Downside to air trailer brakes?

[Exile]

thinking over building my own fifth, and wondering what the down sides are of going straight air brakes, maybe on light commercial style axles.

 

Upside:

Commercial parts

All air, no converter systems

Maybe have air ride suspension with it

 

Downside:

Resale? Lgt truck could not pull, but maybe trailer too heavy for that anyway

I could not tow trailer to get parts with my pickup while building until i bought a hdt

[MrSeas]

Something like this has worked for some of the members here....

http://www.bludotinc.com/index.html

[SIBERNUT]

I love Bludot on a pre-made trailer. But I'd go full air on anything I'd build. AND- here in the northeast, I'd build in a lift axle (or 2).

[Exile]

I see Bluedot has a nice range of braking solutions, thanks for the link.

 

Good idea on the lift axle, would help with maneuvering. I had considered a lift axle on the tractor, but not the trailer.

[noteven]

thinking over building my own fifth, and wondering what the down sides are of going straight air brakes, maybe on light commercial style axles.

 

Upside:

Commercial parts

All air, no converter systems

Maybe have air ride suspension with it

 

Downside:

Resale? Lgt truck could not pull, but maybe trailer too heavy for that anyway

I could not tow trailer to get parts with my pickup while building until i bought a hdt

 

 

 

Other than the two downsides you mention - nope. If you live in one of these (silly) jurisdictions that allow operation of air brake vehicles and equipment on public roads without an air brakes endorsement I would recommend you take a course anyway so you understand how to operate the system.

[phoenix2013]

I don't see any downside, other than cost perhaps (but safety and superb performance should always be put ahead of cost), to air braking systems, either the BluDot air over hydraulic system, or full blown air braking axles.

I've had a chance to "pioneer" the BluDot conversion on my fifth, doing it on a bunch of other fifths and then to "school" bunch of people how to do it on their fifths.

Here's a photo album https://picasaweb.google.com/101586473487712642142/BluDotInstallation of my initial conversion and article I wrote on RV brakes you might find "amusing". (Mixed in the album are picture of couple other conversions I did on other fifths)

 

The question of the ease of re-sale always comes up in this regard, what do I do if I want to sell it again and the next owner does not have a "capable enough truck" to take advantage of the BluDot system or the the full blown air system. You partially answered your own question by assuming that a fifth that has or requires such braking system probably is not suitable for a pickup or should not be pulled by a pickup.

My thought about doing this and many others who have done it (and those who bought fifths with semi axles) generally was, "we want the most capable and safe braking system to TAKE CARE OF US, OUR SAFETY AND OUR LOVED ONES for the next bunch of OUR RVing years. To put it in a more rude context, "why should I put up with a substandard (and scary) brakes for the benefit of of some cheap fool in the future who hasn't graduated beyond the pickup".

Incidentally with a BluDot it is relatively easy to "re-convert" it back to the crap system that was there before so that the fool with a pickup can drive it off into the sunset.

[Exile]

Found these guys have a great website discussing axle options and trailer configurations.

 

http://www.pjtrailers.com/uses/hot-shot-trailers/

 

They also have a page showing their air ride axle options and axle lift options.

 

Much easier to back in with back axle of 3 lifted. Tires and axles will take the load at low speeds and infrequent use. Lifting two axles might be a little dicey.

[noteven]

Low speed or "creep" ratings of commercial truck axles is much higher than highway speed rating. A 46,000lbs capacity tandem set has a creep rating around 65,000lbs. For example when a dump truck hoists to spread a load many lbs transfers to the rear axles.

 

The axle/suspension OEMs you are considering will be able to tell you what their low speed capacity is. The tire weight police will of course put up a Big Fuss as if there is absolutely zero extra capacity engineered into that tire... 3160lbs good to go. 3200lbs & BOOM! and your unit will suffer 4 blow outs and immediate loss of reverse control and back right over the bluff at Carlsbad State Beach and crash on the beach below.

[Exile]

I don't see any downside, other than cost perhaps (but safety and superb performance should always be put ahead of cost), to air braking systems, either the BluDot air over hydraulic system, or full blown air braking axles.

