Disc Servicing; Installing Boot To Caliper; Installing Boot To Piston; Minimum Requirements - Chevrolet CHEVY VAN G10 SERIES Service Manual

BRAKES 5-20
w ith clean brake fluid. Position the seal in the caliper
bore groove.
2. Lubricate the piston w ith clean brake fluid and assemble
a new boot in to the groove in the piston so th a t the fold
faces the open end o f the piston as shown in Figure 38.
3. Insert the piston in to the caliper bore using care n o t to
unseat the seal an d force (5 0 to 100 pounds force
required) the piston to the b o tto m o f the bore.
4. Position th e dust b o o t in the caliper counterbore and seat
using B oot Installer T ool J-22904 as show n in Figure 39.
C A U T IO N : Check the boot installation to make
sure th at the retaining ring moulded into the boot is
not bent and th at the boot is installed below the
caliper face and evenly all around.
5. Install the brake hose and screw in the caliper inlet using
new copper gaskets.
C A U T IO N : See "C a u tio n "
section.
Hose must be positioned in the caliper locating
gate (between locating
positioning to caliper.
Installation
N O T E : Installation of the caliper and mounting
parts (rubber bushings, sleeves, bolts, and shoe and
lining assemblies) is the same as for: "Shoe and
Lining Disc Brake" except fo r the steps given below.
1. C onnect the brake hose to th e brake line at the frame
bracket.
C A U T IO N : See "C a u tio n "
section.
2. Bleed the calipers using the m ethod outlined in the
beginning o f this section.
Fig. 3 8 —Installing Boot to Piston
on Page 1 of this
beads) to assure proper
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B O O T INSTALLER
J - 2 2 9 0 4
Fig. 3 9 —In s ta llin g B o o t to C alipe r

DISC SERVICING

Servicing o f the brake disc is extrem ely critical since
accurate control o f the disc tolerances is necessary to ensure
proper brake operation.
N O T E : A ll brake disc have a m inim um thickness
dimension cast into them . This dimension is the
m inim um wear dimension and not a refinish dim en­
sion. Do not refinish a brake disc th a t will not meet
the specifications as shown below after refinishing.
M IN IM U M T H IC K N E S S
A F T E R R E F IN IS H IN G
1.2 3 0
.98 0

Minimum Requirements

T h e d is c brake surfaces
specifications.
1. M ust be flat radially w ithin .002 T .I.R .
2. Must be parallel w ith each o th er w ithin .003 T .I.R . when
checked radially.
3. T otal circum ferential thickness variation at any radius
m ust n o t exceed .0005 in 360°.
4. When m o u n ted on bearing cups, lateral run-out m ust not
exceed .005 T .I.R . and m axim um rate o f change m ust
n o t exceed .001 in 30°.
5. Both surfaces m ust be free o f scratch marks and porosity.
6
. Finish is to be 20-60 m icro inches and m ust n o t be
circum ferential (directional).
7. B oth surfaces m ust be square w ith bearing cup centerline
w ithin .003 T .I.R .
DUST
BOOT
R E P L A C E M E N T
(DISCARD)
T H IC K N E S S
1.215
.965
m ust m eet the following
C H E V Y V A N SH O P M A N U A L