Bypass filtering of diesel fuel

[STEVEBROOKS]

I'm considering adding a fuel bypass filtering system on my truck, whereby the fuel would be pumped from the tanks, finely filtered, and then passed back into the tanks. My thought is that by doing so, the engine feed line filters would both last longer and have less pumping restriction. Has anybody added a system like this on their truck? If so, what brand or individual components did you use?

Thanks,

Steve

 

[Wingate]

couldnt you just install a set of 2 micron filters under the truck plumbed in parallel?

 

[cerberusiam]

No reason to really do it as it is a natural by-product of the stock system. Under most ciurcumstances 70% of the fuel delivered to the CP-3 is routed back to the tank anyway. Just add adequate filtration to the stock system.

Adding a FASS\AD accomplishes the same thing in conjunction the stock system. As long as the pump is running it is polishing the fuel as it also generates much more flow than the engine uses and it routed back to the tank by the pressure regulator.

Using multi-stage filtration is a much better solution for efficacy and operation.

 

[JRBurton]

Put a FASS on it with the duel filters and do away with stock filtration. You will be much happier in the long run.

John

 

[BLNRAY]

Like he said put a FASS on it .

 

[STEVEBROOKS]

Update on my original post: have decided to go ahead with a fully separate fuel by-pass filtering system. Have a pretty good design for this system worked up, and it will involve a sump being added to the main tank. Would like to hear about any positive/negative feedback and installation advice from anybody who has added a sump like this http://www.glacierdieselpower.com/product.aspx?pf_id=STK5500BO or something similar.

Thanks in advance for the replies!

Steve

 

[Bob4x4]

Did your plan come from the marine industry where fuel polishing is done?

 

[STEVEBROOKS]

BOB4X4,

Yes, partly, and also fro input from Todd at TC Diesel. Main consideration is the extremely tight tolerances in our CR injectors and long-term effect of water/micro-abrasives in our fuel on them. Granted, x % of fuel that reaches the common rail is returned to the tank(s) and runs through the filter(s) again, but that also means x % only gets filtered one time. I've had an additional filter on my truck, between the stock canister and the CP3, for years, but still had to replace my original injectors at 145,000 miles. I've been told that's actually not too bad of a number of miles to have reached before replacing them, but I'm shooting for much better in the future after my by-pass system is installed.

Per my post above, would still like to hear from anybody who's installed a sump in their main tank.

Steve

 

[6speed]

I have been running a FASS 150 for about 7 years and 150K in mileage. 240K on the truck now and original injectors. I probably just shot myself in the foot bringing up how many miles I have on the injectors. I am anal about my fuel. NO BIO in this system.

 

[Tuesdak]

BOB4X4,

Yes, partly, and also fro input from Todd at TC Diesel. Main consideration is the extremely tight tolerances in our CR injectors and long-term effect of water/micro-abrasives in our fuel on them. Granted, x % of fuel that reaches the common rail is returned to the tank(s) and runs through the filter(s) again, but that also means x % only gets filtered one time. I've had an additional filter on my truck, between the stock canister and the CP3, for years, but still had to replace my original injectors at 145,000 miles. I've been told that's actually not too bad of a number of miles to have reached before replacing them, but I'm shooting for much better in the future after my by-pass system is installed.

Per my post above, would still like to hear from anybody who's installed a sump in their main tank.

Steve

The fuel that only gets filtered once IS the bigger concern. For the filtered once then burned fuel your main filters need to be the best because if it gets by the main filters it can hit the injectors. You can have all the bypass filtration in the world and have a failing fuel transfer pump drop debris into system or catch dirt/water/wet fuel from a fill up that the bypass doesn't have a chance to filter. Worse is water in the system esp with the new hygroscopic ULSD and Biodiesel. Add bugs and you can quickly in a single tankful ruin the complete fuel system from the fuel tank to the injectors. My experience has a water separator alone saving a fuel system when side by side the other truck lost the IP and injectors due to bad fuel.

If the main filter/water separator doesn't catch it it can hit the injectors. Thus the effort and money is best spent on the main filters and a separate water separator that also does a lot of bypass filtering. (Bypass filtering the main filters do is a side effect of the main function of purging air and cooling.) Other money should be spent on lube and biocide.

IMO your old system with only a "additional filter" isn't enough as a dedicated water separator 'filter can' is needed. The factory and combo filter water separators have a reputation for not doing very well with water.

The ideal system is a heated water separator on the suction side of a pump. Both heat and suction improve the performance of the water separator. The heat also solves gelling in cold weather at the first filter. Then lift pump and last the fine filter. This catches everything it can before that % of first/single pass fuel hits the injectors.

Nothing filters debris from the CP3 wear before the tubes/injectors have to deal with it.

 

[cerberusiam]

The injector failure probably has more to do with the 12 years, driving style, fuel quality, and the injector short comings than the 145k. The time and miles is probably not that bad for that year. You don't say what filter you had between the OE and CP-3 so no telling if you did yourself any favors there. A lot of filters are not much better, if any, than stock so you don't gain much.

A bypass system in the main tank just does not gain you much unless you are going to fill it then park it until the system has a chance to completely filter the whole tank. Once you fill and start driving you will still pull any contaminants thru the fuel system long before a bypass system can clean them out. Since the stock system does all that you are much further ahead building the filtration into the stock fuel path. The only way a bypass system works is if you fill a separate tank first then pump it into the main tank. That would a worthwhile endeavor rather than a bypass system.

Since the bypass system on the main tank doesn't work the sump is a useless additon and all it does is ruin the tank. You don't want main line fuel out of the sump so it would only be a circulation that is not that effective anyway thne you have a ruined tank when it doesn't work.

