[JackStraw]

my wife's 99 g.c. 4.0 is leaking coolant from the water pump again, trusted local repair guy did the first replacement about 2.5 years ago, that one lasted 1.5 years and then they had to replace that one 1 year ago(aftermarket pump was still under warranty, but had to pay labor again). when the original went bad it was the bearing, because it was making an awful noise, but never leaked coolant, the last 2 times it has leaked coolant, but the pump has not made any noise. does that sound like they just didnt get a good seal on it? anyway, i want to go with an oem pump this time, and do the job myself. any tricks or special tools needed to do this job? i searched water pump, and didnt really find a good step by step for doing this job. i would appreciate it if someone would give me a play by play and give me the heads up on the major difficulties/tricks to doing this job right, thanks.

[Katesdad]

your in luck Im doing it tomorrow.
http://www.stu-offroad.com/engine/ra...radiator-4.htm

might help even if its for a TJ.

I believe your clutch fan may be bad. ???

[indept]

Here's from my 2000 Factory Service Manual, as far as the viscous fan instruction, you probably don't have one, just the electric fan like my WJ has so you can ignore that part


REMOVAL AND INSTALLATION
WATER PUMP—4.0L ENGINE
CAUTION: If the water pump is replaced because of
mechanical damage, the fan blades and viscous fan
drive should also be inspected. These components
could have been damaged due to excessive vibration.
REMOVAL
The water pump can be removed without discharging
the air conditioning system (if equipped).
The water pump impeller is pressed on the rear of
the pump shaft and bearing assembly. The water
pump is serviced only as a complete assembly.
NOTE: The water pump can be replaced without
discharging the A/C system.
WARNING: DO NOT REMOVE THE BLOCK DRAIN
PLUG(S) OR LOOSEN RADIATOR DRAINCOCK
WITH THE SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM COOLANT CAN OCCUR.
DO NOT WASTE reusable coolant. If the solution
is clean, drain coolant into a clean container for
reuse.
(1) Disconnect negative battery cable at battery.
(2) Drain the cooling system.
(3) The thermal viscous fan drive is attached
(threaded) to the water pump hub shaft. Remove fan/
viscous fan drive assembly from water pump by turning
mounting nut counterclockwise as viewed from
front. Threads on viscous fan drive are RIGHT
HAND Do not attempt to remove fan/viscous fan
drive assembly from vehicle at this time.
(4) If water pump is being replaced, do not unbolt
fan blade assembly from thermal viscous fan drive.
(5) Remove fan shroud-to-radiator nuts (Fig. 28).
Do not attempt to remove fan shroud at this time.
(6) Remove fan shroud and fan blade/viscous fan
drive assembly from vehicle as a complete unit.
(7) After removing fan blade/viscous fan drive
assembly, do not place thermal viscous fan drive in
horizontal position. If stored horizontally, silicone
fluid in viscous fan drive could drain into its bearing
assembly and contaminate lubricant.
Loosen but do not remove the water pump pulley
mounting bolts.
The drive belt is equipped with a spring loaded
automatic belt tensioner. Relax tension from belt by
rotating tensioner clockwise (as viewed from front)
When all belt tension has been relaxed, remove
accessory drive belt.
Remove the water pump pulley.
(8) Remove the idler pulley (located over the water
pump).
WARNING: CONSTANT TENSION HOSE CLAMPS
ARE USED ON MOST COOLING SYSTEM HOSES.
WHEN REMOVING OR INSTALLING, USE ONLY
TOOLS DESIGNED FOR SERVICING THIS TYPE OF
CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER
6094) (Fig. 29) SNAP-ON CLAMP TOOL (NUMBER
HPC-20) MAY BE USED FOR LARGER CLAMPS.
ALWAYS WEAR SAFETY GLASSES WHEN SERVICING
CONSTANT TENSION CLAMPS.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps (Fig. 30). If
replacement is necessary, use only an original
equipment clamp with matching number or letter.
(9) Remove lower radiator hose from water pump.
Remove heater hose from water pump fitting.
(10) Remove the five pump mounting bolts (Fig.
31) and remove pump from vehicle. Discard old gasket.
Note that one of the five bolts is longer than the
other bolts.
(11) If pump is to be replaced, the heater hose fitting
must be removed. Note position of fitting before
removal.
INSTALLATION
(1) If pump is being replaced, install the heater
hose fitting to the pump. Use a sealant on the fitting
such as Mopary Thread Sealant With Teflon. Refer
to the directions on the package.
(2) Clean the gasket mating surfaces. If the original
pump is used, remove any deposits or other foreign
material. Inspect the cylinder block and water pump
mating surfaces for erosion or damage from cavitation.
(3) Install the gasket and water pump. The silicone
bead on the gasket should be facing the water
pump. Also, the gasket is installed dry. Tighten
mounting bolts to 30 N·m (22 ft. lbs.) torque. Rotate
the shaft by hand to be sure it turns freely.
(4) Connect the radiator and heater hoses to the
water pump.
(5) Position water pump pulley to water pump
hub. Tighten bolts 28 N·m (250 in. lbs.).
Install the idler pulley. Tighten the bolt 47 N·m (35CAUTION: When installing the serpentine engine
accessory drive belt, the belt MUST be routed correctly.
If not, the engine may overheat due to the
water pump rotating in the wrong direction. Refer to
the Belt Removal and Installtion in this group for
appropriate belt routing. You may also refer to the
Belt Routing Label in the vehicle engine compartment.
Install accessory drive belt.
(6) Install fan blade and viscous fan drive onto
water pump.
(7) Fill cooling system with coolant and check for
leaks. Refer to Refilling Cooling System in this
group.
(8) Connect battery cable to battery.
(9) Start and warm the engine. Check for leaks.

