The Stovebolt Site Forums The Shop Area Driveline cable emergency brakes vrs propeller shaft brake

Hi guys,
I Want your opinion about to use the emergency brake located a the end of the gear box in my 1952 3/4ton chevy truck. As you know it was used on 1 ton trucks, but what happen if I select this option and not the cable one. Which one could be better?
thanks, Alfonso

On the driveshaft brake, it locks on good, maybe too good to stop a moving truck but holds well for parking. I could see the rear wheels locking up if you weren't used to the self-energizing action of that system. Also, if you had to jack up a rear wheel, it could roll since the brake is on the shaft not at each wheel. With the rear wheels style brake, you apply the brakes as if they would using the hydraulic system to stop a moving vehicle. Also, when adjusted properly, they lock both rear wheels up so changing a tire is much safer when applied.
That's my take on it,
Scott

I have thought about doing this as well but it would require a new driveline to replace the ball/tube/carrier set-up. The 3/4 ton E-brake parts at least the cables, clevis's etc are hard to locate if they are missing, as to operability and adjustment it looks easier. I would be curious to see what other's think.

Thanks guys,
Brad, my case is inverse than you; when I bought the truck, it does not coming with the complete emergency system on the wheels, the last owner had the gear box with the driveshaft brake and gave to me as part of the deal.
I like the Scott´s comments, I think if the major problem is to jack up a rear wheel, I would like to take the risk.
anyway guys I like to see other opinions
Thanks, Alfonso

Some time back I had a 57 one ton. It had the brake on the trans. I think this is cool. I don't know which is better. There is something cool about setting the parking brake with a handle.

I really like the transmission mounted parking brake that someone swapped into my 52 1 ton.
It holds really really well on any incline, no hesitation. I found it usable as an emergency brake with no problems, just takes a light application to slow down a lot.

I don't know about the wheel mounted parking brake, with a transmission mounted one that works so well I'll never bother to find out either...

Yes jacking a rear wheel up renders the driveline brake useless, but when (if ever) do you absolutely have to change a wheel on hill, and why can't you use wheel chocks like you know you should no matter what brake you have?

Grigg

Not to mention what a PIA the brake cables are. They are hard to find usually, lock up after a while and require a fair amount of maintenance.

On my 2 48 1.5 tons, I just used unsheathed cable and ran them back to the backing plates. Nothing more to ever stick and they work great.
Scott

That is the way my 52 is. I do it to my 46 if they freeze up again.

Both types will hold a truck. However the cable type have more braking power if your service brakes fail. That is if they are properly adjusted. 50 years ago very few parking brakes worked. Either someone had forgot to release them or they were never adjusted. Almost everyone simply put them in 1st gear to park.

Ahh, I don't know about these, but, both my old Land-Rovers had transmission brakes. They were great off road, as they slowed down both axels. If however, the trans leaked, the pads would become soaked, and there was no emergency brake. I have cable pull on my 1 ton, and really like them.

I'm not an engineer either, but I learned to drive in the 50's when both systems were around, the rear wheel brakes did a better job than the drive shaft parking brake. It was common to have brakes fail. And I remember several times trying to stop with the parking brake. Possibly the difference was that transmissions always leaked a little and the linings were oily. The best strategy when the brakes failed was to steer around what ever you were braking for.

Is there anything that says you can't have BOTH systems? They work independently of each other and you could have double redundancy in some situations.

I have a SM420 with the shaft brake assembly and I intend to put it on in working order, along with the existing pedal assembly (I will need cables) unless there is a reason why they can't co-exist.