Surge drums PLUS elect/hydraulic disks

[ewk]

Great forum -- lots of good tips and shared experiences. So...interesting question for which I've gotten some interesting answers -- what do you think about this. 20.5 ft bow rider on tandem axle trailer -- total weight about 5500 lbs. Trailer is factory equipped with surge drum brakes on the rear axle. I want to add an electric over hydraulic supplied disk brake system. I was going to replace the drums with the disks but several (supposedly knowledgeable) people have suggested simply adding the disks to the front axle and replumbing the surge coupler with a manual three way valve. The three way would function like a backup solenoid in that in one position it would dump back into the master cylinder (no drum brakes) and in the other position the surge drums would function. The ele/hyd would, of course, be functional whenever hooked up. The logic is that the electronics in ele/hyd system or in the tow vehicle controller can fail and I will always have the surge as backup. And, family members have a range of vehicles some with and some without in-cab controllers and 7 pin receptacles. I tow long distances (500 miles +) and in the mountains of upstate NY. Any thoughts or advice?

 

[tommays]

Re: Surge drums PLUS elect/hydraulic disks

The only down side to the really good controlers is there abilty to lock up the Trailer wheels if the setting gets cranked up to high in the Cab


Which will eather flat spot the tires ( i have done on a travel trailer ) its pretty hard to dial down the force in a panic stop if you run into a sudden slipery spot


The surge couppler makes it allmost inpossable to lock trailer wheels

Tommays

 

[bruceb58]

Re: Surge drums PLUS elect/hydraulic disks

I think bad idea all the way around.

First off, you can't use a surge brake master cylinder for disc brakes that is designed for drum brakes without first rupturing/removing the residual valve on the master cylinder. This valve puts a small amout of pressure on the drum brake seals. On disc brakes, this extra pressure will cause them to drag and overheat.

Second is that each type of brake requires a different amount of pressure for a given brake force. You will have one set of brakes doing more of the work than the other set.

Maybe I read your post wrong and the two systems have totally seperate hydraulic sytems from each other.

What disc brake system are you purchasing?

I also have the electric/hydraulic system with 4 wheel disc brakes on my trailer. I have the Brakerite elect/hydraulic unit and Kodiak brakes on mine.

 

[ewk]

Re: Surge drums PLUS elect/hydraulic disks

Hello Bruceb58 -- Yes, there would be two separate systems -- the factory surge drums changed only with the addition of a three-way valve to enable or disable the surge brakes as desired (effectively, a manual reverse lockout solenoid) and a new electric/hydraulic disk on what is now the idler axle (front axle). I'm considering the Brakerite with Kodiaks. It wouldn't be a big deal to replace the drums with an additional set of disks (and that is what I originally intended) but a number of "old timers" have questioned why I would want to do so. They're point is that the disks will do most of the braking (if the controller is set properly for the conditions) and the surge will only function if I ever need the extra braking power (trailer creeping up on truck even though the disks are braking). They also point out that I should remove the surge coupler if I go 4-wheel disks since the coupler will produce an aggravating bumping if no longer pushing fluid to brakes. What did you do with your coupler when you changed to the electric/hydraulic? Thanks for the help.

 

[bruceb58]

Re: Surge drums PLUS elect/hydraulic disks

I removed the master cylinder and bolted the center piece so it wouldn't move.

I see what you are trying to do...make it so ther people can still tow your trailer. I was also thinking about the possibility of others towing my trailer but since I haven't have that happen in 20 years, figured it wasn't going to be a big deal.

I would just put the second set of brakes on the other axle and be done with it. If you are going to go through the trouble of maintaing brakes on two axles, you might as well get full benefit from them. Your surge actuated drum brakes will hardly ever come into play. The really big advantage of using the electric/hydraulic will be negated...that is when you are going down steep hills, surge brake systems have a tendency to drag. You won't have that problem or the backing up problem anymore.

 

[ewk]

Re: Surge drums PLUS elect/hydraulic disks

Thanks for the thoughts Bruce. Sorry for the delayed thank you but I've been away for a few days. Anyway, I haven't decided what I'm going to do. At the least, I'm going electric/hydraulic with discs on at least one axle. I may replace the surge drums with discs after I search around for some more information concerning the original question.

 

[jeeperman]

Re: Surge drums PLUS elect/hydraulic disks

So you want to run two independent brake systems on the trailer. But only one would be active at any time?.
The added safety factor would only work as long as you knew when to activate the surge brakes function.

Why can't you leave the surge brakes as is with a line lock wired into your backup lights?
That way you have two active systems all the time.

If the elec/hyd. is working properly, the surge brakes never engage.
If the elec./hyd. system should fail the surge brakes are still there do do their thing without any switch over by you.