I see road signs in some towns "End of Brake Retarding Zone".


What does this mean?

As I live in the UK but do know a bit about roads Think about the Location of the Sign Is it situated at the end of a Steep downgrade?

All we get as a warning at the Top of the Hill is Low Gear Now under a triangular sign with a "!" meaning Hazard (Unspecified) with a Plate underneath it with an instruction or information about the Hazard

Example here (Pic)
On Uk stick shifts slowing down and Changing down a gear and use brakes is Usually the Best Way to get through the Hazard
Auto boxes I have not tried but I should be select Low and use Lots of Brakes (Not as Much engine braking) I see US Some Autoboxes(just googled it) Have some manual or auto control which applies even more enging braking ..The must be the Retardation device the sign refers to?
I'd find them a Dirty device Because to run an engine in that way the Fuel mix would be set richer than Normal...Makes a Hash of Pollution Laws ...Diesels are the worst!

Wheres DodgeCity? He I believe runs a truck
and He may Know how the Brake Help system works?


PS Unlikely many of you Have driven Ridden a 2 stroke Car or Motor cycle The only way to Utilise the Engine on this setup is to brake Hard and Go down 2 gears if need be? Engine Braking is only noticeable at very low road speeds Though on the Plus side the Powerband accelerating Is full power and Torque almost to the red line..All other engines Peak Torque at 2/3rds through the Flat Power band this is Best RPM speed to get maximum engine braking Though I think with The Power assisted Engine brake there is a Choke flap shut in the Fuel system Thus Putting a lot of extra demand on the Engine Like a cold running device in Winter Richening the Fuel mixture ?

Bet I'm not too far off with my Theory/explanation

The term use to be “Jake Brake” until the company the owns the phrase “Jake Brake” went to court and had cease and desist order granted. All cities and towns had to change their signs to Brake Retarders.

OK, now what is a brake retarder? It is a way that the diesel engine is turned in to an air compressor. When the operator wishes to slow down, he activated the brake retarder to assist him in braking. In simple terms, this takes the forward momentum and turns the engine over with the fuel injectors closed. Much like down shifting is used to help slow down. As the piston comes up to fire, there is no fuel to fire and just compress the air. As the piston comes around, the exhaust port opens and you here the popping of this compress are escaping.

The reason behind having those signs, brake retarders can be noisy. Cities and town put up those signs "No Brake Retarders" when you enter their "Quite Zone" and an "End" sign when you leave.

Brake retarders are not nosiy. It is only when the trucker thinks he can get better power or mileage or just wants to sound cool, he removes baffles from his muffler or changes it out completely then it becomes noisy. It will scare the crap out of you if you're sitting at a light and a truck comes up and hits his "Brake Retarder".

Here it is, right from the horse's mouth.

Probably more information then you wanted to know.

WOW
Do StateSide Lorries,buses and HGVs Also have Air brake compressors fitted? (as do Many Locomotives ) Some after Braking or idling, Start charging the Brake vacuum up And if there is an air leak or Pressure Fault,it runs constantly Gulping air or Blowing off!
Best examples are The Subway trains as its all electric,and Frequent Stops
NOTE On the Railways the Vacuum/Air brake Keeps the Brakes off so any Pressure drop/increase applies the Brakes!

Yes, all large trucks, buses and subway trains have air brakes. Some smaller trucks have "Vacuum Assisted" brake similar to cars.

It is still a mystery to me exactly how they air brakes work. I do hear the air compressor come on then go off at times.

The one thing I am sure of is the "Break Away" system. If the trailer breaks away from the tractor part, we call them tracker-trailer state side, the trailer brakes will be applied to stop it from rolling on. I even have that on my camper trailer except it is electric and requires a 12 volt battery on the trailer.

BTW, what is HGV?

HGV = Heavy Goods Vehicle
In the UK thats Anything over 30CWT
There is also a LGV(Light Goods) class For small Vans and Pickups...used to be classed with cars But The Governent wanted to make money about these Vans so they are Sometimes another driving test
Even I am confused on this
PSVs are Buses (Public service vehicles) and there are several driving tests.

Easiest way into HGV or PSV is to get a Military Driving Licence And they waive you into Really heavy Machinery
Best the ordinary UK motorist can do is Drive a LGV or take a PSV test with their Licence otherwise have to Go up the Grades and spent 1000's of Pounds and several years To become a HGV class 1(PSV= HGV class 3 but have to take another test to gain that tag )

PS Just to make things a wee bit harder There are the "Special Hazard" qualifications too (to be added)

Vacuum Failure in the Master cylinder of a car is indicated By the Brake Pedal going rigid and No Brakes. Switch off to stop and use Hand brake sparingly!
Goes to the Floor and Need Pumping (for some braking effort) is Brake Fluid related

quote:

Originally posted by Walks On Water:
It is still a mystery to me exactly how they air brakes work. I do hear the air compressor come on then go off at times.

Modern air-brakes on large vehicles work like this:

The friction material, (pads/shoes), are held tightly against the brake drums or brake rotors by a heavy springs. Compressed air is produced by a compressor driven by the vehicles engine, and this air is stored in tanks. When the vehicle is ready to move, a valve opens and lets the compressed air move into the brake system and pushes the pads/shoes away from the drums/rotors. When the brakes are applied, another valve opens and the compressed air is bled out of the system at a rate related to pedal force, allowing the springs to push the friction against the braking surfaces. So since the air actually holds the brakes open, any accidental loss of air will result in a stopped truck and not a runaway truck.

So you're saying the only thing stopping that big reg with a full 53 foot trailer is springs. OMG.

quote:

Originally posted by Walks On Water:
So you're saying the only thing stopping that big reg with a full 53 foot trailer is springs. OMG.

Eh? No, they all have air brakes !

The compressed air RELEASES the brakes, the springs press the brake pads against the drums or rotors. The loss of air results in the application of the full braking ability - a "fail-safe" method.

You know, now that all this has come to light, I remember working with a trucker in my youth.

We climbed in the cab and he started the engine. Then we sat there. When I ask why we were just sitting there, he replied he was waiting for the air pressure to come up. He said "this truck won't move an inch unless we have air pressure.

You see how one little conversation can bring back 40 year old memories.

Thanks for the data bank up date.

quote:

Originally posted by Sherasi:
I see road signs in some towns "End of Brake Retarding Zone".


What does this mean?

Seein as how retard means slow, then it would more than likely mean that you do not hove to slow down anymore

quote:

Originally posted by Sherasi:
I see road signs in some towns "End of Brake Retarding Zone".


What does this mean?

this means that trucks can use there engine brake,s now. the engine brake is like plugging the exhaust pipe. they are quite loud on some of the rigs. this is the only way that a diesel engine can slow down when descending a steep grade. unlike a gas engine witch use,s compression to slow down a diesel engine will in fact go faster till it disintegrates it,s self. if you go down hill and get in front of it DO NOT HIT your brakes cause it CAN NOT STOP.
i get this all the time have hit two cars in three years. they where lucky they did not die.