Chevrolet 1977 light duty truck, Service Manual

Page: 398 / 861

Fig. 5-5--Typical Rear Hose Fittings
1. Procure the recom m ended tubing and steel
fitting nuts o f the correct size. (Outside d iam eter o f
tubing is used to specify size.)
2. Cut tubing to length. Correct length m ay be
d e term in ed by m easuring old pipe using a cord and
a d d in g 1 /8 " for each double flare.
3. D o u b le flare tubing ends using a suitable flaring
tool such as J-23530. Follow instructions included in tool
set.
M ake sure fittings are installed before starting
second flare.
W A R N IN G : DOUBLE FLARING TOO L M U S T
BE USED AS SIN G LE FLARING TOOLS
C A N N O T PRODUCE A FLARE STR O N G
E N O U G H TO HOLD T H E NECESSARY
PRESSURE.
4. Bend pipe assembly to match old pipe using a
tubing bender. Clearance o f .75" must be m a in ta in e d to
all moving or v ibrating parts.
BRAKE HOSES
Inspection
The flexible hydraulic brake hose which transmits
hydraulic pressure from the steel brake pipe on the
fram e to the rear axle and to the calipers should be
inspected every 4 months or 6,000 miles (heavy duty
emission vehicles), every 12 m onths or 7,500 miles (light
duty emission vehicles). The brake hose assembly should
be checked for ro ad h azard d am age, for cracks and
chafing o f the outer cover, and for leaks and blisters. A
light and m irro r m ay be needed for an adequate
inspection. If any o f the above conditions are observed
on the brake hose, it will be necessary to replace it.
Front Brake Hose
R e m o va l (fig s . 5 -2 th ru 5 -4 )
1. Raise vehicle on hoist.
2. Clean dirt and foreign m aterial from both hose
end fittings.
3. Disconnect brake pipe from hose fitting using a
back-up wrench on fitting. Be careful not to bend frame
bracket or brake pipe. It m ay be necessary to soak the
connections with p en etratin g oil.
4.
Remove " U " clip from fem ale fitting at bracket
and remove hose from bracket.
5. Remove bolt from caliper end o f hose. Remove
hose from caliper, and discard the two copper gaskets on
either side o f fitting block.
In s ta lla tio n
1. Use new copper gaskets on both sides o f fitting
block, wet bolt threads with brake fluid, then with fitting
orientation flange engaged with the caliper orientation
ledge on JB8 and JF9 (hose located in caliper gate on all
except JB8 and JF9), fasten hose to caliper; torque to
specifications.
2. With weight o f vehicle on suspension, pass
female fitting through fram e or fra m e bracket. Fitting
fits the bracket in only one position. W ith least am ount
of twist in hose, install fitting in this position. There
should be no kinks in hose.
3. Install " U " clip to female fitting at frame
bracket.
4. Attach brake pipe to hose fitting using a backup
w'rench on fitting; torque to specifications.
5. Inspect to see that hose d o e sn ’t make contact
with any p a rt o f suspension. Check in extreme right
h an d and extreme left h an d tu rn conditions. If hose
makes any contact, remove and correct.
6. Bleed brake system.
7. Lower vehicle from hoist.
Rear Brake Hose
R em o val
1. Raise vehicle on hoist.
2. Remove all three brake pipes from hose, two at
junction block and, with the use o f a back-up wrench,
one on the female fitting at bracket. Be careful not to
bend bracket or pipes; use p enetrating oil if necessary.
3. Remove " U " clip and take female fitting out of
bracket (fig. 5-5).
4. Observe position at w'hich junction block is
m ounted to the axle. W h e n installing new hose be sure
this junction block is in the same position.
5. Remove bolt attaching junction block to axle.
In s ta lla tio n
1. T h read both rear axle pipes into ju n ctio n block.
2. Bolt junction block to axle and then torque rear
pipes into block.
3. Pass female end o f hose through bracket;