The Diesel Stop banner

External fuel filter/water separator

7K views 71 replies 6 participants last post by  clev 
#1 · (Edited)
Thought that I would start a new thread, in addition to E350Van's. He posted a great thread, but I'm starting from scratch and will probably have a few different questions. And I KNOW that I'll have a lot more problems than him, LOL.

He recommended a Stanadyne FM100 but I can't find that anywhere on the web. What I did find was PureFlow AirDog A4SPBF168 which retails for ~$600. I found it at one on line store for $547, delivered, and no hassle returns. It comes with all fittings that looks pretty simple for follow up of the Hutch mod on the fuel tank.

Can anyone recommend a better, less expensive system?
 
#2 ·
Well, I ordered the Air Dog. I called tech support and the kit is made for the 99-2003 7.3 diesel, 'F' 350. The fuel tanks and pumps should be the same; could someone comment on this? This is basically installed between the tank and the frame mounted pump, and has a return line to the tank filler neck.

The web site that had the Dog, had a clock counting down through 11 hours; it was a limited time sale. So at about ~$50 savings from other sites, I jumped on it. Anyway, appreciate any advice.
 
#3 ·
#4 ·
Thanks bork; too late, done and ordered. Any additional advice that you can give would be appreciated. I'll be dropping the tank, so I'm interested in any problems with detaching hoses and wiring on the top. I have a universal set of Ford AC/Fuel Line disconnects; 1/4" - 1/2". If you've done the Hutch mod, did you use copper or steel tubing?
 
#5 · (Edited)
Clev, the FM100 is just a filter head and filter (and exactly the same as the re-branded NAPA part # FIL 4911 that I included in the thread. I did purchase mine from theDieselStore because they are a site sponsor and they carry optional Stanadyne Fuel Manager accessories that can be added onto the filter head, like a 100 micron(rock catcher pre-screen, fuel heater, clear water bowl, etc.) My total for that was around $130 including tax! The Napa part is just the head and one 5 micron filter/water separator for around $50! The AirDog is a filter combined with a fuel pump and is similar to a Fass system because they are father/son. Unless you are going with some kind of big fuel (500+ hp) system on your van, it is kind of a waste of money. The factory Bosch pump puts out plenty of flow even for 160/30 single shot injectors. The AirDog is apparently good, but pricey because it integrates the filter/pump/air separation. Problem is if it ever dies far from home, what are you going to do while you wait for the replacement? If the factory pump dies, I can put in another quickly on the side of the highway! The Dahl filter that Bork mentioned is a top notch filter that I've used on F-Series Diesels in the past. The only reason I didn't go with it on my van is the size, which is around 13" tall. Anything hanging far down below the frame rail or trans. crossmember is susceptible to getting beheaded by highway debris.
 
#6 ·
The AD still uses the factory fuel pump. I downloaded the installation manual and it described the procedure of disconnecting the incoming fuel line and attaching the AD fuel line. All hoses and fittings were included. Too late anyway, already ordered, and charged.

Glad you responded to this thread. With all the mechanic work that I've done, I've never bent, shaped, nor flared any kind of tubing and know nothing about the kinds, sizes, or connections. I know that I have to fabricate 2 pieces for the Hutch mod; pick up foot and the long bent piece to get away from the float. What size tubing does that take? And, will any bender suffice? I've been looking at one on Amazon for ~$24 delivered. Can I cut with a hack saw or should I use a specific tube cutter? Do I need flaring tools or do the nuts and ferrels collapse to seal? Sorry for all the questions, but I like to have everything ready when I start. LOL!! Even than I always have a lot of trouble. Thanks, Stock; I appreciate your help.
 
#7 ·
Yup, it does hang down a bit.. the tubing I used is stainless steel also. IIRC I purchased at a hardware store, off the little display rack that has foot long stock of brass, aluminum, & SS, bars, tube channels, flat stock etc... for projects. (also inexpensive) I thin k it was in the #9100 set . 3/8" SS tubing? Retail Merchandisers - K & S Precision Metals: Full Line Metal Specialists
 
#8 ·
If you you the compression fittings, put some grease on the ferral & nut, when on the tube, before assembling. then tighten up. Reason is, brass on brass binds, & will help the ferrals seat, so it doesn't leak. I wasn't too crazy about using brass for the coupling, but that's all that was readily available. I wish I would have used a longer piece to slide into foot, like I saw in video, to eliminate problems with the little side check valve. I think mine fell out presently & suck air now when tank is just below 1/4 tank. I have a Spectra tank waiting in my shed now, so I will do all at once.
 
