I feel stupid. Please help me not feel stupid.

This... may give the wrong impression of her purpose there.

 

Going to share a couple pics of my truck I have been working on. In the bottom pic you will see the S-Cam laying on the yellow box... top pic you will see the S-cam installed, about the 3 O'clock position of the brake shoes... it actually pushes the shoes apart making contact with the drum creating the braking action. I know this is probably starting on the wrong end of the horse but.... hopefully it will help seeing actual parts?? That is the Slack Adjuster laying on the plastic ( BLACK ) it attaches to the opposite end of the S-Cam. Top pic you see the new Spring brake / brake chamber (SILVER / GOLD) with a blue shaft sticking out to the right..... blue is just a plastic thread protector, Bottom pic you see the old chamber hanging by the 2 air lines by the red creeper. When you push the brake pedal down, air is sent to the brake chamber, which pushes on the slack adjuster which rotates the S-Cam, pushing the brake shoes out against the brake drum. Will add more pics of other parts soon.

 

Good heavens, OLDSKOOLER, she's not doing a brake job any time soon.
Why do my knuckles hurt again when looking at those pics? We may as well tell her how to install the seal while we're at it.

 

Just trying to help lol. Part of the function that makes it all work.

 

Good info would be how the constant air pressure of the red line(emergency) keeps the linings pulled away from the drums while the air supplied by the blue line(service) pushes the linings against the drums when the brake pedal is activated and that with no air pressure from either springs will hold the linings against the drums.

But you know.....with a better explanation than I can give

 

I know, that's great, really. It seems so easy to us, but I'm sure, it's very intimidating, like brain surgery to us. Years ago, we found out about "S" cams when they turned over, and the truck wouldn't move. Sure beats the old "wedge" brakes, hey?( that probably dates me)

 

Don't over complicate it. You don't have to know how it works to pass the test. You just have to know what to do. Basically, you have a service brake which is your brake pedal. Practically speaking it works just like in a car. Push it down while driving and you slow down. When parked you have 2 buttons to use. One is your tractor brake. Pushed in means no brake, pulled out means brake is applied. Also you have trailer brakes. Pushed in also means no brakes on trailer. Pulled out means trailer brakes are applied. Both of these need to be in to drive down the road. That is really all that you need to know as far as brakes are concerned. Best wishes and God bless you!

 

No one is going to chime in as you fear. Tease you maybe but not tear you down.

There are two systems in a big truck for braking.

One is springs on every wheel. There are 18 tires, but there are 10 wheels holding all the tires. Thus 10 springs. I think it might be only 8 due to steer axle not having springs. But bear with me.

When you take all the air out of the truck the springs lock. That truck will not move. This is the final safety. The springs have massive power inside of them.

The other part of the air braking is that there is air. Store the air in a tank. Dry it. Store it in another tank.

When you put your foot down on the driving to slow, some of the air flows to all the brakes and applies them. Because you already have enough pressure to drive with parking (Spring) brakes off you have plenty of air to brake.

Now.

There is a set of hoses that go to the trailer. One blue (Service) and the other Red (Emergency)

When all is well the trailer is part of the tractor. Now if for some reason that 5th wheel should break and the trailer gets away from the tractor, it's going to kill everyone on the interstate unless the spring brakes automatically lock down when it loses it's air through the emergency line. Poof. done.

This is literally all there is to air brakes in trucking. The rest of it is details upon details.

Usually need about 60 to 90 pounds to show that you have good air in the truck safe to drive. When you apply brakes you lose a little bit but not all of it. If you lost all of it then your air system has a leak in it. It needs to be fixed. At about 60 pounds there is a red light and alarm that should go off in your tractor. That means as you lose more your spring brakes are about to get to work stopping everything. On a downgrade run away that should give you a chance. But on a interstate in rush hour it's not welcome. There are parts to the braking system which further defines...

Slack Adjustment. A part of the braking system that must travel within a certain distance (About a inch and change...) to apply the brake pads to the drums. If you are not in adjustment, you literally do not have brakes. All the springs from God himself will not apply a blessed pound anywhere.

ABS, anti lock braking. If you slam the brakes on a semi on ice, that truck will do what it needs to do using ABS to keep the wheels rotating. Rotating tires on pavement means traction, traction means a fighting chance. If you don't have ABS you are now skidding and in physics, skids go straight ahead wherever it might be moving as a mass.

Ergo:

Link:http www.liveleak.com/view?i=1e6_1493296447 insert s:// in the space between the word HTTP and WWW. To make the link active. It guides you to a short video showing a mountain braking problem. This website no longer correctly shows me linked material.

 

You're right. Everyone coming from the showers will be tossing their dirty towels to her......