The Getaway...Crom's build and adventures

Just can't get better than this build.

 

I am now thinking about taking on this OBA project with my Viair 450.

 

Thanks so much!

Go for it! Once mounted, it saves a ton of time. I aired up my wife's car tires 4 PSI in (4) seconds. lol

I'm going to list some of the parts and prices that I used in the project, it may be useful...

 

Nice work on the OBA!

 

I used 3/8" Flexzilla air hose to go from the compressor to the back of the truck.

Cost was negligible between the two size choices.

1/4" left vs 3/8" right.


The connectors are both 1/4" NPT. Won't that slow down the 3/8" air hose?


Not a chance. I don't fully understand the NPT sizing circus, but if you look inside the connectors, the air passage way is substantially larger for 3/8. Furthermore if you do the old-school-huff-and-puff test, there is a lot more resistance blowing through 25' of 1/4" hose vs. 3/8".


I have no plans to ever run a tank, but if I did, 3/8" would be mandatory in my book. Anyways, I used 3/8" hose in my project for running along the frame rail.

For airing up the tires, I use the 1/4" sized hose since it does the job and it's lightweight.

 

This is a picture of my initial test connection.


I like this brand air hose, but I wasn't about to be showing lime green anywhere on the truck, so I wrapped about 24" of air hose end with dry vinyl tape, finished the ends with regular automotive electrical vinyl tape.

The end of the air hose pictured below is the one that connects to the quick disconnect fitting on the back of the cab.

All you see is a black hose if you look at the truck.


Hose runs between composite bed and frame, then tucks into the frame rails and through cross members to the rear of the truck, then it sweeps 90° above the factory hitch all the way to the passenger side where it's secured with velcro or zip tie.

I connected it to the passenger side, so when I get aftermarket bumper, reconfiguring the air hose is an easy task. Plus I like exhaust.

To mount the final quick disconnect and finish the hose, like many before me, I drilled a 1/2" hole in the tow hitch.

I cut the hose to length, recovered the air fitting from the excess hose. Then grabbed some 1/2" stainless washers. I spray painted the fresh hole I drilled.



Then assembled.



Used size 4 stainless worm clamp with red lock tight in the screw.


I found these rubber chair ends to protect the air disconnect.


Finished end, ready for business.


No air leaks, tested to 150 PSI.

 

Nominated for Best Documented Build Thread.
I could watch this unfold on a TV show.

 

On the electrical side, the air compressor is completely controlled by a $0.25 switch I had, plus a $15 80-Amp relay I bought. By design I only wanted my air compressor to run if the truck is running, which is why I tapped the ignition circuit for +12v.

Ignition circuit to tap is under the hood fuse block.





Here it is mounted in the engine bay. I took advantage of a factory hole in the engine room wall, it was M8 1.25.

Hole is on the bottom of relay, top is held on by 3M super strength molding tape.


(no picture) I wrapped the 5/16" exposed lugs with dry vinyl tape to protect them, and then covered that with 1/2" split loom held on by zip tie. It looks stupid, hence no pic, but it's very effective! lol

I used a Bussman circuit breaker to protect wiring.


And unfortunately, the top nut on my factory positive battery terminal clamp is so tight, that it spins the captured bolt below, so I had to piggy back onto the terminal bolt to finish this project. I'm now going to have to shop for a replacement.

For the relay control, I tapped a wire which was a tap to another. It gets +12 via the green ignition wire. (also pictured above)



Easy to sneak wire up into the fuse box by following the main factory wiring.


Finished end that provides +12v, attaches to relay. Only hot when truck is running.


Finished ground wire, connected to switch inside cab, and relay control.


Switch harness. When switch is closed, it grounds the relay and current will flow to the compressor. Stupid simple--just the way I wanted it.



Final location of switch on the left for compressor switch, and all my other mod switches.

 

This is about how I feel right now.

 

Nice. I've been wondering how folks protect the internals of a quick-disconnect fitting from filth exposure under the truck. I love it when I find random crap at Home Depot that works perfectly.

 

The major difference with NPT is that the thread is tapered.

 

I just told the wife that I will be starting a new project...ooops! If looks could kill.
Thanks for the parts list and other stuff. It will be useful.
I was curious where the line would terminate. Now I see.
Thanks for sharing all your hard work. I wish I could be so detailed.

 

OBA Parts List, for hard mounting the compressor.

