Electric brakes?

[patrick flowers]

>
> Hi Patrick:
>
> Thanks for you input. I hadn't thought about the backing up issue but
> it could be a problem I see. What type of modification to the tow
> vehicle's brake system are you talking about?

Electric brakes require the installation of a "tee" fitting on the tow
vehicle master cylinder to allow the control unit to sense braking
pressure. It's a slight modification, but any modification to the brake
system tends to bother me. Even so, I'd still rather have electric
brakes.

> Do the regular brakes and electric brakes work together off the brake
> pedal operation in normal operation but the electrics can be used
> independently when desired?

The brake control unit(small box approx. 1"H x 3"W X 5"D) mounts under
the dash and is connected to the master cylinder by a steel brake
line(the same as is used for the rest of the brake system plumbing).
It's basically a variable resistor attached to a hydraulic slave
cylinder with a lever protruding out the front of the box. When you
apply the vehicle brakes, hydraulic pressure causes the control to apply
voltage to electromagnets on the trailer brakes. The more pressure you
apply to the brake pedal, the higher the voltage that's applied to the
trailer brakes. To apply trailer brakes without applying the tow
vehicle brakes, you just pull over on the control box lever. The
farther you pull it over, the more voltage you apply to the trailer
brakes.

Hope this makes it a little clearer!
Patrick
- --
Patrick Flowers
Mailtoatri63

The GMC Motorhome Page
http://www.gmcmotorhome.com

 

[scott woodworth]

Ralph,

Several of the trailer brake controller manufacturers sell a unit
that doesn't require tapping into the tow vehicle's brake system. The
controller uses a fore and aft swinging pendulum to sense deceleration
and apply the trailer brakes accordingly.

I think Tecanshaw make a really good unit which received high marks
from a test that Trailer Life Magazine did a few years ago. As I
remember, the only time the unit didn't work with 100% accuracy is going
over hard bumps while traveling down steep hills. It had a tendency to
over apply the trailer brakes momentarally.

- -Scott Woodworth