[JackStraw]

any special way to tell if fan clutch is bad?

[indept]

Check for latteral play (grab the fan and check for play by pulling forward & backward, there should be no play), otherwise it should spin when first started cold, then free wheel (almost stop) until the temp gets hot, then start spinning at full engine speed.

[JackStraw]

well, if the fan clutch is bad, is that making the water pumps go out prematurely, and if so, how?

[PlatinumZJ]

You might consider investing in a Haynes Manual

[PlatinumZJ]

Originally Posted by JackStraw

well, if the fan clutch is bad, is that making the water pumps go out prematurely, and if so, how?

if you have a mechanical fan then the fan is attached to the water pump shaft. the fan clutch engages and disengages the fan. if the fan or clutch is out of balance (e.g., wobbles) it will prematurely fail the water pump bearing.

If you have a electric fan - - - never mind.

[JackStraw]

yeah platinumzj i have the haynes manual, but find it lacking in some areas i just ordered one of those service manual cds off of ebay, so we will see if it is any better, if not, i'm out 12 bucks.
ok i did some more testing today, i drove the jeep around for about 15 minutes in 90 degree weather and got the temp gauge up to 210(which is as high as it ever goes), then got out and left the jeep running, and looked at the mechanical fan, it was not spinning that fast, definately not as fast as the other pulleys(i know on my 1992 chevy blazer 350, the fan spins a whole lot faster), this was at idle speed. i then kept the gas pedal pushed down and had the engine rpms at ~2500 and the fan was still going the same speed. the stock electrical fan(my jeep has both) was not running at all, and did not turn on after i cut the jeep off, so does mean i also have a bad e-fan?
also, when i put water in the overfill tank today, it started leaking out of the water pump area, without the jeep running, and it also leaks while the jeep is running, and really runs out right after the engine is cut off and running a while. so it looks like i might have a bad water pump, fan clutch, and e-fan.
what are yalls opinions.

[JackStraw]

anyone else have any thoughts or ideas?

[indept]

Is it leaking out of the weephole in the waterpump or from the pump to block gasket? Also check to see if it's leaking from the thermostat housing gasket or if the top hose or heater hose is leaking down and travelling along the water pump. Hose it off really good then let the water dry and then look for the leak.

[jchoi]

I just changed mine 2 weeks ago, not too bad. Didn't run into any issues except for my brand new tube of RTV being dried out. But I did mine with out removing the shroud, did come out with a few bruises on my forearms but that was nothing. Just relax, take a deep breathe and go at it.