Newmar Ventana air brakes

"dpfreeman".....The sound is NORMAL. The front disc brakes will make this noise when you release them. They made me a little crazy at first, but I got use to it. There is another valve they can install (replace original) that will stop the noise. Some have said that Freightliner did it for free, while under warranty, while they were having some other work done. Others said they wanted to charge for it. I just got use to it.

wolfe10 wrote:
Thanks, Scott.

Said another way, they work the same.

If his Newmar is new, it will have disks, not the old drum style.

dpfreeman wrote:
Just bought new Newmar. When I step off of air brakes. They squeal, screech, or
Something. Is this normal?

No it's not "Normal" but nothing to worry over, our 2000 has 54k and it makes a whining noise when I apply the brakes.

It's just air traveling thru the system.

Thanks, Scott.

I have not worked on any of the single rear can (dual function)brakes but that would combine the two features of the two cans that are more common for rear brakes on air brake coaches:

Service brakes air applied, spring released.
Emergency/parking brake spring applied, air released.

Said another way, they work the same.

Tom/Barb wrote:

wolfe10 wrote:

That is why there are two "cans" on the rear brakes-- one for service brakes, one for emergency/park brakes.

I have 1 can each side of the rear axle, and 1 each side of the front.

all 4 have the hole for the "T" handle release for when there is no air and the vehicle must be towed.


Yes I have the big yellow button parking brake, that will dump the air of the rear Axle.

Tom/Barb,
Bretts (Wolf) explanation of how air brakes in general work, was accurate minus a detail. I don't think he meant there were TWO brake cans on each REAR WHEEL, per say. Without contradicting what Brett stated, I would like to re-describe what I think he meant. There is a SINGLE brake can on each rear wheel. But, unlike the front brake cans, which have a single function, the rears are what's called a DUAL FUNCTION brake can.The rear brake cans have different designs. Some look like two, stacked cans, one on top of the other. While others appear to be a single can. Both are a dual function can.

In that, the can is divided into two sections. One section is devoted to air application for service brakes. The other section is dedicated to a large spring that applies the brakes, when called for. . And, that happens when you PULL the yellow knob on the dash. When you pull on it, that valve releases the air pressure that is used to hold back the springs, in those cans. When the springs take effect, they apply the rear brakes ONLY, TO BE USED AS PARKING BRAKES.


That is a DOT regulation. Parking brakes MUST be applied MECHANICALLY. They cannot be applied by air or, hydraulics.

When you press on the "treadle" valve (brake pedal in the cab), it applies and routes air to ALL the brake chambers. That air, is regulated via that treadle valve. The more you push on it, the more air pressure is sent to the brakes, ALL OF THEM. I hope this helps clear things up a bit.
Scott

Take a look at this Newmar Forum link for a similar discussion... bottom line, nothing to be worried about

Our Newmar Dutchstar does it all of the time when in slow conditions. I believe it is air entering the system.

At the dealership I hear it on every Coach.

Ken

Not uncommon to have a squeal, screech, bark, or whatever from the air being released from the quick release valves when you release the brake pedal. 2 identical vehicles can sound completely different, each has it's own sound. Perfectly normal.

It's probably the air escaping from the bladder as you release the brake. Doe's it do it sitting still or just moving?
As my grandson said a 3 yrs old, "Big Truck, Gosh! PSSSSSSSSSSSSSSSSSSH!

wolfe10 wrote:

That is why there are two "cans" on the rear brakes-- one for service brakes, one for emergency/park brakes.

I have 1 can each side of the rear axle, and 1 each side of the front.

all 4 have the hole for the "T" handle release for when there is no air and the vehicle must be towed.


Yes I have the big yellow button parking brake, that will dump the air of the rear Axle.