#9 ·
Clev, just trying to help you avoid a dilemma, so if I were you, I would make a cardboard template that is the same size as whatever you are going with. That's what I did to help me see how all would be plumbed in. Ground clearance was one concern for me that might not be important to others, but you also need room ahead of and behind the filter for gradual bends in the fuel lines. Each 90 added to any plumbing is about equal resistance to another foot of line, so you want to try for all straight fittings. I don't know where you will mount the AirDog but I've seen some mounted outside the frame rail. I guess that's O.K. So long as you never get T-boned on the driver's side. Either way, I highly recommend crawling under there to plan for the limited space first. Hope this helps. Cheers!
 
#10 · (Edited)
Hey, Stock. I just noticed that you are in College Station and that's only about 130 miles from San Marcos. I'm an early riser; how about you? I was thinking that if your were to get up about 5:00 AM and head this way, you could probably be here by 8:00. If you decided to do that, my wife could have a good Texas breakfast ready; eggs to order, sausage or/and bacon, hash browns, gravy, and biscuits. We could get started on my van about 9:00 and between the two of us, probably be done by 3~4:00, at which point I'd give you $200. And if you wanted to stay for dinner, I'd fix you a good steak and shrimp dinner with a good bottle of wine. You think that you might be interested in this about the end of April?

OBTW; I am retired, so Saturday's and Sunday's work for me.
 
#12 ·
Hey, Stock. I just noticed that you are in College Station and that's only about 130 miles from San Marcos. I'm an early riser; how about you? I was thinking that if your were to get up about 5:00 AM and head this way, you could probably be here by 8:00. If you decided to do that, my wife could have a good Texas breakfast ready; eggs to order, sausage or/and bacon, hash browns, gravy, and biscuits. We could get started on my van about 9:00 and between the two of us, probably be done by 3~4:00, at which point I'd give you $200. And if you wanted to stay for dinner, I'd fix you a good steak and shrimp dinner with a good bottle of wine. You think that you might be interested in this about the middle of April?

OBTW; I am retired, so Saturday's and Sunday's work for me.
Heck we all may come! biscuits & gravy , steak, $ ! It doesn't get much better than that!
 
#11 ·
Good grief; I just re-read my last post post and that reads more like a date than a work deal. Really guys, I'm not that way! I'm U.S. Army Special Forces (Green Berets), Retired.
 
#13 ·
Was that a yes?
 
#14 ·
Quote:
Originally Posted by clev View Post
Hey, Stock. I just noticed that you are in College Station and that's only about 130 miles from San Marcos. I'm an early riser; how about you? I was thinking that if your were to get up about 5:00 AM and head this way, you could probably be here by 8:00. If you decided to do that, my wife could have a good Texas breakfast ready; eggs to order, sausage or/and bacon, hash browns, gravy, and biscuits. We could get started on my van about 9:00 and between the two of us, probably be done by 3~4:00, at which point I'd give you $200. And if you wanted to stay for dinner, I'd fix you a good steak and shrimp dinner with a good bottle of wine. You think that you might be interested in this about the middle of April?

OBTW; I am retired, so Saturday's and Sunday's work for me.
Bork: Heck we all may come! biscuits & gravy , steak, $ ! It doesn't get much better than that!

Bork, somebody must have told Clev I was food motivated! :) When you re-work your in tank assembly, carefully measure the difference in depth of the 2 tanks. My new Spectra tank was about 1" deeper than the factory tank where the fuel sending unit is located. You will also need to transfer over all the plastic caps and rubber tank strap pads from the old tank. I put a layer of self adhesive foil faced rubber adhesive window and door weather stripping on all the parts of the top of the tank that contact the underside of the body. I didn't want metal to metal contact and the 2 factory plastic rub pads were not enough. My Spectra tank did not require any Harpoon mod either, it has short metal fill and vent tubes. I think it is really @ 38-39 gallons! The spectra does have sort of a baffle in front of the tank so I put a gradual Z bend in my aluminum return line to make it go over that baffle. Most importantly, remember that the 6" hole cut out in the Specra tank is even more razor sharp than the factory tank hole. My new filter's first job was to remove blood from the fuel!

Clev, I think Bork might load up all of us van guys from Florida to Texas! You can haul a football team in a 7.3 van! Haha! Sure sounds good though! Not sure when you're wanting to do it but lately I've only been using my van for very short trips. I've been worried about my ball joints and front brakes. I am about to rebuild the whole front end and continue to bullet proof the whole van this spring! All the ball joints, wheel bearings, seals, brake pads, jounce springs, shocks, and Ford Ambulance steering stabilizer parts have been sitting here for a week while I researched what coil springs to get. I can do make new threads with pics if anyone needs info on any of the above. Yesterday, I put on my bellowed up pipes (triple wrapped and taped as well as down pipe?)! front receiver hitch, and rear RV shocks. Heavy duty coils should be here Wednesday, but we'll see! We have my wife's car but that's been tied up lately with our boys' sports. If I can get over there to help you, I will do it though!