The most effective solution is a FASS with a 10 um solids filter and the best WS you can get and a fuel heater., then thru the OE filter wit the best filter, and then thru a 3 um final filter before the CP-3. Al the crud gets pulled out before it gets into the main fuel system and the existing fuel gets polished as you drive.

You still have to be aware that putting good fuel into the tank is key. You cannot run crud thru the tank and expext the system to last forever, no matter how good a filtration system you have.

 

[STEVEBROOKS]

All good points above, and are why I've designed the system like I have. I currently have two separate tanks (stock and bed) with their own pumps, that I'm able to electronically switch between. I'll be adding two more electric switching valves, another separate pump, and a filter head (with a filter restriction gauge installed) for a Zinga AE-03AZL 3-micron Aqua-Zorb filter, along of course with all the needed fuel line connections. The bed tank's drain will become its feed location for the by-pass circuit due to it being the lowest location in the tank, and the sump added to the stock tank will do/be the same for it. In addition, I'll install manual ball valves to block off any tank I need to, and in case either/both of the tank pumps fail I'll be able to run the engine off the separate pump itself. After system installation, I'll run off one of the tanks for its approx. 700 mile range while the other tank has been in continuous filter by-pass mode for that length of time. That tank's fuel should by then be fully finely filtered and any emulsified water removed too, then I'll switch tanks and do the same again. After that, I'll always keep one tank fully filtered and fill up the other tank as needed and filter it.

I hope this explains better what I'm aiming for, and I'll post more info after completion.

Steve

 

[cerberusiam]

Yep, that makes sense. Still think it is excessive work and cost for return, but, it is your call not mine. Hope it meets expectations.

 

[AH64ID]

There is no need for fuel bypass filtration on a single tank setup, as mentioned most the fuel gets filtered at least twice before going thru the injectors.

An additional f/w sep and a 3um filter are the best way to go.

FASS is a good way to go, just make sure you have the updated one with the proper filters or your filtration could be worse than stock... for those that have had FASS for a LONG time better check your filter numbers as many of the systems on the road don't improve filtration.

If you are truly intent on going to the next level the setup similar SJBrooks has is the way to go. Only fill the bed tank and use a water absorbing filter, no need to go 3um on the tank-tank filtration just remove ALL the water. Use the lift pump to push fuel thru a 3um filter after the OE canister/heater.

If you need the full range of both tanks you fill the bed tank and pump into the main tank at the fill station.

If money were no object I would put a small bed tank in and do just that, but like cerberusiam I am not sure it's worth it in the long run.

 

[RDeFayette]

The problem I see with the 2 tank set-up is when you "think" you have removed all the water you still have condensation to deal with where as water is re-introduced into the fuel. Just my 0.02
bypass filtering of oil systems works because the oil system is "closed" (other than the addition of a quart of oil every once in a while). Fuel systems are open, additional fuel added every 400-700 miles. (depends on how many tanks you have and if you believe some of the outrageous mpg numbers posted). IMO, If ultra-fine filtering is the desired end result just add additional inline filtration to get to the filter point you want as an end result. Fuel going in is filtered as you want + the returned fuel is then "bypass" filtered. just an opinion. from the K.I.S.S. generation. BTW, 200k miles and counting on the original injectors with an AD 100 on this truck for the last 100k miles. low$$ fuel at a low volume dealer will kill injectors. I have yet to replace stock injectors on any mine, my dads or my brothers HPCR trucks. Only time we ever changed any of them was to go bigger.

 

[AH64ID]

Condensation in fuel is typically easier to filter out as it doesn't get nearly as emulsified as water than ran thru the fill station pump.

 

[RDeFayette]

Condensation in fuel is typically easier to filter out as it doesn't get nearly as emulsified as water than ran thru the fill station pump.

True, but water is water and with 2 tanks he's under the impression/assumption that once the water is filtered out and the by-passed fuel is in the 2nd/"good" tank that it no longer is an issue. It may not be emulsified/"blended" into the fuel anymore if it's "just" condensation but sooner or later it'll get picked up by the pump. All the gyrations of building a by-pass filter set-up to remove the water and then have it "mysteriously" reappear is an exercise in futility. Only point I was trying to make.

 

[AH64ID]

True, but water is water and with 2 tanks he's under the impression/assumption that once the water filtered out and the by-passed fuel is in the 2nd/"good" tank that it no longer is an issue. It may not be emulsified/"blended" into the fuel anymore if it's "just" condensation but sooner or later it'll get picked up by the pump. Only point I was trying to make.

Yeah you still have to have f/w separation on the feed line, but you can get all of the really emulsified stuff out with a water absorbing filter between both tanks.

 

[RDeFayette]

Yeah you still have to have f/w separation on the feed line, but you can get all of the really emulsified stuff out with a water absorbing filter between both tanks.

agreed, but as I said a couple posts back just skip the 2nd tank put the filters in line and run it straight to the CP3. Water gone, dirt gone, cleanest fuel on the face of the Earth. Why go through all the filtering gyration just to stick the clean fuel in a "holding" tank. No reason to not use it immediately then have the remaining "super pure" fuel returned to the tank, eh? Same results as far the CP3 and injectors are concerned. less plumbing/less $$$(extra tank)

 

[AH64ID]

The biggest intent isn't to put the cleanest fuel into the holding tank, it's to fill the bed tank and filter it with a water absorbing filter as it fills the main tank. A water absorbing filter will stop all fuel flow when it is full of water, this is why you don't want it on the fuel line to the truck as it would cause your engine to die.

The fuel will be drier than just the filters on the AD or FASS.


Speaking of cleanest fuel on the planet, which filters are on your AD100? The original filters where worse than the OEM one.