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The only reason I don't run a sump is because I sometimes drive through the sage brush or over fallen trees. I don't want the fuel line or sump getting snagged and ripped off.
The only reason I don't run a sump is because I sometimes drive through the sage brush or over fallen trees. I don't want the fuel line or sump getting snagged and ripped off.
Hardline and/or skid plate?
Originally Posted by HD Rider
Did you ever get this sorted out?
Not really. I drained the tank the other day (All 30+ gallons....) I got a huge amount of plastic shavings, and they kept plugging the little 1/8" drain hole in the bottom of the sump.
I then took a look at the Racor. I wasn't going to, but I decided to pull the bowl to empty it out. As it turns out, the o-ring was not in the right spot, I think? It was riding in a groove about 1/4 up from the lower flange. It came out of the box that way, and it looks like it belongs there. However, I decided to try moving it all the way down to the flange. The filter bowl now screws in to the base much more easily. The bowl is definitely threading into the base further, and it seems to have brought the bottom of the bowl closer to the bottom of the filter/screen.
Previously, I could not see the o-ring with the bowl screwed in. Now, the o-ring is visible, and is clearly sandwiched between the bowl flange and the mounting base. Is this how it should be? Can everybody see the o-ring when the bowl is installed?
Anyway, this seemed to have reduced the problem a little. I refilled the tank without dropping it, as I had to use the truck. I am also waiting on new tank straps to arrive first.
On Thursday, I pulled the inlet valve off, to see about possible restriction from the valve design. Its not a "full flow" valve, but the opening is the same size as the 3/8 ID fittings/hose, so it should ok. I had another thought about the valve though. I suspected that maybe the valve stem was causing a vacuum/air leak. I removed the ****, and jammed a vacuum cap over the valve stem. It was an odd shape, so it didn't quite seal, so I used my old friend RTV. Again , this seemed to help a little. At times, the visible "foam" was nearly gone. I noticed, by accident, that wiggling/re-positioning the hose from the sump to the racor would start/stop the foam. I found a spot it "liked" and re-secured the hose there for now.
I also played with the shutoff valve on the outlet side of the Racor. If I partially close/restrict the outlet, the liquid fuel level in the Racor rises, and foaming is reduced. Re-opening the valve fully, lowers the level, and increases foaming. Again, I would say it looks like the pump is pulling fuel out of the Racor faster than it refills, which really doesn't make any sense. The feed line from the sump is 3/8". The outlet to the pump is 5/16.
I'm thinking about just getting a FASS/Airdog, or making my own. Whatever I do, this needs to get fixed quickly, and cheaply. I just got an eviction notice, so I really need to stop worrying about the truck, and focus on not being homeless or losing all my things. On the other hand, I can't ignore the truck, as I need it, and I can't afford to break it.
Skip the Black RTV (did you see my post of it being unsuitable for fuels?)
Instead of any type of teflon, get some Gasoila. Better and designed for fuel.
May as well do it right and rule those out at the same time
Your link was for BLUE RTV, not black. The black is much more oil /chemical resistant. Also, its unsuitable for "gasoline", not "fuels". Gas is much more powerful solvent then diesel, due to the greater concentration of light hydrocarbons. The BLACK RTV is highly oil resistant, and diesel fuel is really much closer to oil, chemically, then gasoline. Think about it. Dip one hand in a bucket of gasoline, and the other in a bucket of diesel. Which one hurts? Which one dries/cracks your skin? Hold each hand to your nose. Which one makes you want to pass out?
And again, I'm only using it here as a secondary barrier. Its not the primary seal against pressurized diesel (Although it would work for that too, within reason.) It is just a "backup" to ensure there is no small air/vacuum leak.
As for the Teflon, the general consensus is not to use Teflon TAPE, as a piece could break off and clog something. However, I am using a liquid teflon based thread sealant.
