How to Replace the Water Pump on a Jeep Wrangler JK

Chris

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A bad water pump on any vehicle is a sign of impending doom. If your Jeep Wrangler has a leaky or a bad water pump, don't get yourself stranded somewhere, replace it as soon as possible. A water pump that is not working optimally is not cooling your engine as it should. While it may be driving okay, don't let that fool you into thinking that nothing is wrong. Your engine will be running hotter and harder than it should, which will lead to faster deterioration and wearing out of vital engine parts. This all leads up to a major repair bill, so while you may be trying to stretch it out for as long as possible, in the end, it will cost you much more. Replacing the water pump on your Wrangler is not nearly as hard as it sounds, and if you choose to do it yourself, you will save a boatload of money from having a pro do it for you. If you are just not sure of yourself, be sure to get quotes from several different shops to get the best price possible.

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Materials Needed
  • 3/8 inch drive ratchet with 10 and 13mm sockets and extensions
  • Pliers
  • Phillips head screwdrivers
  • Catch basin
  • Torque wrench (105 ft/lbs)
  • Replacement coolant (50/50 premix or regular plus distilled water)
  • RTV sealant
These instructions do not include the optional step of completely draining your antifreeze. If it has been a good long while since you replaced your coolant, you may want to take the extra time to flush your cooling system and replace your coolants. Otherwise, the job is fairly quick and you will still have to top off a generous amount of coolant from the loss when you pull the water pump.

Step 1 – Disconnect your battery
It is good practice to always disconnect your battery before working under the hood, especially when you are removing belts.

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Figure 1. Always disconnect your battery when working in the engine compartment.

Step 2 – Remove the serpentine belt
Using a long handled ratchet, or a ratchet and breaker bar, insert the ratchet bolt into the square hole in the tensioner pulley. One it is inserted, push down and to the right until there is slack in the belt. Slip the belt off over the alternator pulley and then slowly release the tensioner pulley back into normal position. The belt is now slack enough that you can remove it from the rest of the pulleys. Now is a good time to give that belt a thorough inspection and replace if at all worn.

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Figure 2. The tensioner pulley will be just south of the alternator pulley and have a square hole dead center.


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Figure 3. If your belt has cracks in it or shows signs of glazing, go ahead and replace it now.

Step 3 – Remove the water pump pulley
Once the belt is off and out of the way, loosen the three bolts on the water pump pulley. In order to keep it from spinning, use a ratchet strap (optimal) or insert a narrow gauge screwdriver into the smaller holes on the pulley to hold it still (not ideal) while you wrench on the three bolts. Once each is loosened, they can then be easily removed. Once the pulley is off, you'll have access to the water pump.

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Figure 4. Remove the three bolts holding the water pump pulley in place and then pull it straight off.


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Figure 5. With the water pump pulley removed, you'll have easy access to the water pump.

Step 4 – Remove the water pump
There are seven 10mm bolts that mount the water pump to the engine block. These are steel bolts and the block is aluminum, so take care that you don't bust the bolts or rip the threads. You may want to use some penetrating spray on them first and give them a good rap with a hammer. Carefully remove each bolt with your ratchet and 10mm socket. The water pump should pull right out. You will have some coolant spill out, so have your catch basin ready and immediately clean up any spills. You will need to use a plastic putty knife to clean the mounting surface of old gasket residue.

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Figure 6. Start removing each of the seven 10mm mounting bolts.


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Figure 7. Six of the bolts will be easy to get to; however, one is partially obstructed by a pulley and will be a bit more difficult to remove.


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Figure 8. Water pump removed, and this mounting surface needs to be cleaned and smoothed.

Warning
Engine coolant is nasty and toxic to animals, so clean up any spills and dispose of the old stuff responsibly.

Step 5 – Replace the new gasket
Put some RTV sealant on the mounting area of the engine block. If you do use RTV, you will need to let the curing time pass, which is normally about an hour, before you start your Jeep back up. Make sure that the gasket lines up perfectly with the bolt holes. You can mount the gasket to the pump itself or to the engine block, whichever is easier for you.

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Figure 9. Attach the new gasket to the water pump and use a nice bead of RTV sealant.

Step 6 – Install new water pump
Insert the new water pump and gasket into place and replace the seven 10mm mounting bolts. Snug them tight and then put a torque wrench on them. They should each be torqued to 105 pound/inch (9 ft/lbs).

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Figure 10. Reinstall the new water pump and torque each bolt to 105 pounds/inch (9 ft/lbs).

Step 7 – Replace water pump pulley and serpentine belt
Replace the water pump pulley onto the water pump and hold it in place with a ratchet strap. While holding the strap tight with one hand, tighten the pulley bolts with the other. They just need to be tight, but not torqued. Once the pulley is back in place, start snaking your new serpentine belt according to the correct diagram until you just have the alternator pulley to contend with. You'll need to put your ratchet and breaker back back onto the tensioner pulley to create enough slack to slip the belt back over the alternator pulley. Once it is in place, slowly release the tensioner pulley back into position.

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Figure 11. Use a ratchet strap to hold the pulley in place while you tighten each bolt.


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Figure 12. All belts do not route the same. Be sure to follow the correct routing for your belt and your engine.

Step 8 – Top off your coolant levels
Whether or not you chose to drain your engine coolant, you will have lost a ton of it when you removed the water pump. Be sure to refill to the correct level and check and recheck before taking off. Always use distilled water when mixing if you did not purchase the pre-mixed solution. Replace your battery cable and start her up (after the curing time has passed). Let it get to operating range and re-check the coolant levels.

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Figure 13. The use of a no-spill funnel makes topping off your engine coolant a nice clean proposition.

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