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1 .
8.
N O T E : l f t h e c l e a r a n c e b e t w e e n t h e g a u g e b o d y
and adjusting nut is 0.4 mm (0.02 in), the pushrod-
to-piston clearance is 0 mm. However, if the clear-
ance between the gauge body and adjusting nut is
0 mm, the pushrod-to-piston clearance is 0.4 mm
(0.02 in) or more. Therefore it must be adjusted and
rechecked.
lf clearance is incorrect, loosen the star locknut and
turn the adjuster in or out to adjust.
NOTE:
. Adjust the clearance while the specified vacuum
is applied to the booster.
.
Hold the clevis while adjusting.
Tighten the star Iocknut securely.
Remove the special tool.
0 - o.il mm l0 - 0.02 inl
Brake Booster Inspection
Functions Tgst
1. With the engine stopped, depress the brake pedal
several times to deplete the vacuum reservoir, then
depress the pedal hard and hold it for 15 seconds. ll
t h e p e d a l s i n k s , e i t h e r t h e m a s t e r c y l i n d e r i s
bypassing internally; or the brake system (master
cylinder, lines, modulator proportioning valve, or
caliper) are leaking.
Start the engine with the pedal depressed. lf the
pedal sinks slightly, the vacuum booster is operat-
ing normally. lf the pedal height does not vary, the
booster or check valve is faulty.
With the engine running, depress the brake pedal
l i g h t l y . A p p l y j u s t e n o u g h p r e s s u r e t o h o l d b a c k
a u t o m a t i c t r a n s m i s s i o n c r e e p , l f t h e b r a k e p e d a l
s i n k s m o r e t h a n 2 5 m m ( 1 . 0 i n . ) i n t h r e e m i n u t e s ,
t h e m a s t e r c y l i n d e r i s f a u l t y . A s l i g h t c h a n g e i n
pedal height when the A,,/C compressor cycles on
a n d o f f i s n o r m a l . ( T h e A / C c o m p r e s s o r l o a d
changes the vacuum available to the booster.)
Leak Test
1. Depress the brake pedal with the engine running,
then stop the engine. lf the pedal height does not
vary while depressed for 30 seconds, the vacuum
b o o s t e r i s O K . l f t h e p e d a l r i s e s , t h e b o o s t e r i s
fau lty.
2. With the engine stopped, depress the brake pedal
s e v e r a l t i m e s u s i n g n o r m a l p r e s s u r e . W h e n t h e
pedal is first depressed, it should be low. On con-
secutive applications, the pedal height should grad-
ually rise. lf the pedal position does not vary, check
the booster check valve.
Boostor Ch€ck Valve T6st
1. Disconnect the brake booster vacuum hose at the
booster,
Start the engine and let it idle. There should be vac-
uum available. It no vacuum is available. the check
v a l v e i s n o t w o r k i n g p r o p e r l y . R e p l a c e t h e b r a k e
booster vacuum hose and check valve, and retest.
VACUUM HOSE
(Check valve built-in)
STAR LOCKNUT
22 t{.m
12.2 ksl.m, 16lbf.ftl
cLEVtS
ADJUSTER
ADJUSTMENT GAUGE
07JAG - SD40t00
9. Adjust the pushrod length as shown if the booster
is removed.
1 1 6 1 0 . 5 m m
14.61 0.02 inl
PUSHROD
LOCKNUT
15 N m 11.5 kgf m, 11 lbf'ftl
10. Instali the master cylinder.
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Table of Contents
Troubleshooting
