DAHL fuel filter change?

Hi all, we are new owners of an IP27 sailing the Great Lakes. This boat came from the factory with a DAHL 100 fuel filter/water separator. I have had all Racor in the past and I'm not familiar with the brand. I did manage to find filter elements through Amazon as none of our local suppliers had anything, after the fact I discovered that they are also available through NAPA Auto Parts which is a plus. Our system is set up so that the electric lift pump pulls the fuel into this filter, then pumps it through the Yanmar filter to the mechanical pump, then to the injector pump. The owners manual which I now have thanks to IP Customer Service does not have any instructions on changing the filter. I have no idea the last time it was changed, the previous owner is not very forthcoming with information, I'm not sure he knows either as he paid to have everything done to the boat. Any tips on changing this filter and minimizing air intrusion into the system??

Hayden, thanks for the info. Two things...When you replaced it did you change the plumbing around as well or keep the setup as it was from the factory??

Second, in the mean time can you clarify "bleed the fuel line downstream"? Are we talking the Yanmar filter or all the way to the injectors? Can I use the hand lever on the Yanmar fuel pump?

Craig

Hayden, thanks again. This is not our first Yanmar, but certainly the first set up like this. I guess the logic of placing the lift pump after the filter would be to run filtered fuel through the pump. I just wonder if the electric pump will lose prime once that air in the top of the filter goes on down the line. I was not going to try and start it until the air was out, but thought that perhaps just turning the key to "on" and powering up the lift pump (with a rag over the low oil pressure alarm) would be a way to avoid a hundred strokes on that Yanmar pump lever and pump the air to the return line and back into the tank.

I appreciate all the information and your patience with my questions.

Craig

Glory, did you change your filter? How did it go with the bleeding.

I just purchased the Racor 500. I have an older racor with the spin on canister at the bottom. You might note that the fittings are 1/2 inch and do not come with the filter, so you will probably need to order those also.

An update would be appreciated!

Keith

Hi Keith, no I have not changed the DAHL filter yet. I decided to wait another few weeks until we haul out for the winter. The weather here on the North coast has been pretty poor with one round of rain and wind after another. The fronts have been sweeping down out of Canada and pretty much shutting down boating. Rather than spilling diesel trying to change the filter in the slip, it is easier to let the boat sit and do it on the hard. With small craft warnings every weekend we are going nowhere.

I will update you when it's done.

Craig

Well, the season is about to get going and I couldn't put this off any longer. I changed out the DAHL filter this past weekend and it was as much a pain as Hayden said it would be. I printed off the instructions from the DAHL website and read them several times before doing the actual change. Step one, which was to put a container under the filter, open the petcock and drain the filter did not work. Opening the petcock got you about a teaspoon of fuel out before the vacuum took over. In order to get the filter to drain I had to get a wrench and loosen one of the fuel lines on top of the housing. That let air in and the fuel out the bottom. After that it was pretty straight forward and a major mess to change the filter element. BTW, the elements are available on Amazon for about $9 each. It appeared that the one on our boat had been changed before, but not recently as it was full of sediment. I filled the filter up to within an inch or so of the top with diesel per instructions, reassembled it and then the mess really got out of hand. I ran the electric pump for a minute maybe, using a folded up rag to silence the low oil alarm. Then I wrapped the Yanmar filter with rags and opened up the bleed screw, ran the electric pump for maybe 10 seconds to bleed the system. You would be surprised how much fuel comes out of that bleed screw in that short of a time. More than a half dozen shop rags can absorb for sure, that made a nice puddle under the engine. It actually took longer to clean up than it did to change the filter. I also made sure all the fuel lines were tight, the one leading into the Yanmar filter housing was actually loose. All that said, a Racor filter is on the future list for sure, although DAHL says the filter only needs to be changed every 500 hours which is a bout a lifetime for us.

