Jeep UNIVERSAL CJ-2A - Replace; Trouble Shooting

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BRAKES
ered under the heading, "Wheel Cylinders."
When ever the bra ke lining is renewed in one front
or one rear wheel be sure to perform the same oper -
ation in the opposite front or rear wheel, using the
same brake lining as to color and part number ,
otherwise unequal brak e action will result.
P- 1"2. Hydraul ic Brake Master Cylinder
Should it be necessary to recondition the master
cylinder, the method of removal is obvious.
A fter the master cylinder has been removed it
sh ould be dismantled and thoroughly washed in
alcohol. Never wash any part of the hydraulic
braking system with gasoline or kerosene.
After the parts have all been thoroughly cleaned
with alcohol, make a careful inspect ion, ren ewing
th ose parts w)1ich show signs of being deteriorated.
Inspect the cy lind er bore and if found to be rou gh
it shou ld be honed out or a new cylinder install ed .
Th e cl earance between the piston an d the cylinder
bore should be .001" to .005" [.025 to .127 mm.) .
Clean out the cylinder with alcohol and with a wire
passed through the ports that open from the supply
reservoir into the cylinder bore, make sure that
these passages are free and clear of any foreign
matter. It is our recommendation that a new piston,
primary cup, valve and valve seat be installed
when rebuilding the mas ter cy linder.
I nstall the valve seat in the end of the cylinder
with the flat surface toward the valve.
I nstall the va l ve assembly. Ins tall return spring and
prima ry cup. Th e flat side of the cup goes toward
the piston. Install piston, stop plate, and lock wire
(retainer spring). Inst a ll fitting connection with
new gasket. Fill reservoir h alf full of brake fluid
(see
Par. B -33) and operate the piston with the
piston rod until fluid is ejected at fitting. Install
the master cylinder to the frame and fill to a level
72" [1,3 em.] below the top of the fill hole. M ake
the necessary connections and ad ju st pe d al clear-
ance to 72" [1 ,3 em .) free play
Bleed the brake lines as instructed in Par. P -4.
R echeck the enti re hydraulic brake system to make
sure there are no leaks.
P-13. Wheel Cylinder
Some vehicles are equipped with 1" [25 mm.) di·
ameter front wheel brake cyl i nders, othe rs with
l Ys• )29 mm.) diameter cy l inders. B oth front wheel
cylinders and both r ea r wheel cylinders must have
the same diameter or unequal braking will result .
Make sure a replac e ment brake cylinde r has th e
same part number as the original cylinder.
To remove a wheel cylinder jack up the ve hicle
and remove the wh eel, hub and drum. Disconnect
the brake line at the fitting on the brake backin~
plate. Remove the brake shoe return spring which
allows the brake shoes at the toe, to fall clear of
the brake cylinder. Remove two screws holdin i
wheel cylinder to the backing plate .
R
emove the rubber dust covers on ends of cyl in-
der and th en the piston a nd piston cups and the
spring. See Fig. 281.
230
W ash the parts in clean alcohol. Examine the cylin-
der bore for roughness or scoring. Check fit of pis-
tons to cylinder bore by using a .002" [.051 mm.)
feeler gauge. Wh en reassembling the cylinder, dip
springs, pistons and piston cups in brake fluid. In -
stall sprin g in center of the wheel cylinder. Inst all
piston cups with the c upped surface towards the
spring so th at the flat surface will be against the
piston. I nstall pistons and dust covers. I nstall wheel
cylinder to the backing plate, connect brake line
and install br a ke shoe return sp ring. R eplace wheel,
hub and drum, then bleed the lines as instructed
under heading, "Bleeding Brakes". Adjust brake if
required.
P-14. Keep Grease an d Oil off Brakes
No brake can be expected to work well when grease
or oil is all owed to l eak into the drum from the axle.
Little braking friction can be obta in ed between
brakes and dr ums when the surface is covered with
oil and grease.
Care should be exercised to see that excessive
amounts of lubricants are not put into the front
hubs or the rear axle bearings or differential. Keep
the grease retainers in good condition.
Whenever wheels are removed, it is advisable to
wash off the drums with a suitable solvent so that
all grease a nd dirt are removed. Should there be a
quantity of grease on the linings, th is can also be
washed off with solvent, however, should the linings
be thoroughly saturated wit h grease , the re is noth-
ing that can be done except to replace the lining.
P-1 5. TROUBLE SHOOTING
P-16. Sque aky Br akes
In most cases, squeaks are entire ly eliminated by
correct adjustment of the bra kes. Squeaks may be
ca u sed however, by glazed linings, lining w or e thin
to the point of exposed rivets or by vibration. A
drum will not vibrate wh en the brake is securin g
uniform contact over the entire linin g surface, ex-
cept when due to improp er conditions such as the
linings becoming glazed. Glazed surface of the
brake l inings may be removed by a stiff wire brush.
O ccasionally squeaks are caused by roughened sur -
face of the drum, which can usually be re medied
by rubbing down with emery cloth and by wiping
the brakin gs surface clean. In extreme cases it may
be necessary to reface the drum in a lathe. Should
this be done, do not remove a metal thickness
greater th an .030" [.762 mm.) - .060" [1.52 mm.)
overall diameter.
P-17 . Rattles in Br akes
See that t he te nsion of the springs in the brakes
and attached to the contro l system are sufficient to
return brak es and brake mechanism to their normal
position. R et urn springs are so place d that they
keep all slack out of the control system by tension
on all j oints.
Brakes will not ratt le in s id e t he drum if the sprin gs
hol ding the shoes are kept at the proper tension.