has anyone ever overheated surge brakes?

[shoestring]

i just bought a used boat, 3500# boat, tandem axle with disc brakes on one axle, i havent towed it home yet but i was wondering. i will be going down a 6 to 7% grade for about 15 miles. this means 2nd gear (auto) about 35 to 45 mph. when i was checking out the trailer i pushed in on the tongue, i was surprised how easy it was. so now i'm invisioning myself towing down a long grade, 2nd gear for engine braking and this trailer is going to have the brakes applied to some extent for 14 or 15 miles. lots of boats are towed up and down this grade without problems but it sure sounds like something is going to get awful hot back there. i get a little edgy when things that aren't supposed to smoke, start smoking! seems like there should be some spring tension in the tongue so the trailer brakes don't come on unless you are pushing on the brake pedal. with this setup it looks like engine braking alone will apply the trailer brakes.

[Pez Vela]

Yes I have, under circumstances similar to those you describe (Santa Rosalia grade in Baja). As a matter of fact, I've done it many times.

My approach: make sure the brakes are in excellent shape, as well as the hubs, bearings and seals. Grease the bearings/hubs well, and don't hesitate to pull over on the grade when convenient to check them, add grease if necessary, and allow things to cool down a bit. MOST IMPORTANT: start driving on the grade slowly, very slowly, and keep it that way. Don't be in a hurry and you'll be fine.

[tractoman]

Did you check the fluid in the master cylinder of the trailer? The actuator should not move that easily if the brakes are adjusted properly, the fluid level is correct and they are bled well. On mine it only moves about 1/8-1/4 inch before there is pretty noticeable resistance from the master cylinder.

[shoestring]

Did you check the fluid in the master cylinder of the trailer? The actuator should not move that easily if the brakes are adjusted properly, the fluid level is correct and they are bled well. On mine it only moves about 1/8-1/4 inch before there is pretty noticeable resistance from the master cylinder.

no i didn't, it moved about 1/2" before it felt solid like it hit the master cyl. my concern is more about how much force it takes to apply the brakes. i would rather the brakes not come on and let engine braking do most of the speed control. and have the trailer brakes come on when i apply the tow vehicle brakes. i have not towed the boat at all yet so i maybe premature in my concern. if i can apply the trailer brakes by pushing in on the tongue by hand, i'm afraid i'm going to smoke them on a long down grade.

[tractoman]

Do check it. That much movement may mean the brakes are not to well adjusted or low on fluid. I am sure you could find a way to keep the brakes from dragging too much down the hill but the TV brakes would be the concern even if you are in gear. You really want to have functional brakes when you need them.

[smokeonthewater]

15 mile grade with surge brakes= 3x5 mile segments with two cool down sessions on side of road or at exit if needed.... just one more reason I like elec brakes...... oops did I start THAT again ... lol

[bruceb58]

And I like electric/hydraulic for the same reason.

What you are describing is one of the drawbacks of surge brakes. Surge brakes are self compensating. If they come on too hard like you think, then the actuator gets pulled back and the brakes are removed. What happen is that they come on enough to still have a certain force on the master cylinder and is exactly what you describe.

Personally, I think you will be fine as long as you don't have the stainless Tie Down brakes. They are horrible and I warped a rotor on those. If yours are vented you should be fine.

[bruceb58]

Do check it. That much movement may mean the brakes are not to well adjusted.

He has disk brakes so not an issue.

[q5ka]

I am with smoke on this one. I also like electric (I only run on fresh water) due to I control the brakes, not inertia or gravity. Just turn on exhaust brake, let the diesel slow me down, and tap brake as needed to maintain safe speed. If trailer starts swaying, reach down and tap the controller to activate trailer brakes. If I want the trailer to brake harder or lighter, I adjust that from cab. For those that hate to adjust your controllers when empty, if you get into a routine for launching and retreiving your boats, that would be part of it.

[bruceb58]

Well...the op has disk brakes. Would be silly to take those brakes off and put on electric. He is going to be fine with what he has. He only has 3500#.