I checked the boat yesterday and there was a small puddle under the filter. I used a paper towel to check the sides, nothing. (the red dye in off-road diesel really shows up on a white paper towel) It appears that the fuel is coming from petcock. According to the Dahl website, that petcock is a non-marine item that screws into an adapter that screws into the fuel bowl. I see additional possibilities for leaks there. The obvious answer is to replace the filter however we are already three weeks behind on the lift in prep and it looks like the weather window for working on the boat closed with rain and snow predicted through Saturday.

Glory wrote: I checked the boat yesterday and there was a small puddle under the filter. I used a paper towel to check the sides, nothing. (the red dye in off-road diesel really shows up on a white paper towel) It appears that the fuel is coming from petcock. According to the Dahl website, that petcock is a non-marine item that screws into an adapter that screws into the fuel bowl. I see additional possibilities for leaks there. The obvious answer is to replace the filter however we are already three weeks behind on the lift in prep and it looks like the weather window for working on the boat closed with rain and snow predicted through Saturday.

here's a wish for pictures of your projects so I would have a better idea of your rig.
You are sure the leak is not coming from the feul line you loosened and then retightened? Probably not but giving it a little extra turn with a wrench might not be a bad idea just to be sure it ceded well or back it out and do it again but that would let air do your system which sounds like a pain in the butt.
Have you run the engine yet? I wonder if you're bleeding was successful. On my 3GM, there is more than one screw that you have to loosen to bleed appropriately. One is a rather sneaky spot forward of the bleed screw over the engine mounted feel filter. Although I had the engine manual, it did not make it plain, I was fortunate enough to have someone familiar with the engine to show me the sneaky spot. If you have the same engine as I do let me know and I will include a picture of the other bleed screw between the fuel filter bleed screw and the fuel injectors.
I am not sure about the layout of a 27, and I do not have good will access here off of Cumberland Island to pick it up, but are you able to cut an access to the side of your engine through your quarter birth? It is very easy and u will see the inside of my opening hatch next to the fuel filter below.
Do not forget to order the appropriate fittings for the Racore fuel filter when you order it. Do not hesitate to call the customer rep if needed. They might helpful. I did not call customer rep so cannot attest to that.

The 27 is opposite the photo above in that the fuel filter is mounted on the portside of the compartment. I do like the idea of another access hatch though, I will need to take some measurements to see if that is actually an option. As I recall the 27 q-berth does not have the depth, I don't know if a large enough access could be made to be worth the effort. A measuring tape will answer that question though. The exhaust system is also on that side of the compartment so I would have to measure and see how much is blocked.

To answer your other questions, yes, I did check that fuel line and it is tight, the top and sides of the filter are dry so that leaves only the petcock. What I was thinking is that in the process of opening and closing the petcock I may have also loosened it by turning in the threads? It was a difficult little lever to move. On our 2GM I am not aware of any other bleed screws in the fuel system, my manuals are down on the boat so I can check those on Friday as well.

I ordered replacements for the petcock, bowl plug and gaskets. All were installed last Friday with no change. I'm thinking that perhaps the bowl itself is cracked where the bowl plug screws in. In any event, I have had enough with this unit, a new Racor 500 is on order and should be here Thursday. I was hoping for an easy fix but I'm tired of throwing $50 bills at a filter that is hard to work on and hard to find filter elements for.

What fittings do you need?

I'm going to try and adapt the DAHL fittings to the Racor. Fortunately there is a place down the street from us that specializes in fittings and hoses. The DAHL is a 9/16 where the Racor is a 3/4, we are going to either adapt the fittings to the 3/4" or replace the fittings with 3/4" to hose barb and just cut the lines. Easiest cleanest would be to adapt the old fittings of course.

It appears that there wasn't enough water in the fuel bowl to see but there was enough to seep down into the threads of the plug on the bottom. That water must have frozen over the winter and caused hairline cracks in the bowl. That wasn't easy to see until I removed the whole assembly. I don't see how this could have been avoided because opening the petcock would not have allowed any water around the plug threads to drain off.

Hmm, need to move the boat to a climate that doesn't freeze in the winter! Wink