Alert !!!!/ Toad Air Brake Tn rally

[0533]

Several of us who attended the rally in Tn. had the Air Force One Toad Air Brake system installed at the rally.

We had ours installed last Thursday and left for jacksonville the next day. Spent Friday in the Columbia area and the next two nights in Fort Clinch State park on Amelia Island Fl.

We used the HWH leveling system for the two day stay and all went well. On Monday am at 6am we started coach and could not get full air on either side and had a noise coming from the back. We were heading to Prevost for a scheduled appointment and decided to keep an eye on the gages and move along.

Once at Prevost and up on the rack we could see that the new Air Force One Tank and valve that was attached to the D/S rear drive near the bag but very close to the frame sheared of at the T fitting between the tank and the valve, the valve was just tangling from the plastic tubing.

What had happened was that the Air force one guys ( who by the way were really nice people and are going to cover the cost of my time at Prevost and wanted to find out what happened) had not anticipated just how far down a Prevost goes when it is in the leveling phase and in my case the auto leveling phase, the bottom of the coach just sheared off the fitting, it snapped like a twig.

Please take a better look at each or our installs and see that they are not too close to the frame, at the transmission arch.

Bruce

[Ray Davis]

Sounds like a really important thing to remember when having these installed, i.e. run it through a full range of motion by letting all air out, and pumping up again?

[lloyd&pamela]

I had one installed. They sent me replacement LED's since ours did not work when we left the RV park.

As a newbie I do not understand everything that Bruce described. What should I do and look for? Thanks.

[Jon Wehrenberg]

Lloyd,

The system should not use air except when applying the service brakes if I understood the explaination.

What Bruce is saying I think is that when his coach was sitting low it sheared off a fitting on the device that separates the toad air system from the coach air system.

What I do not understand is why Bruce heard air at times other than when he was applying brakes.

For your peace of mind you should do a pre trip inspection to verify everything is OK. After you hook up the Jeep, with the system completely aired up shut off the engine. Release the parking brake. The brakes should release, there should be a slight drop in the air pressure and then it should stop. The air pressure should hold where it is and there should be no sound of escaping air.

Then apply the service brakes and hold them. Again there will be a small drop in pressure as they are applied, but the drop should again stop almost immediately. Like before there should be no sound of air escaping. If you want to really be sure have Pam walk around the outside while you are doing this to listen carefully for the sound of air escaping. If she hears any you have a problem.

What Bruce said about not being able to raise the coach would strongly suggest the component in question was attached to the aux air circuit. Bruce, we need a more detailed description because the only air escaping should occur when the service brakes are applied.

[lloyd&pamela]

Thanks Jon. We are her in Gatlinburg until Sunday AM. We will check them first thing in the morning. Thank you,
Lloyd

[Jim Skiff]

I have contacted Peter at SMI Brake and expressed my concerns.
He has been given codes and will be available to address member issues.

Jim

[tdelorme]

Bruce, I'm just glad you guys made it to Prevost safely. You have better nerves than I do. I just don't think I'm brave enough to head out on the road with an air leak that I can hear. I would expect these guys to do what's right as far as covering your repair cost and hopefully learn from your experience.

Thanks again for your willingness to let Jan explore your coach, she is still raving about it. Travel well.

[Jon Wehrenberg]

Just so everyone is completely clear...your brakes systems have zero pressure on the brake chambers or lines leading to them when the emergency brake is on and the service brakes are not applied. I presume when Bruce tried to air up his coach and raise it to the ride height he had the brake on and his foot was not on the brake pedal.

Air pressure to the emergency brake side of the brake actuator RELEASES the brakes which are held in place when parked by a huge spring.

The service brake side of the system has no pressure whatsoever unless and until you step on the brake pedal.

For a system that is supposedly connected to the brakes to be releasing air constantly something is wrong. Especially when the leak is large enough to prevent the air suspension system from pressurizing sufficiently to raise the coach.

I think this is important enough for anyone who had this installation to verify the components that were installed were connected to the correct part of the air system.

[Ray Davis]

In thinking about what Jon said, I went to the SMI site to see if I could find ain installation guide.

I wasn't successful in that, but I did find a "plumbing" diagram.

It's not 100% clear, but it looks like they expect to tap into an air supply system AND then also to the brake.

I believe they show this on this diagram

http://www.smibrake.com/GetProductImage.aspx?ID=4

as "supply-air connection", and "metered-air connection".

I assume metered would be the brake lines, but I will admit to guessing here.


Ray

[Joe Cannarozzi]

"After you hook up the Jeep, with the system completely aired up shut off the engine. Release the parking brake. The brakes should release, there should be a slight drop in the air pressure and then it should stop. The air pressure should hold where it is and there should be no sound of escaping air.

Then apply the service brakes and hold them. Again there will be a small drop in pressure as they are applied, but the drop should again stop almost immediately. Like before there should be no sound of air escaping."

What Jon has described here is critical and is worth repeating even if only 1 more member soaks it in.

This is a standard pre-trip inspection that should happen EVERY time you head out. It only takes 2 minutes. This is also the way we isolate a problem and helps pinpoint what.

Adding to this would be to air up and shut the bus off before you release the brakes, if there is a evident air leak at this point it would/could probably be in a suspension component. An air bag or a line to them or a ride height valve or norgren valve or possibly less common, a tank or tank fitting.

If all good, next, when the parking brake is released but before service brakes applied you shut the bus off and you encounter a leak that would be "emergency air" leaking, either a maxi chamber or an air line leading to them or possibly a valve.

If again all good then with the emergency brake off and the brake pedal applied and you shut the bus off and you hear a leak that would be "service air", possibly a brake diaphragm, (also incorporated into the maxi) or a line leading to that.

The maxi (brake chamber) has 2 air lines going to them. 1 is emergency air that airs up (by pushing the parking brake button) the side of the diaphragm opposite the large spring, just neutralizing (not overwhelming), the large parking brake spring thus releasing the parking brake.

For all you scuba divers think of it as when you release the parking brake your creating neutral buoyancy within the chamber by putting emergency air to the opposite side of the diaphram as the spring.

The other air line is service air and it is introduced (by stepping on the brake pedal) to the side of the diaphragm WITH the spring and that service air combined with the force of that spring DOES OVERWHELM that emergency air on the other side of the diaphragm thus engaging the brakes and with as little as or as much air as is introduced depending on how hard you apply pressure on the brake pedal.