I've had a chance to "pioneer" the BluDot conversion on my fifth, doing it on a bunch of other fifths and then to "school" bunch of people how to do it on their fifths.

Here's a photo album https://picasaweb.google.com/101586473487712642142/BluDotInstallation of my initial conversion and article I wrote on RV brakes you might find "amusing". (Mixed in the album are picture of couple other conversions I did on other fifths)

 

The question of the ease of re-sale always comes up in this regard, what do I do if I want to sell it again and the next owner does not have a "capable enough truck" to take advantage of the BluDot system or the the full blown air system. You partially answered your own question by assuming that a fifth that has or requires such braking system probably is not suitable for a pickup or should not be pulled by a pickup.

My thought about doing this and any many others who have done it (and those who bought fifths with semi axles) generally was, "we want the most capable and safe braking system to TAKE CARE OF US, OUR SAFETY AND OUR LOVED ONES for the next bunch of OUR RVing years. To put it in a more rude context, "why should I put up with a substandard (and scary) brakes for the benefit of of some cheap fool in the future who hasn't graduated beyond the pickup".

Incidentally with a BluDot it is relatively easy to "re-convert" it back to the crap system that was there before so that the fool with a pickup can drive it off into the sunset.

Yep, i see your point. Nice article. Couldn't agree more. Things have not improved since you wrote it. Saw a f250 at the dealership with a 45 ft rig, and the headlights looking at the clouds. Told salesman i was going to tow with a heavy duty truck, and he said Dodge makes the best. I didnt bother taking the conversation any further.

[Jack Mayer]

If building from scratch I would not put on BluDot, even though I have had it on 4 trailers now. I would put on full air brakes. The trailer you build will be too heavy for anything but an HDT, in reality. So resale should not be an issue. Resale of a homebuilt trailer (no matter how nice) is already limited. I would not consider resale at all in my planning. HERE is a link to a BluDot presentation I did at the HDT Rally a few years ago. Along with Henry's info you may find it helpful. Let me know if the link does not work.

 

BTW, converting the BluDot back to a "conventional" electric/hydraulic actuator (specifically a Tuson actuator) is about a 2 hour job....and it only takes that long because I run dual BluDot actuators because of Dexter caliper size. So more to remove. And you do not have to re-bleed the system if you do it correctly. Cost (to me) is around $600. I've done this two times now (convert for a resale) so I think I have a good handle on it.....(this is for other people...you would not use BD anyway).

 

With regard to a lift axle on a homebuilt....the direction you describe you would have dual tandem axles. Why lift one? You gain nothing IMO, and add a LOT of complexity that you specifically state is counter to your design goals. I would not even consider a lift axle, but that is JMO.

[rickeieio]

 

 

With regard to a lift axle on a homebuilt....the direction you describe you would have dual tandem axles. Why lift one? You gain nothing IMO, and add a LOT of complexity that you specifically state is counter to your design goals. I would not even consider a lift axle, but that is JMO.

 

Okay Jack, you have me wondering. Since he's already thinking way outside the conventional box, what about using a spread axle config.? Better ride, but then a air lift could be of real benefit.

[G&K]

Spread is a fascinating thought. Only issue might be more awkward tire well intrusion in an axle-less configuration.

[phoenix2013]

Yep, i see your point. Nice article. Couldn't agree more. Things have not improved since you wrote it. Saw a f250 at the dealership with a 45 ft rig, and the headlights looking at the clouds. Told salesman i was going to tow with a heavy duty truck, and he said Dodge makes the best. I didnt bother taking the conversation any further.

 

Exile, just as a point of reference, I wrote and published that article on brakes in Winter of 2006, I guess the RV industry needs a "little more time".

[Exile]

Was actually considering three singles, but they might not be available with air brakes. Will research further.

 

Thinking of Lowering deck down till wheel wells are maybe 5" above the deck. Tougher to deal with dual sized wells.

 

I figured a lift axle would only consist of an isolation valve, a bleeder valve, and a lift spring. I've heard of guys using a nylon strap to lift an axle once it is bled down. Add a 25$ electric winch, and viola a pushbutton lift.

