TT Weight limits: theory and reality
There are a ton of threads here regarding the proper matching of TV and TT. Based on what I learned here, I made a very expensive decision to upgrade my brand new 1/2 ton to a 1 ton TV so that I would...
Forum Discussion
Braking is a tricky subject. My experience is with sports cars, not trucks. To safely operate my car (a 370Z at the time,now I have a Mustang) at track speeds and providing the required deceleration to make the turns, one has to "tune" the brakes. I used a sport racing brake pad. These pads are a lot more aggressive and generate more friction and heat. That has nothing to do with my vehicle weight. The tires have a specific ability to hold on to the pavement. This value varies by tire type. The summer tires I used on the track were close to slicks and had enormous grab. I suspect the same is true of our trucks. The combination of brake pads/discs and tires determine the time it will take to stop at a given speed.
There is one more factor that can spell disaster: heat. Aggressive or long braking generates a lot of heat. My 370Z did not have brake vents (Nissan really blew that) and the brakes could get so hot that they boiled the brake fluid. When that happens you have no braking whatsoever. Total failure. Road and Track magazine actually crashed a 370Z because the brakes failed during a test. Each time I came off the track you could smell the burning brake pad composition.
We know the danger of long, downhill braking. The brakes can overheat. Here is something that you should consider. The trucks use a standard DOT brake fluid. I don't know the rating offhand, but probably DOT 3 or 2. That rating offers some indication of the boiling point of the fluid. There is a big difference in boiling point between brands of brake fluid. Be sure to research this. Good brake fluid will cost a lot more than the junk your dealer or local parts shop has on the shelf. It's a small investment to get the good stuff.
That's only part of the story. The brake lines between the frame and the wheels are usually rubber. That rubber lets moisture get into the brake fluid. Water in the brake fluid lowers the boiling point.
In my sports car I used a special racing brake fluid and replaced the rubber lines with steel-mesh-jacketed teflon. Those lines didn't let any water in. Nonetheless, for safety, brake fluid needs to be changed regularly. Since we tow, which puts a bigger load on the brakes, they will probably operate hotter than an unloaded truck's. It's money well spent to replace the brake fluid ever couple of years. If you can keep the boiling point over 400 deg F, you get that much more margin before the fluid will boil.
There is one more factor that can spell disaster: heat. Aggressive or long braking generates a lot of heat. My 370Z did not have brake vents (Nissan really blew that) and the brakes could get so hot that they boiled the brake fluid. When that happens you have no braking whatsoever. Total failure. Road and Track magazine actually crashed a 370Z because the brakes failed during a test. Each time I came off the track you could smell the burning brake pad composition.
We know the danger of long, downhill braking. The brakes can overheat. Here is something that you should consider. The trucks use a standard DOT brake fluid. I don't know the rating offhand, but probably DOT 3 or 2. That rating offers some indication of the boiling point of the fluid. There is a big difference in boiling point between brands of brake fluid. Be sure to research this. Good brake fluid will cost a lot more than the junk your dealer or local parts shop has on the shelf. It's a small investment to get the good stuff.
That's only part of the story. The brake lines between the frame and the wheels are usually rubber. That rubber lets moisture get into the brake fluid. Water in the brake fluid lowers the boiling point.
In my sports car I used a special racing brake fluid and replaced the rubber lines with steel-mesh-jacketed teflon. Those lines didn't let any water in. Nonetheless, for safety, brake fluid needs to be changed regularly. Since we tow, which puts a bigger load on the brakes, they will probably operate hotter than an unloaded truck's. It's money well spent to replace the brake fluid ever couple of years. If you can keep the boiling point over 400 deg F, you get that much more margin before the fluid will boil.
