Thread: Engine Brakes

I use the engine braking all the time in the 130. Catches people out all the time when I just slow without brake lights while they are crawling under the rear.

Had brake loss twice in my life once on the clide Mtn. We overtook a small truck on a blind corner while trying to stop the car. Lots of fun that one.
Second time was brake failure so I gunned it through an intersection just missed being t boned but it was better than rolling him. took me 2 blocks to pull the car up. Worst thing was I had new pads, calipers, rotors and fluid in the car and was on my way to fit it all. Turned out one of the lines had ruptured and the hand brake didn't work.

In low range normaly I find the ring is going a lot slower down hill than expected at I ofter have to accelerate.

Gday

Since fitting the snorkel Im convinced the engine brakes have improved? Am I imagining things or could this be possible

Thanks

Originally Posted by longreach

Hi ,I drive a B double most days ,carting loads in excess of 50 tonnes,I travel down the toowoomba range nearly every day,the engine in my truck is a caterpillar ,I can come down the range in second intermediate ,in a eighteen speed fuller box,and never have to touch my foot brakes,the engine brake can hold me back all the way down the range,at the bottom my brakes are cold as...that's how good engine brakes are,best thing ever invented.........In trucks thy are a god send...keith

On a proper truck with a Caterpillar the engine breaking will be in the engine where the exhaust is retained in the cylinders by reducing the time the exhaust valves are kept open. This is very different to an exhaust gate style where a gate is added just after the manifold. The Cat engine is designed for them and the engine retarding is in the cylinder, not some aftermarket system adding extra pressure in components that were never designed to hold pressure.

Your service brakes are also full air where your engine braking will have no detrimental on your foot brakes. Not so with engine inlet generated vacuum boosted foot brakes, where exhaust gate engine brakes can have a major impact at the worst possible time.

in a proper truck....

it doesnt have to have a cat donk (tho I do like them)

you have either a jake brake which can be added to almost any diesel engine providing your willing to pay for the adaptoin of the add in bits that make it work to suit your particular engine.

or you can have a dynotard like whats in the Mack engines which has a funky setup with double profile on the exhaust cam and a hydraulically extendable push rod to make it work.


both do the same thing.

crack the exhaust valve open near the top of the compression stroke to dump the compressed air out the exhaust. this has a secondary bounus if your turbo charged.... it spins up the turbo which then pushes more air into engine like it was supposed to do as opposed to the turbo slowing down which is what happens with a post engine flap valve (it generally wont come to a complete stop)


as for the vac running out.. since most diesels dont have a vac generator built onto the intake that requires the normal flow of air to work but rely on some form of mechanical pump you're laughing.