PEUGEOT 504 Series 1970 Workshop Manual page 465

BRAKES
CHECKING A SERVO·UNIT
I · CHECKING VACUUM
504 petrol engine
-Connect
- vacuum gauge,
tachometer.
- Run engine until fan cuts·in.
- Check 1dltng speed (504 carb. 800 r.p.m., inj. 850).
- Accelerate
to
4,500 r.p.m.
- Ducelernte abruptly.
Maximum vacuum indicated during deceleration
should be equal to or greater than, 500 mm/Hg.
504 Diesel
- Connect vacuum gauge.
- Run engine at fast idling for not less than
1
minute
The indicated vacuum should ne equal to or grea·
ter than, 500 mm/Hg.
IF VACCUM IS LESS THAN 500 mm/Hg.
- Disconnect the valve
(1 ).
- Re check, blocking the valve Gonnection with
the thumb.
1st example Vacuum is still less than 500 mm/Hg.
Air lossi•s
ad1d~nt
ot the valve.
In
p,1rt
c:uhr on 504 petrol.
- abnormal air entry : deteriorat
1011
and/or
lack ot
1191 t"S I
the valve,
hoses and prpes,
carburettor mounting flange,
the
air
d1stnbut1on chamber "rubber" busches
on 504 m1ect1on.
· condition of engine : checl compression
rn
each
cylinder on 504 Diesel.
·abnormal air·entry : deterioration or lack of tight·
ness of the valve and/or hoses and pipes.
·condition of the vacuum pump : first check
bell
tension.
2nd example . Vacuum
is
equal to or greater than,
500mm/Hg.
Reploce the valve fitted with
cl
new seal (2).
- Repeat tt?sts.
If the vacuum is again less than 500 mm/Hg, the servo·
unit is suspect.
NOT A · Tale11 into accounr the fall
m
atmospheric
pressure
above
11n
altitude of 1 OOO m. Thus.
a
vacuum of 370 mm/Hg.
1s
acceprable
at 2000m.
WVIW. ~~lllC:J . OrG