 

I might be wrong about the final weight, was hoping to keep it under 25k. i plan on framing with 2x4 construction, using thinner wood sheathing on the interior, 5/16 or so. Cedar or something light on the exterior over osb.

 

Will have to find weights and start adding them up to get an idea of the total weight.

 

I see even a trailer that costs 80k "on sale" is just made of 2x2s and 1/4 " plywood, and as a woodworker, it makes me cringe to touch anything in them.

 

I see the blue dot system is verysimple, just a booster and a volume tank.

 

Youre probably right on the resale. Would sell as a house, not a trailer, though.

 

Agree that air brake endorsement is a key thing to have. Class A cdl with air brake endorsement is in my wallet.

[peety3]

Lift axle adds complexity beyond what you probably want. My suggestion? Go with a simpler solution, especially since loaded vs. empty weight differences are negligible: figure out which axle you want to be "primary" when backing (forward, most likely, for easier pivot/swinging), and make sure the leveling valve is on the other axle. Rig two 12V normally-closed air valves on a SPDT (single-pole double-throw) switch that has no center-off position (in other words, an A-or-B switch). When the switch is in the A or road position, valve #1 (fed from the leveling valve) is open, so that both axles get the same air pressure, and therefore the same load. When the switch is in the B or backing position, valve #2 (fed from your trailer air brake supply line) is open, so the front axle gets 120psi air and therefore takes maximum load; the secondary axle will level itself such that trailer weight equals (pin weight plus axle 1 load plus axle 2 load). This will shift the weight towards the primary axle and likewise the CoG and pivot point. The secondary axle will likely scrub a bit, but it'll be loaded a lot less than normal.

 

If by chance your air suspension says "don't exceed 100psi", then perhaps put a regulator on the line into valve 2. So...some air line, two valves, a switch, possibly a regulator, and some wiring.

[Jack Mayer]

How long is this going to be? WIth what you are doing with residential fixtures, wood construction, thick walls, heavy foam insulation, large genset, hydronic system, etc I don;t see it being under 25K lbs unless the trailer is pretty short. I was thinking a 43'+ for what you wanted...but I don't know where I got that figure from. If shoreter, you may be able to get the weight down. Regardless, I'd want tandems. You may be able to do a single axle tandem if you are short enough. But probably you are not in that category.

 

I really cannot see the value of a lift system.....I've been running heavy triple axle trailers fulltime for 15+ years and NEVER had an issue. Not a single one. Scrubbing tires does occur, but is limited with proper backing technique. I'd much rather deal with that than the complexities of a lift axle. IF I did one I'd do as Peety said. A limited "lift".

[G&K]

I would seriously consider merging a spread axle configuration with Peety's "lightened" axle trick.

 

You could move the trailer pivot point way forward.

 

I've been a couple of scenarios in the last month where that would have been very handy. My backyard for one where I have to come off a narrow lane onto a 50' long parking pad. The faster I can get the trailer turning the better this works.

 

Geo

[SIBERNUT]

You guys missed the "Northeast" in the comment. MANY states up here charge tolls by axles on the ground. If you lift one going into the booth, lower rate. Many tankers are now being spec'd with a lift axle on the trailer for empty backhaul tolls. If you are REALLY sharp, and hit the button at the right time, you can scale at a lighter weight for tolls by shifting the load with that axle as you cross the plate. Used to do it all the time with a slop load in a tanker, but you gotta' be on your A game to do it. TWICE IN A ROW like on the PA pike, getting on AND getting off.

[G&K]

You could sure get spoiled fast with that system!!

 

I hate to think what the install/repair cost would be.

 

Geo

 

 

LOL - anyone for steerable axles on the trailer? I've often wondered if someone building one could incorporate a set.

 

As your backing up, the wife, so, or even yourself in the cab, turning the trailer wheels. Center locks for driving forward.

 

Just a random thought.