[cribber]

I agree he should be fine and pull over after 5 miles or so, give everything a once over and if nothing is over heated continue on the rest of the way. But really, with disc brakes the likelihood of overheating is pretty slim. Just maintain a steady speed.

[jeeperman]

If you really wanted to and it has a solenoid that activates with the reverse lights, you could use that same solenoid to disable the brakes whenever you desire.
With some creative wiring you could turn that solenoid on and off from inside the cab while under way.
Via a new switch in the cab wired into the cargo light or the backup lights circuit.
Or independent circuit to the solenoid.

[bruceb58]

If you really wanted to and it has a solenoid that activates with the reverse lights, you could use that same solenoid to disable the brakes whenever you desire.
With some creative wiring you could turn that solenoid on and off from inside the cab while under way.
Via a new switch in the cab wired into the cargo light or the backup lights circuit.
Or independent circuit to the solenoid.

Except when you have it disabled and someone cuts in front of you. Seems to me that would be a recipe for disaster.

[jeeperman]

Except when you have it disabled and someone cuts in front of you. Seems to me that would be a recipe for disaster.

And so too you could wire it into the brake light circuit to cut power to the solenoid if the brake pedal is touched. In case you forget to switch back to normal operation.
Like cruise contol.

[bruceb58]

That could work. You would have to have the setup that dumped any fluid behond the valve back into the master cylinder. Most of these aren't set up that way so if the valve engages, any pressure betwen the valve and the brakes keeps any pressure that is in there.

[Randybeall]

That could work. You would have to have the setup that dumped any fluid behond the valve back into the master cylinder. Most of these aren't set up that way so if the valve engages, any pressure betwen the valve and the brakes keeps any pressure that is in there.

Acutally, some systems solonoid valve is a one way which shuts off input from the mastercylinder while allowing free flow from the brakes to the resivour. I have not checked in several years but the state of Colorado used to require that surge brakes have a lock out to prevent just such a problem. They do have a few mountains there.

[shoestring]

If you really wanted to and it has a solenoid that activates with the reverse lights, you could use that same solenoid to disable the brakes whenever you desire.
With some creative wiring you could turn that solenoid on and off from inside the cab while under way.
Via a new switch in the cab wired into the cargo light or the backup lights circuit.
Or independent circuit to the solenoid.

thanks, but i'll pass on that one. an accident that results in a fatality, disabling your trailer brakes could land you in the pokey for manslaughter

[gcope63]

I bought a new chevrolet truck in '04 and the first time out learned about the tow/haul mode.. Come down a 8 mile 6% percent grade with the tow mode and thought how nice this feature was until I stopped at the bottom of the hill at a gas station and noticed the hubs that had brakes were smoking! Both of the bearing buddies were all of the way out and there was grease all over the wheels! After it cooled down everything went back to normal and after greasing up the hubs I was good to go.. Learned from then on not to use the tow/haul mode going down hills!!

Gary

[bruceb58]

I bought a new chevrolet truck in '04 and the first time out learned about the tow/haul mode.. Come down a 8 mile 6% percent grade with the tow mode and thought how nice this feature was until I stopped at the bottom of the hill at a gas station and noticed the hubs that had brakes were smoking! Both of the bearing buddies were all of the way out and there was grease all over the wheels! After it cooled down everything went back to normal and after greasing up the hubs I was good to go.. Learned from then on not to use the tow/haul mode going down hills!!

Gary

The tow/haul mode only changes shift points. Has nothing to do with engine braking. Might want to read the manual.

[gcope63]

Actually on the Allison it will downshift when you tap the brake which causes the surge brakes to engage. If you don't accelerate it will stay downshifted. This is great if you have electric brakes which only engage when the brake pedal is depressed.. This is what caused the overheating. Don't need to read any manual for that.

[bruceb58]

Sorry about that. I was not thinking that you could have possibly had the Allison. I am very familiar with those transmissions and they do as you say.