Which is exactly what Gasoila is: Pipe Thread Sealants - Products
PTFE is Teflon. They only offer 2 thread sealants without it. 1 is specifically for sealing special fiberglass pipe used for DEF fluid. The other is for food-grade uses, and you'll see that it is rated at lower temps and pressures then the other products the offer.
I read both of your posts and did not see where you may have taken the inlet to the Racor off and plumbed it into a bucket/container of fuel. I know I suggested this a while back and am confident you could at least narrow down the problem area if not find exactly what it is.
I would eliminate the inlet shut off valve as well and just take a hose directly from the Racor inlet to a bucket of diesel fuel. I bet your problem is near or in the tank because other than the shutoff valves this mod has been done over and over without any problems similar to yours.
Keep us posted as a lot of people are following this thread to see where it goes.
I read both of your posts and did not see where you may have taken the inlet to the Racor off and plumbed it into a bucket/container of fuel. I know I suggested this a while back and am confident you could at least narrow down the problem area if not find exactly what it is.
I would eliminate the inlet shut off valve as well and just take a hose directly from the Racor inlet to a bucket of diesel fuel. I bet your problem is near or in the tank because other than the shutoff valves this mod has been done over and over without any problems similar to yours.
Keep us posted as a lot of people are following this thread to see where it goes.
Sorry, I'm a little distracted, wondering if my life is about to fall apart.
Yes, I did the bucket test, when I emptied the tank. It seemed to help some, but there was still some air/foam at the inlet into the Racor. This was before I moved the o-ring and "sealed" the inlet valve stem. I am convinced that some of the air is definitely coming from the return/mixing chamber/abandoned factory pickup, but there is still something else going on. It is really frustrating, because, as you said, this unit has been used many times without problems.
I'm looking at a used FASS unit, which would eliminate the Racor entirely. But, its for a cummins, and would require some mods to work on this truck. I also just order a 140amp alternator from Quick Start ( my current one is only putting out 12.7v at idle, and a max of 13.4v), so money is flying out the door again, with very little coming in.
Does anybody know if the Racor is pressure rated, instead of suction, and for how much? I could retain the Racor, if I use it in conjunction with a home built air separator.
If I remember correctly, a FASS for Cummins is lower pressure than for a 7.3L.
You should be able to use it to feed your stock fuel pump.
Give FASS a call to be sure.
140 amp alternator? Is yours failing? Are you expecting to use more power? I don't know if that cable from the alternator charge stud is rated for 140 amps... that may need a visit.
Every added fitting on your fuel system is 2 opportunities for a leak (one in and one out). I have two elbows, the Racor, hose to pump, and hose to tank fitting. That's 8 opportunities for a leak outside the tank. There used to be 4 outside the tank - tank fitting, 3/8" to 5/16" reducer, and pump fitting. How many do you have?
You raise an interesting question on the Racor O-ring, I need to look at mine - but my fuel pressure has been good until I slosh the tank when low. I also have clear fuel in mine, without using valves.
You raise an interesting question on the Racor O-ring, I need to look at mine - but my fuel pressure has been good until I slosh the tank when low. I also have clear fuel in mine, without using valves.
I brought that up, Rich, based on a *similar* style on one of my tractors. If you don't lube your oring before trying to insert a bowl- or your orings aren't biodiesel certified (Viton usually) and swell, the can roll or get out of place when installing. I don't have this Racor on mine, so let us know what you determine?
If I remember correctly, a FASS for Cummins is lower pressure than for a 7.3L.
You should be able to use it to feed your stock fuel pump.
Give FASS a call to be sure.
Yes and no. I spent about 45 minutes on the phone with FASs. The rep was very helpful, even though she knew I had no intention of buying a new system.
The cummins system I was looking at is rated at 125gph at 45psi. This not enough pressure to feed a 7.3l directly, but it is way too much to feed the stock pump.
The current 7.3l system they sell is rated at 125gph at 55psi. They say this is designed to replace the stock pump, and feed the motor directly. Of course we know 55psi is marginal. They USED TO sell a 7.3l system that ran at about 10-12psi, and was intended to feed the stock pump. However, I was told that they had a large number of warranty claims, due to people not using it correctly, and using it as a main/only pump, which burned out the motors. So, they decided to protect themselves against all the idiots (my words, not theirs), and make the system work the way many people were improperly using them anyway.
