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Helping JimT out with an inframe ... - Printable Version

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RE: Helping JimT out with an inframe ... - SquareOne - 09-23-2020

(09-22-2020 )JimT Wrote:  ....Finally replaced my Davco unit. Forgot to bring it with me down to Rawze's so I changed it out today. It was getting to the point where the fuel level wouldn't stay above the bottom of the clear housing. No matter how much I filled it up, after a day of driving it would end up down just below the clear plastic. Installed the new one, bled the air out and we'll see how it does tomorrow....

By any chance, did the old unit ever return to a normal level as the restriction increased? Mine will do the same thing once I install new filters. It will actually take a few thousand miles before it returns to the bottom of the clear housing.

The level will then rise based off the restriction created from the filter catching contaminates. I typically change it about 3/4 the way up the clear housing rather than wait all the way to the black 'change filter' line near the top.


RE: Helping JimT out with an inframe ... - JimT - 09-26-2020

(09-23-2020 )SquareOne Wrote:  
(09-22-2020 )JimT Wrote:  ....Finally replaced my Davco unit. Forgot to bring it with me down to Rawze's so I changed it out today. It was getting to the point where the fuel level wouldn't stay above the bottom of the clear housing. No matter how much I filled it up, after a day of driving it would end up down just below the clear plastic. Installed the new one, bled the air out and we'll see how it does tomorrow....

By any chance, did the old unit ever return to a normal level as the restriction increased? Mine will do the same thing once I install new filters. It will actually take a few thousand miles before it returns to the bottom of the clear housing.

The level will then rise based off the restriction created from the filter catching contaminates. I typically change it about 3/4 the way up the clear housing rather than wait all the way to the black 'change filter' line near the top.

Well, I must have some super clean fuel right now cus the new unit is still doing the same thing. Fill it up and over the course of a day's driving it works it's way down just below the clear housing. It concerns me being that low, keep thinking I'll hit a bump and suck up some air. Might look into the lines to the tanks, just to make sure there isn't some restriction there or maybe bad vents or something.

Either way the old Davco unit had to go. It wouldn't fully seal unless I torqued it down WAY more then the mfg stipulates. It just had too much abuse over the years.

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Oh, after pulling my first load yesterday I finally got the exhaust hot enough to burn off the Corroseal. Oh well, it was an interesting experiment. Looks like it can withstand a few hundred degrees no problem, but not the full range of temps seen by the exhaust manifold. Put over 1,000mi on it bobtail running bewteen 1600-1800rpm from GA to CT without burning it off or even causing any discoloration.

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Coolant level has stabilized, but I found a small leak from the new drain fitting we installed under the truck.

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Boost pressure... Bobtail I couldn't get it to go higher than 20-22psi. With my empty flatbed it topped out around 25psi. So, I removed the little egr block plate on top of the intake manifold (there's also a plug in the exhaust manifold). That seemed to help a bit, I don't think it was sealing properly. I think I might put it on the passenger side instead. Should seal up the crossover pipe while leaving the EGR side somewhere to leak if the pressure builds up too much (heat expansion). Now loaded I've been able to get the boost to max out around 30psi a few times. Still not perfect, but that's about where it was prior to the rebuild and I've known for a while that my CAC has a small leak on the passenger side where one of the mounting bolts is located. Considering I typically drive around using 5-10psi, 15-20psi pulling grades, it should be fine for now.

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Ran a few loads this week and now the poor engine is covered in a thick layer of dust from the dirt lots :/ Outside is pretty dirty too. Guess it's bath time this weekend!


RE: Helping JimT out with an inframe ... - tree98 - 09-26-2020

I have a davco on 2 trucks and they are always below the clear housing when I replace the filter until they get some time on them and the filter plugs up on the bottom then the level rises. I've played around with both trying to get the level higher but never worked. Now I don't worry about it.


RE: Helping JimT out with an inframe ... - JimT - 09-26-2020

I've never had the level sit this low before. It's like there's a very small amount of air finding it's way into the system somewhere. If I fill the Davco up with fuel it takes 1-2 full days of driving for the level to drop down below the clear housing. This only started happening recently so there's obviously something that's changed. When I looked at it last night the fuel level was actually just below the metal bottom of the filter itself, barely above the level where the fuel lines connect.

Sitting here thinking about it, I remember when I changed the Davco unit on Tuesday that of the 2 fuel lines, the one going to the primary filter had some residual fuel in it, but the one coming from the tank didn't. Just another reason to inspect the supply lines and the tank vents. Could be a small pinhole or crack forming in one of the lines letting some air in, or plugged up vents causing a restriction (and still sucking in air from some tiny crack).

One final thing, not sure if it's related, but I noticed yesterday that the fuel level sending unit seems to be going bad as the fuel gauge started bouncing around randomly. Maybe it's time to just replace the sending unit, vents and all the tank fuel supply lines.


RE: Helping JimT out with an inframe ... - Rawze - 09-26-2020

maybe pressurize the fuel tanks to about 10-15 psi and let it sit a while.... maybe you find a fuel leak in one of the pick-up lines.


RE: Helping JimT out with an inframe ... - Lonestar10 - 09-26-2020

what i would think looking at how the fuel flows into and outn of the davco for davco to have low level due to air your truck would run like poop. what it could be is there is a restriction from the tanks to the davco causing the fuel pump to have to suck harder which would pull fuel through less of the filter due to the extra vacumm


RE: Helping JimT out with an inframe ... - Chamberpains - 09-26-2020

I would also make sure your filter is sealed on the seat. And make sure its the proper micron rating for it. If its ti high of a number it'll never plug cause it not doing its job.


RE: Helping JimT out with an inframe ... - JimT - 09-26-2020

Gonna explore the fuel issue as soon as possible...

Unfortunately I blew a drive tire on the way home and I'm still waiting on the road service guy to get out here. Didn't have many choices for tires. Closest place that I found that had our national tire account was a TA an hour away. Called it in at 5:15pm, said it would be 3.5 hours before they get here... well, it just hit 4 hours and he JUST CALLED to say he's leaving the shop now!!! !@#$#@!@#$#@!@#$ To top it off the "best" tire they had in stock (with the national account) was a Bridgestone M726EL. I guess it'll match up just fine with my 7 other mix and match recaps that the dealer had on here when I bought the truck 2 years ago. I'll probably wait till the spring and look at replacing all 8 drives, keep the M726EL as a spare. Tread depths of the other 7 are all between 7/32 and 9/32.

Probably the worst part is the damage it caused. Blew off the front half of my full plastic fender, bent the 1" 10.9 steel bolt that holds the fender bracket to the frame and destroyed the steps on one of my new step boxes. "Luckily" the steps absorbed the impact and left the box itself 99% undamaged.

Haven't made a yet dime since the end of July. They almost didn't approve the tire purchase because I owe Landstar for 8 weeks of normal deductions (mostly insurance/trailer rental). Boy, a trucking business sure is fun!


RE: Helping JimT out with an inframe ... - Rawze - 09-26-2020

that sucks ... thats why i don't run re-caps on my truck.