Recommendations on Trailer Brakes

["Curtis A. Ingraham" <ingraham@xxxxxxxxxxxxxxxx>]

In BMW Digest v09.n1907 John Corbishley <jcorbs@domain.elided> wrote:

> Sorry for the BW, but can any of you give me the pros and cons of 
> "Surge" vs "Electric" trailer brakes.
> 
> I am inclined to favour the surge based on the KISS principle, but 
> most vehicle trailers seem to come with electric.
> 
> Any views on trailer dos and donts would also be appreciated.

I saw lots of good comments earlier.  I'll try to fill in a few
details I'm familiar with.

Most States require brakes on trailers over a certain weight,
usually 1000-1500 pounds.

Virtually all boat trailers with brakes have surge brakes, probably
because electric brakes don't survive the regular dunking that boat 
trailers get.  Almost all rental trailer brakes are surge brakes,
probably because part-time tow vehicles can't be expected to have
electric brake controllers.  Most horse, travel, and other trailers
with brakes have electric brakes; this suggests that electric brakes 
work better than surge brakes, except for the limitations mentioned 
above.

Surge brakes are simple and require no special adjustments.  Surge
brakes are sometimes slow to respond, but some new models solve that.

Electric brake controllers typically have adjustments for trailer
weight, onset delay, and maybe some other things, so they can be 
tweaked for the particular load and towing conditions.  Electric 
brakes can be very touchy if set up wrong.

Michel Potheau's comments about backing with surge brakes are correct, 
but may be less puzzling with some further explanation.  Surge brakes
activate when the trailer pushes on the truck or vice versa.  If you
shift to reverse, then hammer the gas, the surge brakes will lock
up.  This is quite amusing, unless you want to back up.  A similar 
effect occurs when backing uphill; depending on the slope, this can 
be anything between challenging and impossible.  Something different 
happens when backing slowly downhill -- the surge brakes never 
activate.  Gentle backing on level ground is not a problem.  

The backing uphill problem can be solved with a surge brake lockout
device.  Some models don't have this.  Some have a lever for this
on the trailer tongue; this is the mechanism that Michel Drainville 
described.  And some models have an electrically-operated brake
lockout.  You hook this up to the backup light circuit of the truck, 
and it disables the trailer brakes when in reverse.  This is more
convenient than getting out and flipping a lever. ;)  

Dual axle trailers should have brakes on both axles.  If only one
axle has brakes, it should be the rear axle.

The best source of towing and tow vehicle info is Trailer Boats
Magazine, <www.trailerboats.com>.  TBM publishes tow vehicle tests,
trailer maintenance info, and towing info monthly. 

Don't forget to change the brake fluid in your trailer just as you 
do for your Bimmer.

Curt Ingraham
Tested and licensed for doubles & triples
72 2002tii
Oakland, CA

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