Community Forums

Peddler · 11-18-2011, 05:31 AM

In various threads debating the preference of electric versus surge brakes on dollies, there have been some who claim that surge brakes drag and overheat on prolonged downhill runs. Does anyone have actual knowledge of this being a problem?
I am looking for a dolly and like the idea of surge brakes as I could use any vehicle to pull it without installing a controller. I already own a controller that would be installed in the MH so added cost of the electric brake is not a factor.

ahicks · 11-18-2011, 10:20 AM

In most surge brake systems there's a spring that must be overcome prior to the brake being actuated - just for that situation, as well as possibly some backing scenarios. I've heard those same arguments as well, but I don't think they take this spring into account.

bearaboo · 11-18-2011, 01:44 PM

I have a Master Tow with surge brakes. Never had any problems with brakes dragging on steep hills.

Gma-n-Gpa · 11-18-2011, 01:52 PM

Interesting question - i have a master tow as well and have not noticed any drag. Have surge brakes on my Ranger and again have not noticed drag. I wonder how you would test to verify??

Peddler · 11-18-2011, 01:57 PM

Quote:

Originally Posted by Gma-n-Gpa

Interesting question - i have a master tow as well and have not noticed any drag. Have surge brakes on my Ranger and again have not noticed drag. I wonder how you would test to verify??

The only way I would know, and the only thing that actually matters is - are the brakes hot at the bottom of the hill?

My choice will probably be a Master Tow. Looks like the best quality while staying within the added weight limit I want to stay under. (5-600 pounds)

Hitch rated at 5000, GCWR fine, TOAD weight ~3800 pounds, gives me 6-700 cushion.

wa8yxm · 11-18-2011, 02:31 PM

One thing I will comment on.. Unless you have a feedback system (Such as an indicator light on the dash of the towed you can see in your rear view camera tied to the brake light switch) you would not notice drag from the surge brakes going down hill.. Since the surge brake is activated by the towed pressing against the motor home... The "Drag" of the surge brakes can NEVER be enough to notice in the motor home. NEVER. without sensors to measure the force on the tow bar. Or an infra-red pyrometer measurement of the wheels on the towed post down hill.

Now, how strong that spring is.. I don't know, If it's strong enough then a 7 percent grade wont' drag 'em down.

docj · 11-18-2011, 02:47 PM

Surge brakes are not designed to be applied just because a vehicle is going downhill. They are applied when the vehicle towing the trailer (or ReadyBrake-equipped toad) applies its brakes. The surge-brake mechanism senses the deceleration of the towing vehicle and applies the toad brakes. It is very difficult to detect the application of the toad brakes because they are only on when you are already in the process of braking. I have an indicator light in the MH that shows when the toad's brakes are being applied, otherwise I honestly would not be able to tell.

CD · 11-18-2011, 07:49 PM

Quote:

Originally Posted by Peddler

In various threads debating the preference of electric versus surge brakes on dollies, there have been some who claim that surge brakes drag and overheat on prolonged downhill runs. Does anyone have actual knowledge of this being a problem?
I am looking for a dolly and like the idea of surge brakes as I could use any vehicle to pull it without installing a controller. I already own a controller that would be installed in the MH so added cost of the electric brake is not a factor.

This may not help answer your question but many years ago when I towed a rental TT (15') with a Ford car I felt the car was doing most of the braking , especially going down hill. I learned that by jabbing the brakes and easing off the car brakes, the trailer barkes would stay applied until I released the car brakes. I did a lot of this to save the car brakes.(remember I had a rental TT).

wa8yxm · 11-18-2011, 08:12 PM

Quote:

Originally Posted by docj

Surge brakes are not designed to be applied just because a vehicle is going downhill. They are applied when the vehicle towing the trailer (or ReadyBrake-equipped toad) applies its brakes. The surge-brake mechanism senses the deceleration of the towing vehicle and applies the toad brakes. It is very difficult to detect the application of the toad brakes because they are only on when you are already in the process of braking. I have an indicator light in the MH that shows when the toad's brakes are being applied, otherwise I honestly would not be able to tell.

Actually Doc, the surge brake systems sense when the towed is pushing on the towing vehicle. I assume your indicator shows that just going down hills is NOT enough to engage the towed brakes... I believe this answers the OP's question (mine too for that matter) Thanks.

There are several systems which can sense "Deceleration" but all of them will also sense going down hill.. The simple reason is that going down hill (Less you use Georgia Overdrive) you are decelerating. (or at least holding the vehicle back with engine braking) (For those not familiar with the term Georgia Overdrive is coasting down hill in neutral,,, Illegal in Georgia)

SOME systems.. US-gear, and Invisi-Brake for example. also sense if the brake pedal on the towing vehicle is depressed.. Surge brakes do not do this, neither do "Box" systems like Brake Buddy.

Some systems such as M&G or Air Force one actually operate off the Towing vehicle and thus again sense if you are pressing the pedal.

Mr_D · 11-18-2011, 10:42 PM

Quote:

Originally Posted by Peddler

In various threads debating the preference of electric versus surge brakes on dollies, there have been some who claim that surge brakes drag and overheat on prolonged downhill runs. Does anyone have actual knowledge of this being a problem?
I am looking for a dolly and like the idea of surge brakes as I could use any vehicle to pull it without installing a controller. I already own a controller that would be installed in the MH so added cost of the electric brake is not a factor.

We had a locally built dolly with surge brakes, we came out of Jackson Hole to the west. 10% up and 10% down. Later I found that the brakes were burned and the linings were falling apart. I bought all new backing plates complete with the hyd cyls and shoes. Not much more cost that way.
We now have a Demco KK460 with surge brakes. It didn't have any way to stop the brakes from energizing when the exhaust brake was engaged. It was supposed to have an extra spring unit installed but ours came without it. They sent one at no cost. Seems to be working fine now although I'm not using the dolly to tow now.