Chevrolet Light Duty Truck 1973 Service Manual page 286

5 -2 0 BRAKES
Safety steel tubing must be double-lap flared at the ends
in order to produce a strong leak-proof joint.
Brake Tube Flaring Tool J-2185-45° is used to form the
double lap flare. It must be equipped with the proper
size die block and upset flare punch for each size tubing
to form the double-lap flare (fig. 35).
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
Figure 36 shows two pieces of tubing, one with single-lap
flare "A" and the other with double-lap flare "B". It will
be noted that the single-lap flare in "A" split the tubing
while the one shown in "B" is well-formed and unbroken
due to the reinforcement of the double wall.
Fig. 35-Flaring Tool J-2185
Fig. 3 6 -Single and Double Lap Flare
Finish
Upset
Flare Punch Flare Punch
J-2185-3 J-2185-26
J-2185-37 J-2185-26
J-2185-4 J-2185-26
The following procedure should be followed in making
up hydraulic brake lines.
Double Lap Flaring
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. Place one-half of the die blocks in the tool body
with the counterbored ends toward the ram guide.
Now lay the tubing in the block with approximately
1/4" protruding beyond the end.
Fit the other half of the block into the tool body,
close the latch plate and tighten the nuts "finger
tight."
4. 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.
5. 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.
37).
. Using the supplied wrench, draw the latch plate nut
6
down tight to prevent the tube from slipping.
Tightening the nuts alternately (beginning with the
nut at the closed hole in the plate), will prevent
distortion of the plate. Remove the punch and the
ram. Now reverse the punch and put it back into
the tool body. Install the ram and tap it until the
upset flare is complete (fig. 38). This completes the
first operation. Remove the ram and the punch.
7. To complete the flare, insert the pointed finish flare
punch and the ram into the tool body. Tap the ram
until a good seat is formed (fig. 39).
NOTE: The seat should be inspected at
intervals during the finishing operation to
avoid over-seating.
. Blow tubing out with compressed air to remove any
8
foreign objects.
UPSET FLARE PUNCH
LATCH PLATE-
DIE BLOCK
TUBE
STOP PLATE
Fig. 3 7 -Positioning Tube
RAM GUIDE
RAM
LIGHT DUTY TRUCK SERVICE MANUAL