Here's what has me a little confused. I can't for the life of me, figure out what AirDog is costing you $600 unless it has an integrated fuel pump (which you don't need). I believe Air Dog uses some patents that belong to Stanadyne for air reduction. Sure, they may put their own twist on it and a heavy marketing campaign, but the designs are nearly identical to $50-$60 Stanadyne FM 100 reverse flow filter heads, and Stanadyne has been making filters even with integrated fuel pumps, heaters, etc. for a long time. The other thing I am wondering is how big is it and how does it mount? I am asking that question because it took me longer to figure out filter sizes, make the bracket, and gather th parts than the whole tank/filter install took. I had an easy install with nice sweeping gradual bends in my fuel lines because I planned it all out to work in that space. I have read all of the famous Cackle threads since Hutchinaugusta first solved the air in fuel lines problem right here on this site. It's not that I want to tell you what to buy, but I'd rather see you get 100 more HP for that kind of money. Your van has one frame rail mounted factory (Bosch) fuel pump on it now, right? These pumps are pretty awesome. So that pump puts out way more flow than your van would ever use even with 100 race tunes and single shot injectors.
What is inside your tank is a crappy factory white plastic pick up cartridge filter with two little cylindrical screens in it about the diameter of a pencil. I put a photo of mine in my filter bracket post which were clogged with the infamous silver lining! Like Bork mentioned, I cut a piece of 3/8" o.d. stainless (about 4-5 inches long). I found a stainless tire gauge in my garage that was about 6" long and 3/8" diameter that I cut to length and connected with a 3/8" to 3/8" brass compression Union. The reason was all of the commercially available tubing had thick walls which decrease the inside diameter (and fuel flow). For the return piece, I bought an air blow gun with an 18" extended tip from Harbor Freight ($12) because it was 5/16" o.d. aluminum tubing which bends easily. I used a 3/8" drill bit to deepen the hole in the new plastic Ford pick-up foot all the way past the by pass valve and then slipped the pick up foot with 2 - 3/8" hose clamps on it over the stainless piece. The length of that piece of stainless is determined by taking a measurement of the tank depth and deciding how close you want the pick up foot to the bottom of the tank. Don't forget to calculate ALL of the parts in your length measurement, including the pickup foot clamped to the stainless, the extra 3/4-1" for the compression fitting, and the factory sending unit. The foot has a flexible bellows on it so I put mine right near the bottom. Even if it is touching the tank bottom it can still pick up more fuel than a 3/8" hose can handle because it has little spacer feet all the way around the bottom. The goal with the return is to simply direct returning fuel and air bubbles away from both the foot as well as the fuel level float, so it is actually better to bend that line towards the front of the vehicle. The only trick there is getting that newly made assembly and the float back into the tank without damaging the float. The other problem that Hutch mod eliminates is the crappy fuel supply lines with a/c type fittings. The return line really doesn't matter because these fittings suck in air only when they are under suction. That means only the fuel supply line from the tank to the pump which will be your 8' piece of 3/8" fuel injection hose (@$25 at the auto parts store). Any fuel filter can be put between the tank and pump. The factory filters are around 5 microns depending on brand. The reason I buy 2 and 5 micron cartridges is that I don't ever need to change the factory filter often in my van! I use 2 micron most of the year and 5 if I'll be driving in freezing temps.
After sending unit is installed in tank, next order of business is to connect new supply hose to top of tank with double hose clamps. Then raise tank to where you can still get your arm up above tank. Plug in fuel gauge wires, connect return line, check your fill vent hoses, and make sure your fuel injection hose is routed where you want it running over towards frame rail. Now raise the tank with a 1 gallon paint can on top of your floor jack and tighten the strap nuts. Plumb into your filter using two 3/8" hose barb fittings with thread sealant rated for bio-diesel. Run hose from top of fuel tank along frame rail, and zip tie it or secure it wherever possible. Cut it to length where it will go over barb fitting on filter inlet. Slide 2 clamps over hose facing opposite directions and slip hose onto barbed fitting and tighten clamps. Take the loose remaining piece of 3/8" hose that you just cut and heat one end with a heat gun or dip into boiling water. Slide that end over the inlet of your fuel pump. You can work it over the ridge as long as it is hot. Clamp it and then cut other end to length and double clamp to the 3/8 barbed fitting on fuel pump outlet. Reconnect all fuel filler/vent hoses, and add 5 gallons of fuel. Cycle the key to on several times without starting engine. This is a good time to check for leaks between key on cycles. Then start her up and enjoy the smooth sound!
 
#15 ·
Wow! What a great, informative write up; I couldn't ask for better instructions. Thanks, Stock. I have to go to Virginia next week and won't back until the last week of April. I'll gather the rest of my parts and be ready to tackle it then. My offer for your help still stands; think about it.

