Brake Drum Machining; Brake Tube Flaring - Jeep cherokee 2000 Service Manual

5 - 14 BRAKES
SERVICE PROCEDURES (Continued)
mounted on-vehicle lathe is recommended. This type
of lathe trues the rotor to the vehicles hub/bearing.
CAUTION: Brake rotors that do not meet minimum
thickness specifications before or after machining
must be replaced.

BRAKE DRUM MACHINING

The brake drums can be machined on a drum lathe
when necessary. Initial machining cuts should be lim-
ited to 0.12 - 0.20 mm (0.005 - 0.008 in.) at a time as
heavier feed rates can produce taper and surface
variation. Final finish cuts of 0.025 to 0.038 mm
(0.001 to 0.0015 in.) are recommended and will gen-
erally provide the best surface finish.
Be sure the drum is securely mounted in the lathe
before machining operations. A damper strap should
always be used around the drum to reduce vibration
and avoid chatter marks.
The maximum allowable diameter of the drum
braking surface is stamped or cast into the drum
outer edge.
CAUTION: Replace the drum if machining will
cause the drum to exceed the maximum allowable
diameter.

BRAKE TUBE FLARING

A preformed metal brake tube is recommended and
preferred for all repairs. However, double-wall steel
tube can be used for emergency repair when factory
replacement parts are not readily available.
Special bending tools are needed to avoid kinking
or twisting of metal brake tubes. Special flaring tools
are needed to make a double inverted flare or ISO
flare (Fig. 14).
DOUBLE INVERTED FLARING
(1) Cut off damaged tube with Tubing Cutter.
(2) Ream cut edges of tubing to ensure proper
flare.
(3) Install replacement tube nut on the tube.
(4) Insert tube in flaring tool.
(5) Place gauge form over the end of the tube.
(6) Push tubing through flaring tool jaws until
tube contacts recessed notch in gauge that matches
tube diameter.
(7) Tighten the tool bar on the tube
(8) Insert plug on gauge in the tube. Then swing
compression disc over gauge and center tapered flar-
ing screw in recess of compression disc (Fig. 15).
(9) Tighten tool handle until plug gauge is
squarely seated on jaws of flaring tool. This will start
the inverted flare.
Fig. 14 Inverted Flare And ISO Flare
1 – ISO-STYLE FLARE
2 – DOUBLE INVERTED-STYLE FLARE
(10) Remove the plug gauge and complete the
inverted flare.
Fig. 15 Inverted Flare Tools
ISO FLARING
To make a ISO flare use Snap-On
TFM-428 or equivalent.
(1) Cut off damaged tube with Tubing Cutter.
(2) Remove any burrs from the inside of the tube.
(3) Install tube nut on the tube.
XJ
Flaring Tool