Community Forums

wil01 · 02-17-2015, 09:15 AM

This story is true and involves a 2007 Kountry Star diesel pusher, a model 625 HWH jack system and an Air Force One auxiliary braking system.

I traded in a 2000 Kountry Star for a 2007 Kountry Star and the dealer moved the Air Force One system from the 2000 to the new, to me, 2007 Kountry Star. The original jack system on the 2007 had a bad control panel, and the manufacturer of that panel is out of business so no repair was possible. The dealer installed a new HWH 625 jack system and when all was done, we started out.

After about 1,000 miles we ended up in a campground in Florida City FL for about six weeks. While at the campground, it was necessary to move to a camp site on the other side of the campground – about 1000 feet with several tight turns on narrow streets. While inspecting the new camp site before backing in, I noticed a loud hiss of air escaping from somewhere, and I decided to have a RV service company inspect the issue and take care of what turned up. Their inspection determined that the input air line to the Air Force One MH air input to rhe control unit was broken completely off, and the unit itself was damaged. They had the part in stock and after replacing the damaged unit all works just like new.

The purpose of this story is to provide an actual result of what happens when an air supply fault to and/or from the Air Force One occurs. Some have expressed concerns about what would happen if such a condition were to occur. SMI states that the air system of the MH is protected in such situations. Well, as major a fault as could occur did occur, and if this interests you read on.

The cause of the damage was that the Air Force One MH control unit was installed in a position that allowed the drive shaft to strike the unit and cause the damage in some situations when the air bags were deflated by the HWH jack system when operating in the auto-level function. As you most likely know, the first action of the auto level system is to deflate the air bags and then level the rig. It doesn’t deflate the bags the same amount every time, but one time it deflated enough to do the damage. The cure was to relocate the AF1 MH unit away from the danger.

Since I have a brake indicator powered from the load side of the toad brake light, I know there was no problem when setting up at the last camp site before the move. When I moved camp sites, I had no indication of the problem while moving from one camp site to the other because I didn’t connect the toad to the MH. I didn’t notice the air gauges, but the low pressure alarm stopped sounding, and I was able to drive away normally.

During the move, I drove no faster than 10 mph and used the brakes often because of the tight turns. Everything, including the brakes, worked as usual. The only indication of a problem was the loud hissing sound of escaping air I discovered after getting out of the rig.

After setting up at the new camp site, I started the engine to observe the air gauges. The front air gauge was at about 80 psi and the rear air gauge was at about 70 psi. With the engine idling, they stayed at that air pressure.

It took the service company a couple of days to come and inspect the problem, and while waiting, I checked the air pressure at idle several times. The low pressure alarm would always stop sounding and the air pressure would remain at about 75 psi. After the problem was fixed, the air pressure at idle returned to 125-150 psi.

I didn’t drive the rig on the road with this problem, but all indication are that above idle speed, the air compressor will keep up with the required air pressure for safe braking and normal driving with a break in the air system.

I hope this story is helpful for those considering an Air Force One toad braking system. It is truly an outstanding system providing perfect toad braking without any adjustments required. The rig stops in the same or less distance with the toad attached as without the toad attached.

Good Luck!
Wil

PushedAround · 02-17-2015, 09:23 AM

Good to hear that a line failure in the AF1 setup it does not incapacitate the rest of the air system. With so many out there, I'm sure that we would have heard of such problems by now.

BarryN514 · 02-19-2015, 04:11 PM

So your saying that there was no fault of the AF1 but basically when it was installed that caused the problem?

twinboat · 02-19-2015, 04:45 PM

You say that
"all indication are that above idle speed, the air compressor will keep up the required air pressure for safe braking and normal driving"

Did you confirm that the air would climb above 90 lb`s.

At 75 lb`s pressure, you are below the working pressure of 90 to 120 lb`s and only 15 lb`s above, spring brake application.

If you can not build and maintain at least 90 lb`s, you do not have safe brakes.

At least clamp off the leak, before driving on the road.

Just my opinion