Here's the link for the installation manual for the AD; it lists all parts.

http://www.pureflowairdog.com/manuals/A4SPBF168.pdf

It's a complete kit with brackets, hoses, and Ford quick connect hardware for plug and play.
 
#16 ·
Quote:
I'd rather see you get 100 more HP for that kind of money
Unquote

I, honestly, cannot use anymore horsepower. I have a DP tuner set in economy mode, and when I romp on it, it climbs thru 1200 on the EGT gauge very rapidly. From a dead stop, I can get 70 MPH, and 1200~1400 degrees on the EGT gauge in about 7~8 seconds. If I drive it hard for 3 - 4 minutes, backing off the accelerator and then romping it again, the Check Engine light comes on, and stays on for about 5 minutes; until it cools down. I've always had to watch the EGT's and try to keep them below 1200, but it's been more critical since the tuner. As long as I accelerate normally, either towing or solo, or kick in the passing gear just for passing, just 'sane' driving, egt's have not been a problem. But, I really have more power than I can safely use.
 
#17 ·
Whoa buddy, I hope you keep at least two wheels on the ground! I know you Special Forces guys aren't afraid of wide open throttle! Not sure why my brain went straight to, "What else can we do to drop EGTs so you can lay into it worry free?" By the way, thanks a million for your service to this great nation. I am grateful. I have been working a-lot but when I get a chance, I'm planning on looking at those AirDog specs you provided in the link. Sometime soon I'll be getting rid of my EBPV pedestal and maybe a thread on how I'm going to convert my exhaust adapter to high flow for less than $5! Safe travels!
 
#18 ·
Your welcome for my service; it was the best 20 years of my life. Now that I'm disabled, I look back on some of the missions with longing memories. Anyway, the AD looks like a great kit and it's being delivered tomorrow. $547 with 2-day delivery.
 
#19 ·
Without the proper tool, what can I use to unscrew the band on top oft he fuel tank?
 
#20 ·
The only specialty tool the job requires is the 3/8" & 5/16" fuel line disconnects. It is nice to have a 15mm ratcheting wrench for the tank strap nuts but a regular wrench will do it. Just takes a little longer. Not sure what band you mean though.
 
#21 ·
Good morning, Stock.
I thought that there was a large 'band' screwed on top of the lift assembly. I saw it on one video and the guy was using a ratcheting strap, trying to unscrew it.
 
#22 ·
The top of the factory sending unit is basically like a 6" round upside down pie pan. There are about 6-8 sheet metal bolts (I think 8mm, not sure) holding it down. After you remove them, you can carefully work around the gasket with a putty knife or razor scraper to remove the gasket. My new tank came with a new gasket, but I could have re-used the original. Comes off real easy. One thing I forgot to mention earlier, when you drop the tank is a great time to modify your filler hose neck to accept truck stop (bigger) diesel pump nozzles. Use the "search" function on the 1999+ 7.3 upgrades and aftermarket forum. There's plenty of info on this mod and it is easy with filler and vent unit already removed. That way, if you're towing a trailer, you don't have to compete in the mini-van rodeo to fuel up!
 
  • Like
Reactions: bork
#23 ·
Clev, I finally got around to reading the specs on your AirDog. That is an impressive little unit. I really like how they got all of those functions in a compact space. Trust me, it is critical for the space in the vans. I also should apologize for not reading your Signature or not knowing how souped up you already have your van. I know you will be amazed at the disappearance of the cackle after all your fuel mods are complete! The way the Air Dog is plumbed should make the install extremely easy too. Just upgrading my fuel system had me grinning every time I started mine up, so you should have a perma grin after this all comes together! Next, you'll be asking Santa for a regular (#'s 1-7) injector to replace that long shot (#8) the factory used to sort of address the air in the end of the rail! ?
 
#24 ·
Good morning. Yes, It is an impressive unit, and the quick connects will be easy. I'm looking forward to getting started on it. I've got someone locally to give me a hand with the tank, so everything should go smoothly.
 
#25 ·
OK guys and gals; getting ready to tackle this job in a few days. I've never owned, nor used, a tubing flare kit or bender. I'm looking at them on Amazon in molded cases as a complete flare kit. But there are so many, and me being ignorant of what a good quality kit is, I don't know what to buy. Most specifically state 'not for stainless steel' and that's what I need for the fuel tank. I want a good kit for future use on transmission and fuel lines, so, can someone offer a recommendation on what I should buy? Or better yet, if you have a free minute, go on Amazon, take a look at their inventory, and give me a recommendation. I have Amazon Prime, so I can have the kit by Wednesday. I also need a bender.
 
#26 ·
All stainless steel I've seen is tough & I doubt a flair tool would work, unless it is special soft ? stainless steel. Copper & brake lines are soft & thus workable. I imagine Snap-on would be the Cadillac of tools?
 
#27 ·
Thanks Bork. So, how do you flare the SS tube that's used in the hutch mod?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top