Air Force One Brake Problem

[aikihito]

Whenever we connect the air brake line to our tow car, our mpg drops about 15%. The coach side Air Force One install has been checked and is correct. Any ideas about what may be causing the mpg drop when the air brake line is connected to the tow car?

[TripleEEE]

Sounds like the brakes on the TOAD are being applied slightly.

You might want to refer to the manual.

https://www.demco-products.com/asset...ts/TB20050.pdf

[JCM]

Would the triple owner please contact me as I just purchased a 32 Commander with a Workhorse chassis.
To the Airforce 1 user - when you hook up your braking system -- you are now towing extra weight = decreased mileage.

[Sbrownstein]

True that the TOAD weighs something, but a 15% decrease is more than I would expect unless you spend you time climbing mountains. On the other hand, it ain't much for trying to overcome brakes and drive. By now something would have seriously overheated.

[redcolorado]

When I tow my 2015 Colorado with my 2008 Bounder gasser my mpg drops about 7%.
Have someone follow you to see if your toad brake lights are on, that would indicate dragging brakes.
Get a ir thermometer and check your toad brakes for heat after towing.
You could install a direct means of knowing if your toad brakes are applied like I and others have done. There are many ways to do that. This one is mine.

[phays]

Are you saying that when you tow your toad without the air line connected you get better mileage?

When you tow, is the break-away switch cable always attached?

Doesn't your AF1 install have a toad brake indicator light and does it light only when you apply the coach brakes?

How large is your coach and how large is your toad?

How old is the AF1 system?

[Mallie]

I think we would all be curious to know what you MH is and what car you are towing.

[aikihito]

I tow a Subaru Crosstrek with my 2018 DSDP 4369. When I attach the air brake cable between my coach and tow car, my mpg drops from 7.8 to 6.7. The installer rechecked the coach-side AF1 install and says it’s correct. If so, the problem must be on the tow car side. Any thoughts on how to check this out?

[twinboat]

When hooked up, do you hear constant air leaks ?

Do your air gauges drop and fill constantly ?

Does it purge constantly while the engine is running ?

Not based on anything but a guess, but any of the above could cause excessive air compressor running, adding more load to the engine, effecting MPG.

[alank]

Originally Posted by aikihito

I tow a Subaru Crosstrek with my 2018 DSDP 4369. When I attach the air brake cable between my coach and tow car, my mpg drops from 7.8 to 6.7. The installer rechecked the coach-side AF1 install and says it’s correct. If so, the problem must be on the tow car side. Any thoughts on how to check this out?

Are you sure you shouldn't be saying: When I hook my Subaru up to my DS, my mpg drops from 7.8 to 6.7. How much have you towed the Sub without the air hose to verify it's the air hose that reduces the mpg. rather than the weight of the Sub? In my experience, a reduction of 1 mpg doesn't sound that far off to pull a toad.

[Sbrownstein]

I know this is a flyer, but those numbers aren't that far from the ratio of the GVWs of the TOAD and the coach. In other words, the Crosstrek adds something between 12 and 16 percent to the total package.

Just sayin!!!

[C.Martin]

Just watch the cylinder while someone connects the air line...does it move?

If tha isn't it...might touch the hubs to see if a brake is dragging or bearings are shot.

[Sbrownstein]

As many others have chimed in on this thread already, it is not a good idea to run an auxiliary braking system without a cab indication LED that the TOAD brakes are being applied.

Doing so is pretty trivial as well.

[Mallie]

The airforce one has an indicator in the form of an LED in the windshild of the of the towed, should be visable from the rear camera.