Brake lag?

I’m glad physics is reversed.

air is compressible, fluids are not.

fluids have an immediate reaction to pressure in closed systems.

air has some lag as air is channeled and compressed by additional air in the system.

Here is something from Ontario’s brake system handbook ...


Air brakes differ from hydraulic brakes
Most brakes are located at the wheels of a vehicle. The force you apply to the brake pedal is transmitted to the wheels to make the brakes operate. There are two main ways in which this force is transmitted - hydraulic brake systems and air brake systems.

Hydraulic brake systems are used as the main braking system on almost all passenger vehicles and light trucks. Hydraulic brakes use brake fluid to transmit force when the brakes are applied. Since brake fluid cannot be compressed, force is transmitted immediately and directly at each wheel when you press the brake pedal.

Air brake systems are used on large commercial vehicles because they can develop and transmit high mechanical forces over great distances using simple components and connections. Air brake systems use compressed air, which is stored in tanks, to produce the force that applies the brakes at each wheel.

When you press the brake pedal, compressed air must travel from one part of the system to another. Special valves make sure that the air moves through the system as quickly as possible; however, there is a split-second delay in brake reaction from the moment you apply or release the brake pedal.

This split-second delay in brake reaction occurs in all air brake systems.


https://www.ontario.ca/document/official-air-brake-handbook/vehicle-braking-systems

 

Yes, it is normal. All air break systems have lag

 

Remember, the pedal breaks both the tractor and the trailer. The trolley break only breaks the trailer

 

I think you guys missed the part where hes saying it happens if he hits the brake once and then if he hits the brake a second time it doesnt lag. Air is released you release the brake pedal. So not understanding you guys theory of having to pump your brakes once so they work for you the second time instant. Brakes work the same on first punch as they do on the second punch. There is no difference.

 

Depends how much time elapsed between releasing the pedal and applying it again. Takes air a little time to exhaust and it takes the chambers a little bit to fully retract as well.

 

10-4 but unless this is the first time driving the truck on the road, theres obviously a noticeable foot valve issue that made him quickly notice this and ask question on here. whereas all the other trucks he has driven or the truck now didnt have the issue before hand

 

Ontario and Quebec air brakes operate with zero lag if you go by the 3 to 5 feet following distance at 65 mph many use over there . Accident rates say different though.

 

Trolley hits harder. It brakes harder with initial than my foot pedal does.