Chevrolet 30 Series 1967 Service Manual page 255

Fig. 67—H ydraulic Brake Tube Flaring Tool
layer flexible steel, copper coated and tin plated tubing
which resists corrosion and also stands up under the high
pressures which are developed when applying the brakes.
On 1/2-ton models brake tubing of 3/16" diameter is used
for all hydraulic brake pipes except the line between
main cylinder and tee fitting on frame right hand side rail
which is 1 /4 ". Excepting the 5/16" rear wheel trunk line
and main cylinder to brake booster line on tandem
models, all hydraulic lines on all except the
are 1/4" brake tubing. In making up hydraulic brake
pipes, it is important that the ends of the tubing be flared
properly for the compression couplings.
tubing is properly flared, the couplings will leak and the
brakes will become ineffective.
This safety steel tubing must be double-lap flared at
the ends in order to produce a strong leak-proof joint.
The Tool J-6892 (fig. 67) must be equipped with the
proper size die block and upset flare punch for each size
tubing to form the double-lap flare.
The proper size die blocks and upset flare punches
are as follows:
Tubing Size Die Block
3/16" J-2185-27
1/4" J-2185-28
5/16" J-2185-29
NOTE: These tools are also part of J-6892.
Figure shows two pieces of tubing—one with a
6 8
Fig . 68—Single and Double Lap Flare
ton truck
1 / 2
Unless the
Upset Finish
Flare Punch Flare Punch
J-2185-3 J-2185-26
J-2185-37 J-2185-26
J-2185-4 J-2185-26
Fig. 69—Flaring O p era tio n —Positioning Tubing
single-lap flare and the other with a double-lap
" A "
flare " B " . It will be noted that the single-lap flare splits
the tubing while the double-lap flare shown in
heavy, well-formed joint.
The following procedure should be followed in making
up hydraulic brake pipes:
1. Cut the tubing to the desired length, using Tool
J-8000. Square off ends of tube and ream sharp
edges with reamer tool provided on the tube cutter.
2. Install compression couplings on tubing and dip end
of tubing to be flared in hydraulic brake fluid. This
lubrication results in better formation of the flare.
3. Select the correct size upset flare punch. One end
of this punch is hollowed out to gauge the amount of
tubing necessary to form a double-lap flare.
4. Slip the punch into the tool body with the gauge end
toward the die blocks, install the ram and tap lightly
until the punch meets the die blocks and they are
forced securely against the stop plate (fig. 69).
5. Draw latch plate nuts down tight to prevent tube from
slipping. Draw nuts down alternately beginning with
nut on closed side to prevent distortion of plate.
. Remove punch and ram. Reverse punch and place
6
back in tool body. Install ram and tap lightly until
face of punch contacts face of die blocks to complete
first flare operation (fig. 70).
7. Remove ram and punch.
. Insert finish flare and ram in tool body and tap ram
8
until a good seat is formed (fig. 71).
9. Blow tubing out with compressed air.
BRAKE PIPE DISTRIBUTION AND SWITCH
ASSEMBLY (Fig. 8)
Removal
1. Disconnect battery cable.
2. Disconnect electrical lead from pressure differential
switch.
Fig. 70—Flaring O peration—First Flare
BRAKES 5-41
UPSET FLARE PUNCH r RAM GUIDE
RAM
is a
" B "
CHEVROLET TRUCK SERVICE M ANUAL