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Onboard air


Nwcid

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***2-10-21 update below ***

I know I touched on this topic a while back but now I have some specific questions since I have a truck.  According to my analog gauges I have 120 PSI when my tanks are full.  

In my previous post I was asking about running air tools, which is no long a goal for me.  This will be used for airing up tires, blowing out filters, cleaning dust out of the UTV, etc.  

1. Where is the best place to access the air system for this use?  I have the 2 air lines coming out next to the trailer plug.  I am planning on removing the airlines, plugging one outlet and putting a standard air hose fitting on the other.  Does this work?  Which one do I need to put the fitting on?

2.  I have a little compressor now and it gets used not a lot, but fairly often.  Has anyone mounted a hose reel on the back of the cab with good success?  I know service trucks often have external mounted hose reels.  Does it take a lot of maintenance to keep functioning well?

3.  I have not checked to see what PSI my truck tires are, but I am guessing they are around 120 PSI.  Obviously this is toward the max of the compressor.  What PSI do you typically keep your tires at?  Does it make sense to run a lower pressures like in my pick up to improve the ride?  I have 2 - 20k axles so no risk of ever overloading them. 

Edited by Nwcid

2014 Volvo 630. 2016 Fuzion 325T, RZR 900 Trail 
675ah AGM, MSH 3012 inverter, 960w Solar.  (2016 Chevy 3500 DRW, backup)

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For 1. - I use a glad hand adapted to air line quick connect couplings. I connect to the trailer supply (usually marked red) and push in the red valve on the dash to supply dry air. The other glad hand is the foundation brake supply which is pressurized by the foot valve and or trailer brake control in the cab.

3. Truck tires especially drive tires are likely no where near maximum load in rv service. I use the load and inflation tables published by the Tire & Rim association. My truck is a single drive/dual wheel. Tires are at 70psi. which is minimum for the weight.

You are free to inflate to MAX but that psi is intended for the load per tire stamped beside that Max figure. Over inflation eleiminates the tires being step 1 in the suspension causing vibration and shock to be transferred to the truck and cargo. 
Traction and flotation is reduced on soft surfaces especially. 

"Are we there yet?" asked no motorcycle rider, ever. 

 

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Look on the back side of the dry tank. There is probably an un-used and capped access port.

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For airing tires and such, connecting to the red brake line works fine. As mentioned above, you have to push the red knob in to supply air to that line. There is enough restriction through the various valves that you can’t really get enough flow to use most air tools well.

I have a hose reel mounted between my headboard and the cab. 50’ of hose hidden away, I have not had any issues with the reel yet. My hose reel is hard plumbed to one of the air tanks with a ball valve before the reel. I keep the valve closed so I don’t have to worry about the hose blowing and loosing air.

Volvos with an Ishift have a pretty stout air compressor. Other configurations, some are good, some are a bit lacking.

Tires- the front tires have enough load on them you need to be @ 100-105 psi. The rear you can run softer, for me 75 psi is as low as I will go. The rims have taper beads, and you can knock a bead off the rime fairly easily at lower pressures. Lower pressures reduce the basketball effect on the rear tires, especially with wide base singles.

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Again I have no plans to running air tools, I will not even have any with me.  I just referenced this because that is what I was asking about before.  My only planed use is airing up tires, blowing out filters, cleaning dust out of the UTV, etc.  General maintenance stuff where I do not have to pack a separate compressor. 

I had originally thought about using the glad hands but I have no other use for the lines so I am just taking them off.  I just assumed pluming into the ports would be easiest.  I have no problem pushing the trailer brake button to put air to the hose.  Am I understanding correctly that the airlines that connect the trailer will not supply as much air as direct from the tank?  Even if they do not supply as much volume, will they still be adequate for my intended use?

For safety, I can put a shut off valve at the back of the cab where I attach the air fitting. 

I will look up a PSI chart for my tires. 

