Jeep 1996 Grand Cherokee Service Manual - page 968
(3) Remove push rods. Retain the push rods,
bridges, pivots and rocker arms in the same order
and position as removed.
(4) Inspect the springs and retainer for cracks and
possible signs of weakening.
(5) Remove the spark plug(s) adjacent to the cylin-
der(s) below the valve springs to be removed.
(6) Connect an air hose to the adapter and apply
air pressure slowly. Maintain at least 621 kPa (90
psi) of air pressure in the cylinder to hold the valves
against their seats. For vehicles equipped with an air
conditioner, use a flexible air adaptor when servicing
the No.1 cylinder.
(7) Tap the retainer or tip with a rawhide hammer
to loosen the lock from the retainer. Use Valve Spring
Compressor Tool MD-998772A to compress the spring
and remove the locks (Fig. 31).
(8) Remove valve spring and retainer (Fig. 31).
(9) Remove valve stem oil seals (Fig. 31). Note the
valve seals are different for intake and exhaust
valves. The top of each seal is marked either INT
(Intake) or EXH (Exhaust). DO NOT mix the seals.
INSTALLATION
CAUTION:
Install oil seals carefully to prevent
damage from the sharp edges of the valve spring
lock grove.
(1) Lightly push the valve seal over the valve stem
and valve guide boss. Be sure the seal is completely
seated on the valve guide boss.
(2) Install valve spring and retainer.
(3) Compress the valve spring with Valve Spring
Compressor Tool MD-998772A and insert the valve
locks. Release the spring tension and remove the
tool. Tap the spring from side-to-side to ensure that
the spring is seated properly on the engine cylinder
head.
(4) Disconnect the air hose. Remove the adaptor
from the spark plug hole and install the spark plug.
(5) Repeat the procedures for each remaining valve
spring to be removed.
(6) Install the push rods. Ensure the bottom end of
each rod is centered in the plunger cap seat of the
hydraulic valve tappet.
(7) Install the rocker arms, pivots and bridge at
their original location.
(8) Tighten the bridge capscrews alternately, one
at a time, to avoid damaging the bridge. Tighten the
capscrews to 28 N·m (21 ft. lbs.) torque.
(9) Install the engine cylinder head cover.
ENGINE CYLINDER HEAD
This procedure can be done with the engine in or
out of the vehicle.
REMOVAL
(1) Disconnect negative cable from battery.
WARNING:
DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR
DRAIN COCK WITH THE SYSTEM HOT AND PRES-
SURIZED BECAUSE SERIOUS BURNS FROM THE
COOLANT CAN OCCUR.
(2) Drain the coolant and disconnect the hoses at
the engine thermostat housing. DO NOT waste reus-
able coolant. If the solution is clean and is being
drained only to service the engine or cooling system,
drain the coolant into a clean container for reuse.
(3) Remove the air cleaner assembly.
(4) Remove the engine cylinder head cover.
(5) Remove the capscrews, bridge and pivot assem-
blies and rocker arms.
(6) Remove the push rods. Retain the push rods,
bridges, pivots and rocker arms in the same
order as removed.
(7) Loosen the serpentine drive belt at the power
steering pump, if equipped or at the idler pulley
(refer to Group 7, Cooling System for the proper pro-
cedure).
(8) If equipped with air conditioning, perform the
following:
(a) Remove the bolts from the A/C compressor
mounting bracket and set the compressor aside.
(b) Remove
the
air
conditioner
compressor
bracket bolts from the engine cylinder head.
(c) Loosen the through bolt at the bottom of the
bracket.
Fig. 31 Valve and Valve Components
ZJ
4.0L ENGINE
9 - 31
REMOVAL AND INSTALLATION (Continued)