fittings as described above and reverse the process. Here is a picture of the fuel pump inlet compression fitting (Between 19 and 20 – 20 is the one foot long fuel line from the inline filter outlet to the pump inlet): Sorry - Can't get the PDF to post - it's page 5A-6 in the Mercruiser 8.1 Service Manual.
First - Changing the spin on. I used the OEM Mercruiser Water Separating Filter (P/N # 802893T – about $10). Just like the OEM oil filters (which have the ADVs), I preferred to use the OEM water separator filter. More on OEM parts in a minute. MM put them on so tight in my 200 hr check last year, that it took two oil filter wrenches (one with my son pulling and one with me pushing with my foot) to get them loose. After we broke them loose, I used a wide mouth jar to catch the fuel that will spill out. Two purposes here – one, to prevent the spill, and two, to examine the condition of the fuel held in the filter. My filters held no water – I try to keep my tanks full. On a previous boat, I did not, and each year the water separator filter would have about an inch of water in it. Fill the new filter with fuel, oil the gasket, and reinstall – I used the “hand tighten ¾ of a turn after gasket contact” method of tightening.
Second – Changing the Inline Filter. The Mercruiser P/N # is 35-864572. I found these for $55 each. Now for the OEM discussion. Here is an AC Delco GF652:
This filter is GM OEM for many of their small and large block truck/SUVs - $6 from Autozone. This is what our inline filters look like. In each female end, is a double male nipple, which is connected to the in and out fuel lines by compression fittings.
The starboard engine was easy to do using the above method, but for the port engine I found an easier way (I think so anyway). I loosened the filter “inlet” line compression fitting one flat. Then at the fuel pump inlet, I loosened and removed the line that runs from the filter to the pump – this is another compression fitting; loosen it one flat and remove it by hand. Then sitting aft of the engine, easily turn the entire fuel line (about one foot long) CCW and withdraw the fuel filter. You only need finger pressure on the inlet side compression fitting to keep it from turning. Now swap the fittings as described above and reverse the process. Here is a picture of the fuel pump inlet compression fitting (Between 19 and 20 – 20 is the one foot long fuel line from the inline filter outlet to the pump inlet): Sorry - Can't get the PDF to post - it's page 5A-6 in the Mercruiser 8.1 Service Manual.
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