Roadmaster 98300 Installation Instructions Manual - page 8
6
Install the proportioning valve
E. The closer the proportioning valve is to the air
compressor, the less air line will have to be routed
between them later.
The proportioning valve must be mounted with
the bleeder valve pointing up. The valve will not-
bleed the brake system if it is not pointing up,
which will cause brake failure.
3. Before attaching the proportioning valve, first re-
move any residual vacuum from the motorhome’s brake
power booster (if the motorhome is so equipped) — ap-
ply the motorhome brake several times, with the engine
off.
4. Next, remove the master cylinder reservoir cover
and (if necessary) fill the reservoir with brake fluid, up
to the maximum marking. Reattach the cover.
Wear appropriate eye protection when work-
ing on the brake system. If brake fluid comes into
contact with your eyes, follow the manufacturer’s
instructions.
Failure to follow these instructions may cause
severe eye injury.
Note: If the motorhome brake line has metric fit-
tings it will be necessary to use a metric-to-standard
T-fitting to attach the proportioning valve. This fitting
is not supplied in the kit.
Identify the size of the metric brake line before the
installation. If it is 10 or 12 millimeters, contact ROAD-
MASTER — T-fittings in both sizes are available.
The 10 millimeter T-fitting (part number 7923) fits
virtually all metric brake lines for this application; the
part number for the 12 millimeter fitting is 7921.
In the unlikely event that the brake line is not 10
or 12 millimeters, we recommend you contact a local
hose and fitting shop or other contractor and arrange to
have the brake line cut and flared so that the standard
brake line tees supplied in the kit can be installed.
5. Position a bucket or pan under the brake union (or
other point you have chosen to tee into the brake line)
to catch any brake fluid.
Clean any dirt or debris away from the brake union
and use two open end or line wrenches to disconnect
both ends of the brake line from the union. (It may be
necessary to soak the connections with penetrating oil
to break them free.)
Do not bend the brake line, or damage the threads.
When the brake line is disconnected from the union,
plug the line going toward the master cylinder to pre-
vent any further loss of brake fluid. A rubber plug (part
number 450011) is included in the kit for this purpose.
continued on next page
Figure 14
continued from preceding page
Loop the section of steel brake line, as shown
in Figure 13, so that it can expand and contract to
absorb road vibrations. Otherwise, this section of
brake line may detach or break, which will cause
a loss of brake pressure.
CAUTION
If you are installing BrakeMaster in a Ford Class
C motorhome, tee into the front hydraulic brake
line. The rear hydraulic brake line does not supply
sufficient hydraulic pressure to brake the towed
vehicle properly.
2. Determine the best location to attach the proportion-
ing valve bracket, based on the following:
A. There must be adequate room on the frame
to mount the proportioning valve assembly (Figure 14)
securely in place.
B. When the proportioning valve is installed, the
bleeder valve (Figure 14) must point up.
C. The proportioning valve and its attachments
must not interfere with the movement or proper opera-
tion of any chassis components.
Also, there must be sufficient clearance to bolt the
proportioning valve bracket to the frame without caus-
ing damage to any other component.
D. The proportioning valve assembly must be in-
stalled close enough to the motorhome’s brake line to
allow the included section of brake line to reach the
brake union (or other point you have chosen to tee into
the brake line).