Air / mount side:

• $29 Viair 92804 18" Stainless Steel Braided Leader Hose without Check Valve
  Viair 92804 18" Stainless Steel Braided Leader Hose without Check Valve $13.95
• $12 Milton S-764 1/4" FNPT HIGHFLOWPRO V-Style/European Interchange Air Coupler Fitting (High Volume Low Pressure Application)
  Milton Industries Inc. S-764 HI-Flo V-Style' A,M,V-Feet 1/4-Inch Brass Body x (2) $6.90
• $8 Milton Industries S-761 1/4" FNPT HIGHFLOWPRO V-Style/European Interchange Brass Air Plug Fitting (High Volume Low Pressure Application), Pack of 2
  Milton Industries Inc. S-761 HI-Flo V-Style 1/4-Inch FNPT Brass Plug 2 Per Card $6.91
  
• $23 Flexzilla Air Hose, 3/8 in. x 25 ft., 1/4 in. MNPT Fittings, Heavy Duty, Lightweight, Hybrid, ZillaGreen - HFZ3825YW2
  Legacy Manufacturing HFZ3825YW2 Flexzilla 3/8" x 25' Zillagreen Air Hose with 1/4" MNPT Ends and Bend Restrictors $20.87
• Street Elbow, 90 Deg, Brass, 1/4 In., NPT VS1202P-4-4 $7.46
• Quantity (10) - 1/2" Stainless washers from Home Depot ~ $5.00
• About $20 worth of class 10.9 M6 1.0 Bolts from Autozone. - $20.00
• Huangwu Sobrilli 3.5mm Earphone Adaptor for Phone Xs/Xs Max/XR/ 8/8 Plus/X (10) / 7/7 Plus, Audio Splitter Accessories Music Aux Adapter
  Aluminum Sheet Plate 1/8" (.125) X 9" X 12" 9X12 New Remnant $9.99
• 3M Super strength molding tape from walmart $5
• 7/8" rubber chair ends, walmart $2.00

Electrical side:

• $63 EWCS 4 Gauge Premium Extra Flexible Welding Cable 600 Volt - Black - 25 Feet - Made in the USA
  4 AWG Premium Extra Flexible Welding Cable 600 VOLT - BLACK - 25 FEET - EWCS Branded - Made in the USA! $26.90
• $13 Panduit SCSS4-L Code Conductor Butt Splice, Short Barrel, #4 AWG Copper Conductor Size, Gray Color Code, 7/16" Wire Strip Length, 0.38" OD, 1.00" Length
  Panduit SCSS4-L Code Conductor Butt Splice, Short Barrel, #4 AWG Copper Conductor Size, Gray Color Code, 7/16" Wire Strip Length, 0.38" OD, 1.00" Length $7.88
  
• $17 TEMCo 25 Pack Bare Copper Welding Battery Cable Ends, Lugs Terminal 4 AWG 1/4" Hole (6 AWG to 1/0 AWG Options Available)
  TEMCo 25 Lot 4 AWG Ring 1/4" Hole Terminal Lug Bare Copper Uninsulated Gauge $9.70
  
• $39 Bussmann CB185-150 150 Amp Type III Circuit Breaker
  Bussmann (CB185-150) 150 Amp Type III Circuit Breaker $22.60
• $30 Stinger SGP38 80-AMP Battery Isolator and Relay,BLACK
  Stinger SGP38 80-AMP Battery Isolator and Relay $14.99
• $23 StarTech.com Self-adhesive Nylon Cable Tie Mounts - Pkg of 100 - Cable organizer , TAA (HC102)
  2 of Startech HC102 Self Adhesive Cable Tie Mounts (Pack of 100) $8.95
• $8 Install Bay MANL100 - 100 Amp Mini ANL Fuses (2 Pack)
  Install Bay MANL100 - 100 Amp Mini ANL Fuses (4 Pack) $4.95
• $10 Permatex 22058 Dielectric Tune-Up Grease, 3oz. - High Performance Dielectric Grease Used To Protect Terminals, Spark Plugs, Wiring And Other Electrical Connections Against Salt, Dirt, And Corrosion
  Permatex 22058 Dielectric Tune-Up Grease, 3 oz. Tube $6.49
• $14 Install Bay BNMD250F Fully Insulated Nylon Male Connector 16/14 Gauge .250, Blue (100-Pack)
  Install Bay BNMD250F Fully Insulated Nylon Male Connector 16/14 Gauge .250, Blue (100-Pack) $9.32
• $12 Install Bay BTT Blue Insultion Displacement T-Tap Connector 16-14 Gauge - 100 Pack
  Blue Insultion Displacement Connector 16-14 GA - 100 Pack $6.31
• $6 Electriduct 3/8" Black PET Expandable Braided Sleeving Cable Mesh Flexible Wire Sleeve - 10 Feet
  3/8" PET Expandable Braided Sleeving- 10ft - Black $5.99
• $11 Electriduct 1/4" Black PET Expandable Braided Sleeving Cable Mesh Flexible Wire Sleeve - 10 Feet
  1/4" PET Expandable Braided Sleeving- 10ft - Black $4.96
• $5 Braided Sleeving, 0.125 in, 10 Ft, Black
  1/8 Inch PET Expandable Braided Sleeving- 10ft - Black by TechFlex $4.99
• NTE Electronics WH18-00-25 Hook Up Wire, Stranded, Type 18 Gauge, 25' Length, Black
  NTE Stranded 18 AWG Hook-Up Wire Black 25 ft. $6.40