Now, here's where it gets fun. I was told all I have to do is swap out the check ball and relief spring in the regulator, to bring down the pressure in the cummins system, to use to feed my Walbro lift pump. Cost is about $15. The systems have 1/2" ports all around. Reducing the outlet to the 5/16" inlet of the Walbro will raise the pressure, so I was advised that if I used a 8-10psi spring meant for a Duramax application, I would probably end up with close to 15psi.
While she didn't have an exact burst pressure available, I was advised that 30psi was the absolute safe max; although that much would make for a noisy pump. So,12-15psi should be a good number.
If I can get a good deal on a used system I'll go that way. If not, I can build a functional equivalent for under $200
Originally Posted by Tugly
140 amp alternator? Is yours failing? Are you expecting to use more power? I don't know if that cable from the alternator charge stud is rated for 140 amps... that may need a visit.
Yes, it is only putting out 12.7v at idle, and a max of 13.4. Also, starting with a cold engine (overnight), within only a minute or so of idling, the alternator is too hot to touch. The bearing is also noisy/rough.
I bought the 140amp from Quick Start because:
1.) It is a large case, vs the stock small case. Better cooling, bigger bearing.
2.) Heavy duty rectifier and regulator.
3.) Higher outtput at idle - approx 90-100 amp at idle vs. 60amp on a stock/stock replacement.
4.) All brand new American made parts.
5.) At $239, it was about the same price as Autozone/Advance chinese replacement.
I don't currently "need" higher amperage, but I plan to eventually add an electric engine fan, in place of the clutch fan. I did this on my Ranger, and idle voltage is an issue when the fan comes on, especially with headlights, wipers, and heater going. That fan draws about 45amps. This truck will need a bigger fan, which may draw even more.
Every added fitting on your fuel system is 2 opportunities for a leak (one in and one out). I have two elbows, the Racor, hose to pump, and hose to tank fitting. That's 8 opportunities for a leak outside the tank. There used to be 4 outside the tank - tank fitting, 3/8" to 5/16" reducer, and pump fitting. How many do you have?
I count 9 total, including npt fittings and hose clamped connections. I may try removing the inlet valve, but I thought they were commonly used to allow changing the filter without making a mess?
You raise an interesting question on the Racor O-ring, I need to look at mine - but my fuel pressure has been good until I slosh the tank when low. I also have clear fuel in mine, without using valves.
Electric fans? Watch out! The stock fan is far more powerful than any electric fan that can fit in there. I've towed up a steep hill on a 105-degree day at 45 MPH and that fan was busting its... er... blades to keep the temp in range. The Ranger is a runt cousin with allergies and toe fungus when compared to a Superduty with a 7.3L.
Wouldn't it make sense to just FIX the air coming into the system first?
You probably only have 15 ft of fuel line and "stuff" to worry about.
Even moreso, if you are using the FASS to bandaid the air in fuel issue, what happens if/when the problem gets worse later?
About the RTV...Permatex's website lists the blue and black as their silicon based RTVs. Their FAQ specifically mentions their silicon based RTVs as being not suitable for fuels.
And your teflon sealant...make sure it is suitable for diesel. Typically, if it does not SPECIFICALLY say it is, then it isn't. I should have stated this more clearly. Usually when someone says "teflon sealant" they mean the white stuff for water pipes. Gasoila specifically says it is good for gasoline and diesel, which is why I suggested it
But that's all up to you. We're just here to share info. At the end of the day, it's your rig, do what suits you
If it were me, I'd dig into the Racor, the tank, and the lines until I figured out what problem was. You definitely should NOT be getting air in there
09-21-2015, 10:02 PM
) I got a huge amount of plastic shavings, and they kept plugging the little 1/8" drain hole in the bottom of the sump. 