 

[peety3]

You guys missed the "Northeast" in the comment. MANY states up here charge tolls by axles on the ground. If you lift one going into the booth, lower rate. Many tankers are now being spec'd with a lift axle on the trailer for empty backhaul tolls. If you are REALLY sharp, and hit the button at the right time, you can scale at a lighter weight for tolls by shifting the load with that axle as you cross the plate. Used to do it all the time with a slop load in a tanker, but you gotta' be on your A game to do it. TWICE IN A ROW like on the PA pike, getting on AND getting off.

Check your laws carefully though. At least in WA state, the axle controls must be out of reach of the driver. And with an RV trailer, I doubt there's enough difference between the loaded (...full of sh*t...and water and food and toys?) and empty (...drain the tanks and leave the toyhauler bay empty) weights to justify a true lift axle.

 

In my typical crazy brainstorming phase, I put together a rough draft of a three-axle airbag controller that could handle 20k (commercial) axles, account for the 17k/axle limit on "tight" spaced tandems, and allow me to choose a balanced load distribution across any 2/all 3 axles, a targeted weight distribution with maximum loading on any 1 (or 2) axle(s) and overflow on the 2nd/3rd axle, an all-up configuration, or an all-down configuration, but finally decided that my dream 53' trailer just wouldn't push me into a need to do something that fancy, nor did I want to deal with CA's crazy axle placement laws.

[shorts]

While I was looking at the Dallassmith suspension website it looks like they are using spindle and hub assemblies from steer axles bolted to their suspension modules, with that being the case why not either use their suspension units or spec an airride suspension with 12 or 14k single wheel axles? I would imagine that a 24 to 30 inch floor height could be achieved with 60 to 72" between the wheel wells and all of the advantages of standard OTR parts except for the axle width or tube length and width spacing on the suspension parts. Choose a frame width that would be compatible with the standard RV tank sizes to make component sourcing affordable

[Exile]

Thanks for all the ideas. I'm thinking 10 or 12 k air ride air brake axles.

 

Trailer length 32 on the lower deck maximum. Still need to put numbers together for weight.

 

And just need to figure out cheap and good way to raise the deck in the garage. Lippert bed lift is about the same price as a 9000lb car lift.

 

Saw someone make a lift from a junked forklift. I like that idea.

[G&K]

Check your laws carefully though. At least in WA state, the axle controls must be out of reach of the driver. And with an RV trailer, I doubt there's enough difference between the loaded (...full of sh*t...and water and food and toys?) and empty (...drain the tanks and leave the toyhauler bay empty) weights to justify a true lift axle.

 

In my typical crazy brainstorming phase, I put together a rough draft of a three-axle airbag controller that could handle 20k (commercial) axles, account for the 17k/axle limit on "tight" spaced tandems, and allow me to choose a balanced load distribution across any 2/all 3 axles, a targeted weight distribution with maximum loading on any 1 (or 2) axle(s) and overflow on the 2nd/3rd axle, an all-up configuration, or an all-down configuration, but finally decided that my dream 53' trailer just wouldn't push me into a need to do something that fancy, nor did I want to deal with CA's crazy axle placement laws.

 

Peety, I'm kinda slow, but couldn't we unweight the back axle in the tandem config on my 780 to enhance parking at low speeds?

 

I really like your idea. The mind boggles.

 

Geo

[VegasFlyer]

Unless ou are building a fairly small trailer, putting a lift axle on a furnished fifth wheel RV trailer would be somewhat counterproductive.

 

If you have a trailer weighing more than 20,000 pounds, which most likely be the case, as soon as you lifted the axle, you would overload the other one. Now you could put on three dual wheeled axles and have one be a lift axle, but that would be overkill.

 

When you see lift axles on commercial trailers, they are installed in applications where there is a major difference between the empty or unladen weight and the fully loaded weight.

 

As to the spread axle set up, it would provide somewhat better ride, though you would not have many fans from the folks who run RV parks when you maneuver around tight turns and leave your tire calling cards.

 

To the original question, air brakes on the trailer are a great idea and argueably the safest way to handle the braking for a heavy 5th wheel RV.

[rickeieio]

Post #8 discusses why an air lift would work for low speed maneuvering, thus making a spread axle feasible even in a campground.

 

Yes, we're way off topic, but it sure is interesting.