Stuff I already had:

• 1/2" Ancor Marine red heat shrink tubing
• 1/2" Ancor Marine black heat shrink tubing
• Insulated female slide connectors.
• Split wire loom
• Solder
• Red lock tite
• Ring terminals for 16-22 AWG.
• Insulated butt splice connectors for 10 AWG.
  
• Tsunami Mini ANL fuse holder.
• Grommets used as vibration isolators on air compressor mounting plate.
• Self stick foam to insulate between alum plate and cab mounting brace

 

Air compressor is installed behind this seat back.



Behind the seat is a layer of mass loaded vinyl (MLV) sound barrier I hung as a last minute finishing touch on install. This was after carefully studying the air passageways back in there. I theorized it would be fine for the compressor for short bursts of filling the tires. The compressor has a fan that pulls air in from the bottom and blows it over the manifold and out the top. There is a 2"x2" hole that allows fresh air in where the seat back meets the hinge. This space was created when I pulled the plastic bin out. Heat seems to escape just fine out the top.



I measured ambient temperature of 58.4°F


I then dropped the MLV barrier and put the seat back up. I got my water sprayer ready in case of combustion accident.

I ran the compressor for ten (10) minutes straight, alternating between load and free flow. I did this with the doors closed.

After ten minutes, I opened the door and pulled the seat down and lifted the barrier and took these readings.

MLV sound barrier temp 98.7°F


Ambient temp behind seat 100.0°F


Plastic air compressor filter housing (disk shaped thing on left) 135.5°F


The air manifold itself. (not pictured, but it's the metal between the two compressor bodies.) 185.3°F


I feel this is acceptable for my intended usage of airing up at the end of trails. However, I'll probably repeat this test in the middle of summer when ambient temps are much higher, just to be safe.

 

lol Yes the wife looks. I've been getting a rash of it lately. But in her heart she can't be too mad because on the weekend kids were with me for a big part of it, which frees her up to do other things.

You're welcome. Parts list posted, as much as I could remember, hope it helps.

I showed my wife the pic of the finished air compressor. She looked at it said "Air Compressor" and walked away. lol She just doesn't care. I could do as ugly as a job as I wanted and it wouldn't even matter to her, as long as it worked, she would care about that.

Thanks!

Thank you for the complement!

Yup. Tapered threads. What I meant is if you take a 1/4" air fitting and throw a caliper on it and measure the ID it's like .30", and OD is .50" It just doesn't make any sense to me.

 

My only concern is overheating.

 

So I'm not done with my OBA just yet, but I'm taking a slightly different approach. Rather than running a permanent hose to the front or the back where I would then attach another hose to run all the way back past the compressor to the opposite tire I'll just flip the seat forward and connect directly to the pump when airing up (and actually the hose will be stored there already connected). The seat will thus be open while the compressor is running and there should be plenty of cooling. I've got a housing (more of a shroud as it is open on one side) to put the compressor in so that nothing else stored behind the seat can come in contact with hot parts of the compressor.

None of that will happen until next week at the earliest though, I'll post results in my "not as cool as Crom's" build thread.

 

I like that as well. Thanks.

 

That's a great idea. Less is more. I'm incredibly envious of those that have immediate access to behind the seats. I've had it up to my eyeballs with kids carseats blocking access. When my kids grow out of them, i secretly want to beat them like they beat the copier in office space. lol

I'm running 34' of combined air hose, 25' of that is 1/4". The longer air hose isn't necessarily a bad thing, it acts like a mini tank when moving to new tire to air up. Don't get me wrong though, i know it only helps for the first 2-3 seconds...Hose gets pressurized to 150 PSI. I discovered that even without a tank, I can use the compressor with hose to blow dust out the back of the truck. . An unexpected benefit.

One advantage of having an external air fitting, is if the weather is bad, the family can be inside and doors closed. I'm thinking rain (lol) or more likely strong wind, blowing dust.

I hope somebody found humor in the memes I added. I think they're hilarious.

Love your build, and excellent build thread, "The Diet Taco Rocks build thread"

 

Great Work as always! Those switches are piling up quick on that dash! Keep up the great work.