Air Brake Noise

[slabman]

Each time I release my service brakes I hear the sound of air being dispelled through what seems like a couple of flapping rubber membranes. The sound is analagous to one of those old "Whoopie Cushions". (Anyone care to remember back that far?) I don't remember my Freightliner chassis doing that and was told this noise is completely normal. Is it?

[slabman]

Each time I release my service brakes I hear the sound of air being dispelled through what seems like a couple of flapping rubber membranes. The sound is analagous to one of those old "Whoopie Cushions". (Anyone care to remember back that far?) I don't remember my Freightliner chassis doing that and was told this noise is completely normal. Is it?

[Don (W5IT)]

Well Bob each system is differant but also alike.... They operate in the same manner, just differant ways.

So there are sometimes those that make strange sounds.

If it were mine makin that type noise there is NO way I could convince Cathy it was not ME releasein some air/gas makein the noise.

[OC-RV]

Our coach brakes make the same sound - also Spartan - Mountain Master GT

[76dc]

I hate that noise, sure other people in campground do when I leave early in the morning. Spartan said it's the valve they use. Hope they change it soon.

[Cruzer]

Yeah, we noticed that too. We call it the "Gonzo" noise. I didn't have that on my Freightliner but I do on the Spartan. The difference is in the brake relay valve used.

But, I'm not complaining, because the Spartan valve is a better valve.

Brake relay valves serve to trigger the main rush of air to your brake pancakes via a pneumatic relay so that you don't have to run all that air volume through the brake pedal valve. Then, as soon as you release the brake pedal this valve immediately dumps all of the air in the brake diaphragms to atmosphere so that the brakes will release. That way all the air doesn't have to back up through the pedal to exhaust, which would nean your brakes would drag until that happened.

The Spartan relay is a much faster dumping relay. When you release the pedal the brakes are immediately released. The downside is the "flatulence" noise that it makes when it does that. On my Freightliner I didn't have that noise but the brakes released much more slowly because the air drained off slower.

Some day when it's slippery and you want the brakes to release quickly you'll be glad you've got "Gonzo" under the hood.

Besides, when you are stopped at a light waiting for pedestrians to cross in front of you a well timed brake pedal "twitch" can brighten up your day.

[rebelsbeach]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Besides, when you are stopped at a light waiting for pedestrians to cross in front of you a well timed brake pedal "twitch" can brighten up your day </div></BLOCKQUOTE>

Color me..... GUILTY!!

Great explanation Mark!

[OC-RV]

Cruzer - Excellent post response as usual - Enlightening Thanks, John

[Cruzer]

Bob, if we ever get side by side at a crosswalk some day I pity the person who tries to walk in front of us. It'll be "dueling banjos" with a Spartan twist.

[slabman]

You guys are too much.

Sure hope I run into some of you guys at the Spartan Rally in Charlotte. Who's going to be there?

Think what a campground full of Spartan brake systems would sound like if we all release those brakes at once?