must refer to the “Troubleshooting” section in the
owner’s manual and repair the fault before towing.
Evaluate the braking pressure
InvisiBrake’s braking pressure has been pre-set at
the factory at a level appropriate for most towed ve-
hicles. While there may be no adjustment necessary,
you
must
evaluate the braking pressure.
However, do not simply set the pressure according to
the chart. In addition to the vehicle's make, model and
year, the correct pressure is also dependent upon…
•
…whether the brake pedal clamp is positioned as
low as possible on the brake pedal arm; and
•
…the number of curves in the cable between the
cable anchor bracket and the air cylinder.
The higher the clamp is positioned on the brake
pedal arm, and the more curves in the cable, the higher
the braking pressure must be set.
Test-drive the motorhome and towed vehicle
1.
Drive the motorhome and towed vehicle for a short
distance, making six to eight stops.
The degree to which the brake pressure setting will
affect the motorhome will vary, depending on the size
and weight of the motorhome in comparison to the size
and weight of the towed vehicle —
continued on next page
Test drive the motorhome
Drive the motorhome for a short distance, making a
few stops. Get a good feel for the motorhome's brak-
ing ability. Later, you will compare how the motorhome
brakes by itself with how it brakes with the towed ve-
hicle and InvisiBrake.
Connect the vehicles for towing
1.
According to the manufacturer, make all adjustments
necessary to prepare the vehicle for towing. Refer to
the owner’s manual or call the dealership for vehicle-
specific information.
2.
Make all connections between the towed vehicle and
the motorhome, including tow bar, wiring kits, monitor
wire patch cord, etc.
Test the system with the motorhome running
The following tests can be performed with the motor-
home and towed vehicle stationary. However, the mo-
torhome engine should be running, as many motor-
homes do not supply enough voltage to activate In-
visiBrake unless the engine is running.
1. Confirm braking
— with the motorhome engine run-
ning, depress and hold the motorhome brake pedal
down. The towed vehicle’s brake pedal will be de-
pressed. Then, release the motorhome brake pedal.
At the towed vehicle, the brake pedal will retract.
Confirm that the ¼" vacuum hose (Figure 12) is at-
tached to the controller. If it is not, use a hose clamp
or other crimping device to hold it in place.
If the vacuum hose has come loose, use a hose
clamp or other crimping device to hold it in place.
Otherwise, InvisiBrake will not function. Insuf-
ficient braking pressure will lengthen stopping
distance, resulting in property damage, personal
injury or even death.
2. Confirm that the motorhome monitor is function-
ing
— the LED will illuminate after the motorhome’s
brake pedal is depressed and stop illuminating when
the brake pedal is released.
3. Confirm the proper operation of the extended
braking protection mode
— depress and hold the
motorhome’s brake pedal down. The towed vehicle’s
brake pedal will be depressed. After approximately 15
seconds, the brake pedal will retract, even though the
motorhome brake pedal is still depressed.
4. Confirm the proper operation of the audio alert
— in the
towed vehicle
, depress and hold the brake
pedal down. After approximately 20 seconds, the audio
alert will sound in the motorhome. (To cancel the audio
alert, release the towed vehicle’s brake pedal.)
If InvisiBrake fails any of the above tests, you
Test the system; evaluate the brake pressure setting
16
For vehicles with full-time
(‘active') power braking systems…
I
MPORTANT
— if the towed vehicle is a hybrid
or a Hummer H3 it may have full-time (‘active’)
power brakes. A vehicle with ‘active’ brakes will
have power brakes even with the ignition off.
If the towed vehicle does have full-time (‘active’)
power brakes, the brake pressure setting
must
be
lower than the factory setting before proceeding
with the test — First, follow the instructions under
“If necessary, change the brake pressure setting”
(on the next page) to lower the setting. Then go
to “Test-drive the motorhome and towed vehicle”
(below).
CAUTION
If the towed vehicle has full-time (‘active’)
power brakes, the brake pressure setting must
be lowered before the test drive. Otherwise,
InvisiBrake will apply excessive force to the
towed vehicle’s brakes, which will ‘flat-spot’
the tires, damage the braking system or cause
other non-warranty damage.
