Chevrolet DB90 Series, Руководство по обслуживанию

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S ec. 5B -47
SECTION 5B
A in & n < J z & L
BRAKE ADJUSTMENTS
Information re la tiv e to brake pedal and brake
trea d le adjustm ents a re the sam e a s given in
S erv ice Manual S T 135-70, except for Conventional
Cab M odels. The suspended pedal installation
shown in figu re 2, page 5-10, is no lon ger used.
A ll Conventional Cab M odels u se a treadle type
in stallation a s shown in figu re 5, page 5-31. This
i s the sam e type a s u sed on the 90 S e r ie s and is
NOT adjustable.
BRAKE APPLICATION VALVES
A ll inform ation in S erv ice Manual ST 135-70
under above subject applies to v e h ic le s covered
by th is supplem ent except that pertaining to "Con­
ventional Cab Models" on page 5-38. Information
under the heading of "Aluminum T ilt Models"
(pages 5-38 - 5-39) applies to Conventional Cab
M odels covered by this supplem ent.
MOISTURE EJECTOR VALVE
M odels HH, HC, JH, JC 90 u se a different type
m oistu re ejecto r valve than the type d escrib ed on
pages 5-37 and 5-38 of S erv ice Manual ST135-70.
An adapter fitting is part of the valve and is thread­
ed into a te e in the drain port of the air tank.
Inlet and exhaust v a lv es in the m oistu re e je c ­
tor a r e norm ally c lo se d . When a ir c o m p resso r is
operating to in c r e a se r e se r v o ir p r e ssu r e the inlet
valve opens allow ing a ir and contam inants to c o l­
le c t in the sump of the ejecto r. When cut-out p r e s ­
su re i s reached, the spring action of the valve
guide c lo s e s in let valve.
When r e se r v o ir p r e ssu r e drops sligh tly (ap­
prox. 2 psi) a ir p r e ssu r e in the sump cavity opens
exhaust valve and allow s w ater and contam inants
to be ejected . When p r e ssu r e in sump drops, ex­
haust valve c lo s e s .
The length of tim e the exhaust valve rem ains
open and the amount of w ater and contam inants
ejected depends upon the sump p r e ssu r e and the
r e se r v o ir p r e ssu r e drop that o ccu rs each tim e
a ir i s used from the sy ste m .
If n e c e ssa r y , manual draining through the
valve can be accom plished by moving the w ire in
the exhaust port upward and holding it until draining
i s com pleted.
To rem ove valve from v eh icle, drain a ir from
sy ste m and unthread adapter from tee in air tank
drain port.
To in sta ll valve and adapter a ssem b ly , sim ply
thread adapter into tee in air tank drain port.
AIR LINES
NYLON TUBING
Some v e h ic le s covered by th is supplem ent u se
nylon tubing for air lin e s in a r e a s w here such
m a teria l i s su itab le. Nylon tubing i s fle x ib le, dur­
a b le, and w eather resista n t.
In the event it is n e c e ssa r y to rep la ce a nylon
lin e it w ill be n e c e ssa r y to a ssem b le the ends to
the tubing which m ust be cut to required length.
R efer to figu re 1.
1. Cut nylon tube to required length.
2. Install nut and ring over tube.
3. In sert m andrel into barb body.
4. P la c e m andrel and barb body into jig.
5. Thread nut onto m andrel threads fin g er-
tight up to jig fa c e.
6. Push nylon tube in jig over barb body until
nylon tube se a ts against barb body.
7. P ush ring into jig until it s e a ts against
barb body.
8. Hold jig se cu rely w ith a w rench or in a
v is e .
9. Withdraw mandrel from barb body and
nylon tube by turning nut on mandrel threads.
10. Check sight notch in ring to be su r e nylon
tubing i s sea ted against barb body flange.
11. In stall fitting at other end of nylon tube
u sing above p rocedure.
B A R B B O D Y M A N D R EL
L
R IN G
/
N U T
/
TU BE
/
ASSEM BLY TOO L AND COMPONENTS
PLACIN G TUBING IN JIG
W ITH D RAW IN G MANDREL FROM BARB BO DY
Figure 1—Nylon
Tubing
Assem bly
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT