Roadmaster 98300 Installation Instructions Manual - Troubleshooting
Troubleshooting
Note: to identify components in the towed vehicle
described below, refer to the complete BrakeMaster
installation instructions. For the most recent copy of
the instructions, visit www.roadmasterinc.com. Select
‘Installation Instructions' under ‘Support.’
Symptom
The motorhome monitor LED does not illuminate,
even though the brakes in the towed vehicle are being
applied.
Solution
1. The monitor LED will not illuminate during very light
braking.
2. Make certain that the monitor patch cord is securely
connected between the two vehicles.
3. The towed vehicle-to-motorhome electrical cord
must also be connected — the monitor system uses it
for the ground wire.
4. The monitor LED is connected to the towed vehicle’s
brake light circuit. If the fuse in the circuit is blown,
the LED will not illuminate. Check the towed vehicle’s
brake lights — if they illuminate when the brake pedal
is depressed, the fuse is good.
5. Is the optional Brake-Lite Relay installed in the
towed vehicle? If so, make certain that the monitor
wire is connected to the towed vehicle’s brake light wire
after the brake light switch, but before the Brake-Lite
Relay — connecting the wire anywhere else will prevent
the monitor LED from functioning.
Symptom
Nothing happens after proper installation.
Solution
1. The motorhome engine must be running — if the
engine is off, there may be insufficient hydraulic pres-
sure to activate BrakeMaster.
2. Check the air line connections. Remove the weather
covers from the quick couplers at both vehicles, and
gently tug on the air line to verify that the quick couplers
are connected.
Check to make certain that the air cylinder quick
coupler is connected to the air line in the passenger
compartment.
3. Check the wiring at the solenoid valve (on the pro-
portioning valve). One of the black wires must be con-
nected to a good chassis ground (Figure 9). The other
black wire must be connected to the motorhome brake
wire downstream from the brake light switch (Refer to
“Wire the proportioning valve.”). Use a test light to con-
firm that the solenoid valve is receiving power when the
motorhome brake pedal is depressed.
If the connections are good, test for proper function
— with the motorhome engine running, have an assistant
depress the motorhome brake pedal while you listen
for a “click” at the solenoid valve. The solenoid valve
should “click” every time the brake pedal is depressed.
4. Disconnect the air line from the “out” compression
fitting on the solenoid valve (Figure 9). Have an as-
sistant depress the motorhome brake pedal — the pro-
portioning valve should release air each time the pedal
is depressed.
A. If there is air at the proportioning valve — follow the
air line back to the air cylinder in the towed vehicle.
Inspect the entire line for deformities caused by exces-
sive heat, and/or kinks in the line, which would restrict
the air flow — replace the entire section of air line if any
are found.
Disconnect the quick couplers to confirm that they
are allowing air to flow through them.
B. If there is no air at the proportioning valve — check
to confirm that the air line between the air compressor
and the proportioning valve is connected to the correct
fitting. It should run from the “in” fitting on the air com-
pressor (Figure 1) to the “in” fitting on the proportioning
valve (Figure 8).
If the air line is connected to the “out” fitting on the
proportioning valve, no air can pass through the valve,
and the BrakeMaster system will not function.
If this is the case, reconnect the line from the air
compressor to the “in” fitting in the proportioning valve.
Symptom
The compressor runs constantly, or runs much more
frequently than I think it should.
Solution
1. Check for leaks in the air system.
2. Make certain that the drain valve on the air compres-
sor air tank is closed. Refer to Figure 15.
3. If a BrakeAway system is installed on the towed
vehicle, make certain that the drain valve on the Break-
Away air reservoir is closed.
4. Make certain that a female quick coupler has been
installed at the rear of the motorhome — a male quick
coupler does not have a check valve to prevent air from
escaping.
Symptom
It seems to require a significant amount of brake
pressure in the motorhome before the BrakeMaster air
cylinder activates in the towed vehicle.
Solution
1. The motorhome engine must be running — if the
engine is off, there may be insufficient hydraulic pres-
sure to activate BrakeMaster.
2. Inspect the air lines for deformities caused by excessive
heat, and/or kinks in the line, which would restrict the air
flow — replace the entire section of air line if any are found.
3. Check for leaks in the air system: after starting the
motorhome, allow the air system to fully charge. De-
press and hold the motorhome brake pedal down.
Cover each joint, fitting and connection in the air
system with a leak check solution.
Tighten any fittings, if necessary, and repeat until
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