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New PowerTech 10Kw Primary Fuel Filter

March 12, 2021, 12:48:08 pm

The next thing on my list of maintenance items on our PT 10Kw generator was to install a new primary filter to replace the 34 micron filter the in the base of the electric fuel pump. I ordered a 10 micron filter off ebay for about $20. On arrival, it looked good so I fabricated a mounting plate for it. I had a choice of making the filter the first stop from the fuel tank or plumbing the supply hose to the electric fuel pump first and then through the filter. I chose the latter as I didn't want any possibility of sucking air into the fuel system. Glad I did as the four ports on the filter are not tapered pipe and leak. Working with only the top body, I carefully tapped the ports with a new 1/4" NPT tap taking care to blow all chips away several times on each port. Brass tapered plugs are installed on the two unused ports.

I sealed the threads with paste rather than tape. I added an all stainless ball valve so any filter or pump work can be done without siphoning fuel out of the tank. I valve is extremely well done with a sliding collar so it locks in either position. No possibility of accidentally shutting the fuel off and it even has a hole to allow a clip or small lock to be installed.

The existing primary filter in the base of the electric fuel pump can be accessed with a 7/8" wrench. The new one in the bag is the standard filter for all cylinder type Bendix, Facet or Asian electric fuel pumps as used in small planes, boats, RVs, etc. The big drawback in the electric pump filter is that there is no way to visually check for water or algae. If it passes water to the secondary filter, it will eventually rust through the bottom. This frequently happens on diesel car secondary filters. This was the reason I installed the new filter assembly. I did order two additional 10 micron filters.

Mounting plate is 1/4" thick with two 1/2" stainless bolts and washers taking a 3/4" socket/wrench. The filter mounting fasteners are 5/16" stainless. The ball valve handle has to be removed to rotate it into the existing fitting.

After installation, there are no leaks but the pressure has dropped about a half pound on the secondary gauge.  Filter source: Brand New R12T For Boat Marine Spin-on Fuel Filter/Water Separator 120AT | eBay

Pierce

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Re: New PowerTech 10Kw Primary Fuel Filter

Reply #1 – March 12, 2021, 01:26:27 pm

Two additional photos that didn't attache for some reason.

Couple of tips: When filling the new filter, open the "T" handle valve and put the switch in the "glow" position until the filter is full then close and start.

If you ever have trouble with the generator running and then dying, open the T handle valve part way to allow air to go go back to the fuel tank. I showed pressure at the gauge but the generator died. A new filter did not cure it but then I tried the valve. A good stop gap measure until you can replace the feed hose from the fuel tank.

Pierce

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Re: New PowerTech 10Kw Primary Fuel Filter

Reply #2 – March 13, 2021, 03:05:18 pm

Excellent upgrade Pierce! 

If you shut the valve off after running will that keep air out between the valve and the secondary filter for the next start?

Jerry

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Re: New PowerTech 10Kw Primary Fuel Filter

Reply #3 – March 13, 2021, 03:54:06 pm

Good question Jerry,

No, I only put the new valve in the line to make it more convenient and less messy when checking or changing the filter in the bottom of the electric fuel pump or changing the spin-on secondary filter. The other valve is a T handled valve on the return line. It's used after any maintenance is done to get all the air out of the system. Without the T valve being used, the electric pump does not produce enough pressure to push air past the spring loaded return valve (fuel back to the tank) so the fuel pump just slows the clicking sound but the air is still trapped. When you open the T valve, you can hear the electric pump speed up and should let it run like this for 30 seconds or so to purge all the air.

Not all Foretravels with the 10Kw generator have the valve. I remember looking at Bill Chaplin's U300 and wondering why it didn't have the valve.

Some Foretravels will have the little square electric pump. In this case, they may have one of those tiny clear filters used as a primary filter. I had one of the square pumps develop an internal leak and let air into the system.

I read all the negative reviews on many on the Chinese filters. Wondering how they could make so many faulty parts, especially after looking at the quality/machine work our new filter, it's easy to see that the metric tap they use on the fittings is not compatible with the tapered NPT we use, so on any aftermarket filter, it's important to run a tap in to make sure the threads will work.

When I was thinking of putting the filter before the fuel pump, I pressurized it and no matter how much sealant I used, the supplied plugs in the unused ports leaked (before I re-tapped them). Thinking that it's not a bad idea to put the fittings in place and use a Mity-Vac to check for leaks.

Ford's fuel filter/heater/sensor unit on their 6.9 and 7.3 was famous for leaking like a sieve and making starting difficult. When I put the 7.3 in the SOB, I round filed the whole unit and just installed a spin-on fuel filter on the firewall. Worked great. I think that is what is responsible for the majority of the difficult starting the IH/Ford diesels.

I think the biggest advantage with the new filter on the PowerTech is the clear bottom. So easy to glance at it when checking the oil, etc. Very few owners are going to pull the bottom off the fuel pump to check for algae/dirt so you are just crossing your fingers that you don't have any contamination in there. In fact, I bet 99% of owners don't even have an idea that the filter is in there.

Foretravel also put different sized fittings on the tank and the generator on the feed line on our U300. The tank had a 3/8" and the generator 5/16" fittings. I know it was not the P.O. as the spouse said they did zero maintenance on the coach before we bought it. Either 5/16" or 3/8" fuel line will work fine for the supply and return lines but the fittings at the ends must match up to the hose size.

Pierce



 

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Re: New PowerTech 10Kw Primary Fuel Filter

Reply #4 – March 13, 2021, 04:58:59 pm

Pierce,

 Very easy to service in that location.

But, assume no problem with engine vibration there??

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Re: New PowerTech 10Kw Primary Fuel Filter

Reply #5 – March 13, 2021, 07:06:29 pm

I looked at a couple of other spots including the wall on the left but the generator could not be moved with it there. Moving the fuel pump and installing it there was another but that would be a lot more work. I also could have installed a bracket on the tray in front of the left generator mount but went with a piece of 3"x10"x 1/4" steel bar as it does not flex and pretty vibration free. I do have to move one steel fuel line slightly away from the right side of the new mount.

Another factor was the generator is never at idle and after startup, goes immediately to 1800 rpm where there is not much movement. A lot of vehicles including our U300, Ford 7.3, etc mount their filters on the engine.

I have a fuel hose that will run off the fitting on the see through bottom so I can drain water out without making a mess. You can also look up and see the inside of the filter and since it's on the intake side of the fuel flow, anything on the white element will be visible.

In case of a leak or small fire, I can also turn off the fuel supply. Before this, there was no way to stop the fuel from siphoning from the fuel tank other than pinching the hose with a Vice Grip or C clamp. With a full fuel tank, the hose is a couple of feet below the liquid level. This computes to 0.75 psi for two feet of head with diesel.

The fuel fittings on the Isuzu engine are also metric and compression fittings won't work.

Good points Brett!

Pierce

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