Downgrades without jake/engine brakes

Translation... I'm a cheap SOB! And I don't care bout your safety!!

 

Why aren't you using your jakes?

 

They used to teach 'light steady pressure' of the brakes down hills. 30 psi is not light pressure, in fact it will bring the truck to a dead stop (providing the brakes are decent). I use the proper gear and snub braking, often less than 10 psi for the 5 seconds of brake application to slow the truck down. Today's video--

 

Ah ok. Then go with the 2nd post here.

 

Here is your answer it help a lot if you have the gauge that tells you how much brake pressure you apply to the brakes.

It's 10 psi or less of brake pressure. All the way down the hill. The reason is because the drums can dissipate that much heat. If you apply more pressure you generating more heat then the drums can release. So they keep getting hotter, that make them expand more. So you apply more brake pressure and they get hotter and hotter. Till you brakes can't touch the drum anymore and you got no brakes.

That's why you use 10psi or less and you can ride the brakes all day and they won't over heat. You use the bakes to get you down a hill. You use a Jake/engine bake to get you down the hill faster. Because using 10 psi or less and a Jake brake you can go faster down hill.

If you use the stab braking that's ok in the summer but not so good in the winter. That why I was tough to use light steady pressure 10 psi or less. That also how you now if your in the correct gear and speed for any load or hill. If you can hold the truck back with 10psi or less. I'm guessing you don't have that dash gauge. Companies that don't go west much don't put them in their trucks.

 

I can't seem to find the link. University of Michigan did a study of different braking methods going down a sustained grade. They checked for heat on the brake pads. The methods were Stab Braking (maximum braking periodically), Snub Braking (applying 20 psi with one second braking for every six seconds not braking), and Continuous Braking (with 10-20 psi). There was no difference in brake heat between the methods.

I don't recall all the exact details of the experiment, but it surprised me that they found all methods equally effective. I have driven quite a few trucks with no Jakes recently. In that situation on long grades I have tended to go for continuous braking with periods of heavier braking and then let it go for a while. It seems much smoother than trying to have larger variations of speed, and it is much better if in slick conditions or on dirt roads going down grades greater than 20%.

 

@scottied67

In the Youtube video, @ 5min mark, you were at 1800RPM, you touched the brakes for 5 sec's (finger count) and dropped engine speed to 1600RPM.

Is that what's called stabbing the brakes? <----LOL... @Lepton1 answered it as I was typing.

I suppose you doing that so as not to overheat the brakes?

I wish you could do a read out of the air pressure readings too next time.

 

@nax, the 5 second thing is called Snub braking. A lot of people confuse it and called it Stab braking.

 

Without starting that whole debate again , it is safe to say :" DO NOT use the steady braking methode if you have disk brakes on either truck or trailer."
In that scenario bad things will happen.