Share Pics of People Hauling or Towing Something Wrong

[paulfun9]

Applying: As the brakes are applied, air pressure decreases. As the amount of air decreases, the valve allows air back into the reservoir tanks, while the brakes move to the applied position

 

[4570Man]

I tested the spring brakes on my F-750 today. I was towing an 80 trackhoe so the gross weight was around 40,000. I was rolling down a fairly steep hill going about 15mph. I pulled the spring brake release and it rolled about 50 feet before stopping. Also keep in mind my trailer is electric brakes so it was doing nothing in this test and there’s no springs on the front so it was also doing nothing. So I’d say to only have one axel doing the work that’s a fair amount of stopping power. That one axel might not stop you going 60 mph but if you had the trailer helping it definitely would. But this whole thing is irrelevant considering the service brakes on the truck that wreaked failed from heat not lack of applying.

 

[paulfun9]

I know you understand the working of them but for others consider you have multiple axels with spring brakes/ emergency brakes on both the truck and trailer.
For you how far would you think you would travel using the brake pedal and no trailer brakes for comparrison.
Also are you set up with anti lock brakes?

 

[4570Man]

I know you understand the working of them but for others consider you have multiple axels with spring brakes/ emergency brakes on both the truck and trailer.
For you how far would you think you would travel using the brake pedal and no trailer brakes for comparrison.
Also are you set up with anti lock brakes?

Assuming they were functioning properly and not burned out you would be able to stop pretty well using just the tractor service brakes or just the spring brakes on all 4 axels. I mean you won’t set any short stop records but easily good enough to safely stop the rig. My truck was built later than the 90s when they mandated them so presumably it has ABS but I’ve never had it come on.

 

[paulfun9]

Assuming they were functioning properly and not burned out you would be able to stop pretty well using just the tractor service brakes or just the spring brakes on all 4 axels. I mean you won’t set any short stop records but easily good enough to safely stop the rig. My truck was built later than the 90s when they mandated them so presumably it has ABS but I’ve never had it come on.

I think your ABS may have worked during your test today.

 

[4570Man]

I think your ABS may have worked during your test today.

The wheels never locked. Like someone else predicted the springs weren’t strong enough to lock them under load. But the spring brakes are still extremely good compared to other options for parking/emergency brakes. I’d like to trade my electric brake trailer for an air trailer. The electric brakes aren’t that great and they don’t have any parking function.

 

[Travelover]

110 years was too high. I don't think he deserved a day over 90.

 

[duramaxsky]

The spring valves will lock the whole truck down tight and the wheels skid.

No they won't not even empty.

 

[duramaxsky]

Ever blow an air line? What do you think happens?

The brakes get hot and slow you down a little for a short while.

 

[4570Man]

No they won't not even empty.

They will usually look the wheels hard enough to skid if it’s already stopped and something else is dragging it. In any case locking the spring brakes on a moving truck and trailer will quickly bring it to a stop assuming they still have full function and aren’t burned out.