Edited by Nwcid

2014 Volvo 630. 2016 Fuzion 325T, RZR 900 Trail 
675ah AGM, MSH 3012 inverter, 960w Solar.  (2016 Chevy 3500 DRW, backup)

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For what you want you can do as I did.  Remove emergency air line (RED) and screw in a quick release air fitting.  The same as you use on all your air lines, that way you can use any airline that your use at home.  Just hook up air line, push in red knob on the dash and air tires.  You'll get somewhat the same volume of air that you would get if you went from the tank.  By doing this I have no problem airing the tires on the truck or trailer.  It will depend on how long you use the blow gun to blow out filters to determine if you have to wait for the compressor to build up.

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Our truck had a air operated sliding fifthwheel hitch. So there is a switch on the dash that operates that line only. After removing the commercial hitch I used that line to supply air as need for inflation purposes or what ever. Installed a quick disconnect on the end and have that accessible from the drivers side of the bed. Just under the bed above the step. It pulls out far enough to attach air line.

 

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Just for clarity, the red fittings and knob dennisvr speaks of is NOT the EMERGENCY AIR LINE! It is the trailer brakes supply line, and the only time it'll be involved in an emergency is if it gets snagged and damaged by highway debris. This will result in the uncontrolled application of the trailer brakes, followed by the truck brakes, as the air system empties through the damaged lines.

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15 hours ago, Nwcid said:

I had originally thought about using the glad hands but I have no other use for the lines so I am just taking them off.  I just assumed pluming into the ports would be easiest.  I have no problem pushing the trailer brake button to put air to the hose.  Am I understanding correctly that the airlines that connect the trailer will not supply as much air as direct from the tank?  Even if they do not supply as much volume, will they still be adequate for my intended use?

For safety, I can put a shut off valve at the back of the cab where I attach the air fitting. 

For connection to the trailer brake line, you don’t need a shut off for safety, the valves already there will handle that.

Yes, the point I was trying to make above is that you can get better airflow hooked direct to the tank. But for general inflation/blow gun the trailer line will be fine.

Edited by Moresmoke
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My truck also has/had (unbolted it last night) sliding air hitch.  The line going to the hitch is a very small one.  I did not look to see where it initially hooks into the the air system yet to see if there is a bigger fitting.  I am not sure what the hose size is, I keep seeing 1/4" listed, however it is much smaller than the 1/4" hoses I use with my compressor, I would guess it is 1/8".  It does not appear to have much volume.  

Next time I start the truck up, I will push the trailer brake knob in.  The line that puts out air will be the one I put the fitting on.  The one that does not will get capped.  It looks like I do not need an additional shut off on that line so I will not add one.  

I am still learning a lot about this truck and the systems on it.  The only time I have driven it so far is when I picked it up.  I was planning on starting work on it this spring as I do not have a long term inside place to work on it.  I got it into our shop to service the APU so I could use it to warm the truck up when I wanted to work on it in the spring.  Some of our plans have changed and it is still in our shop.  I am trying to get as much prep work done as I can while I have the opportunity.  I really appreciate all of the help and I hope my questions and your feedback help others in the future. 

I found a tool box I want to add and I am going to go pick it up on Friday.  I could take my pick up but I am going to take the HDT as the roads are currently clear and I want to get some more practice driving it before spring.  It will be a 400 mile round trip so I am looking forward to it. 

Edited by Nwcid

2014 Volvo 630. 2016 Fuzion 325T, RZR 900 Trail 
675ah AGM, MSH 3012 inverter, 960w Solar.  (2016 Chevy 3500 DRW, backup)

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8 minutes ago, noteven said:

Nwcid - does your truck have ABS?

It is a 2014 and it has a lot of other features, so I assume it does.  Where would I find that specific information?  It is not on the door sticker. 

