Ok so lately I've been noticing a drop in my mpg and its too significant to be just from winter fuel. So after looking around the IP and the rest of the fuel system I noticed the water separator drain was wet with diesel. I just changed the filter about 1500kms ago and I thought at first that it was just diesel from draining it. I wiped it off and checked again today and its wet again . So could I have possibly installed the water separator wrong. I put the o-ring on it (new one) and put a bit of oil on it as directed when I installed it. I'm thinking I might've pinched the o-ring when I reinstalled the WS?

Any suggestions are appreciated

Lucas

 

Pull it off, rub some grease on the o ring and put it back together. Use channel locks to crank it on there pretty good because it will leak if not really tight.

 

Man, you talk about coincedence! Same EXACT thing happened to me today! I was almost at the changeout point anyway, so I pulled into the local NAPA and replaced. I was wondering about the new fuel...would this have anything to do with it? My sensor was hecka tight and it has been leak free since March. no more leaks after the replacement(knock on wood...There should be an icon for knocking on wood!)

 

I wouldn't be in a big hurry to blame alot of leaks on the low sulphur fuel just yet. We'll need a year or two of experience with it before we can even start to draw any conclusions there. In the meantime though, DO make sure you are adding something to increase the lubricity. ULSD is guaranteed to wreak havoc with pumps, injectors etc. without additional lubricity adds.

 

Mine does this too. I thought it was the water sensor leaking out somehow but after months of putting up with it, I replaced the sensor. It didn't stop the leak so.... upon further investigation I find that it is the gasket on the fuel heater right above the filter assembly. Check the lines and gaskets there. Might need to pull the throttle linkage bracket down to get a good look at it.

 

You know, it's advice like the ones given here that make this a great site. Helpin' a fellow brotha out!

 

And as long as you have that throttle bracket off go ahead and cut the back half of it off so you don't have to struggle with it next time you need to work with the fuel filter.

 

Mine 2 just started leaking at the WS below the filter.. Could it be the new fuel??? What kind of additive do u guys recommend???Thank U love this site!!

 

I'm gonna chime in here too. I just noticed the same thing on my old 89. I just had the injector pump redone and when I got it back I checked my mileage and it wasn't doing much better than it was before the rebuild. Upon further investigation I found that the fuel filter assembly was leaking and I replaced my filter. I did not put any oil on the seals (by the way, thanks I did not know that little tip) but I took it to a local service station today. If I find out anything I will post it on here for all to see!

 

I don't believe the sealing oring is of yesterdays material. there for i doubt, that the fuel is what is creating the problem......if it had been on there for awhile and just started leaking them maybe.

I really thing that are problem will be with the inj pump seal if they haven't be rebuild or don't have the viton seal in it!

 

O.K. I just heard back from the service station I had taken my truck to. The guy said that the plate that the fuel filter screws onto was loose. He said that overtightening the filter can cause the plate to loosen? When I replaced my filter a couple days ago it was very tight. I had to loosen it with an oil filter wrench. I do not know how or why overtightening the filter can cause the plate loosen up and leak but he said when he tightened it the leak stopped. Though I would pass it along for what it is worth!

 

If you tighten it more then hand tight (the filter) then when you loosen the filter(taking more effort to loosen then i did originally to tight)the extra effort could cause the fuel heater hosing to come loose and cause the fuel to run down the the filter and make it look like it's the water sensor at the bottom of the filter that is leaking!

glad to see it's fixed with out much hassle.

 

Me too. I like it when I can get by without spending a fortune. I hope this is all that was wrong with mine and I hope the other guys have an easy fix as well!

 

Add me to the leaky fuel heater club. I tightened it last time I changed the filter, but it's still seeping. Got the seal from Cummins today, but I think I'll wait for nicer weather (it's 45 with a 20 mph breeze).

 

You all don't think it's from pumping up either the power of these things through fuel, I mean that fuel demand exceeds factory specs which equal a leak at the most easiest way out... a rubber seal that is hand tightened? Does this jive with you all? Seems weird how all of a sudden after 7 months of leak free to just start leaking in that area, in my case. Maybe I should go to my local hose and fittings shop and invest in Viton O rings?