2014 Volvo 630. 2016 Fuzion 325T, RZR 900 Trail 
675ah AGM, MSH 3012 inverter, 960w Solar.  (2016 Chevy 3500 DRW, backup)

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52 minutes ago, Nwcid said:

It is a 2014 and it has a lot of other features, so I assume it does.  Where would I find that specific information?  It is not on the door sticker. 

Yes a 2014 will have ABS.  

There will be an ABS light that illuminates during the system self test when you key "on". 

Reason I asked is if a truck is pre-ABS and is a "tractor" the brakes operate differently if the trailer supply valve is off or on. 

"Are we there yet?" asked no motorcycle rider, ever. 

 

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1 minute ago, noteven said:

Yes a 2014 will have ABS.  

There will be an ABS light that illuminates during the system self test when you key "on". 

Reason I asked is if a truck is pre-ABS and is a "tractor" the brakes operate differently if the trailer supply valve is off or on. 

Well the only time the supply valve would be on is if I am stationary and using air.  So 99% of the time the valve will be off, and 100% of the time I am driving. 

2014 Volvo 630. 2016 Fuzion 325T, RZR 900 Trail 
675ah AGM, MSH 3012 inverter, 960w Solar.  (2016 Chevy 3500 DRW, backup)

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Today I got my parts/adapters and went to work.

I put a plug on one side and reduced the 1/2" outlet to 1/4" found on air fittings.  

With the truck at an idle and air tanks full, ~110lbs I pushed in my "red supply" switch.  I had an air nozzle attached to the hose and held down the trigger.  Over about 45 seconds the pressure dropped to 100 psi and even holding the nozzle open for another minute or so it did not drop below that.  

This will be more than adequate for my needs.  It is unlikely I will go with a hose reel, I will just buy a 50', light weight 1/4" polyurethane hose.  They are light, store easy and will reach all around my rig.  I have one I use a home all of the time.  

2014 Volvo 630. 2016 Fuzion 325T, RZR 900 Trail 
675ah AGM, MSH 3012 inverter, 960w Solar.  (2016 Chevy 3500 DRW, backup)

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31 minutes ago, Nwcid said:

Today I got my parts/adapters and went to work.

I put a plug on one side and reduced the 1/2" outlet to 1/4" found on air fittings.  

With the truck at an idle and air tanks full, ~110lbs I pushed in my "red supply" switch.  I had an air nozzle attached to the hose and held down the trigger.  Over about 45 seconds the pressure dropped to 100 psi and even holding the nozzle open for another minute or so it did not drop below that.  

This will be more than adequate for my needs.  It is unlikely I will go with a hose reel, I will just buy a 50', light weight 1/4" polyurethane hose.  They are light, store easy and will reach all around my rig.  I have one I use a home all of the time.  

Go with a 3/8" air hose.  Trying to fill or top off tires with a 1/4" 50ft hose is time consuming.

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16 hours ago, Alie&Jim's Carrilite said:

Go with a 3/8" air hose.  Trying to fill or top off tires with a 1/4" 50ft hose is time consuming.

Yes, true, but this is for occasional use.  Even if I went from flat to full on the truck tires, the time difference in filling is less than 1 minute.  On the 12 lbs in the UTV tires we are talking seconds. 

Also the CFM of the 1/4 air hose is just under the rating on my compressor, the CFM on 3/8 is almost 2x the rating on the compressor.  

2014 Volvo 630. 2016 Fuzion 325T, RZR 900 Trail 
675ah AGM, MSH 3012 inverter, 960w Solar.  (2016 Chevy 3500 DRW, backup)

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36 minutes ago, Parrformance said:

I believe in this instance the larger air hose would act like an extra air tank, would it not?

Not a big air tank, a 50 ft long, 1/4" airline would have a volume of a cube roughly 3" square. A 50 ft long 3/8" hose would have a volume of a cube about 4" square. The big difference is that a 3/8" hose has more than twice the area of a 1/4" hose and will flow twice as much with a given pressure before considering flow restrictions thru couplers, fittings, flow resistance due to the walls of the tube, etc.

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