**** 12/30/18...PDF Attachment of instructions w pics added to bottom of second post****

Due to the recent 3GS water pump failures, I decided to be proactive and change mine. I also noticed some dried pink coolant crust under the water pump pulley during my last oil change. My car has 96k miles. On a scale of 1-10 with 10 being the most difficult I number this job a 4. It took me 2.5hrs.

Disclaimer: Attempt at your own risk. This is the method that I found most useful and efficient – yours may differ and may not be the exact as described herein. As with any do-it-yourself project, unfamiliarity with the tools and process can be dangerous. This project should be construed as theoretical advice. *I will not be held responsible for any injury due to the misuse or misunderstanding of this*DIY project.


Here we go:

First stuff needed: water pump assembly (Aisin), 2 gaskets, water pump gasket, idler pulley and new serpentine belt. If you do not drain your radiator, you only need one gallon of Toyota long life coolant, but I drained radiator so I needed every bit of 2 gallons. I bought coolant at Toyota and everything else off ebay.

GATES 36173 Idler Pulley: $30
Aisin WPT-137 Engine Water Pump and gaskets: $93
Lexus Serpentine belt: $23
Toyota Long Life Coolant (2 gallons): $47

Total Spent: $193








Next, disconnect negative battery terminal and remove engine covers. There area couple other basic plastic covers that need to be removed as well.

Remove cap and drain radiator. Use tube for less splash. I placed a plastic bin underneath.









I also removed reservoir, drained and cleaned. Easy – two 10mm bolts.




Remove all hoses from water inlet assembly. There should be 7.






I went ahead and loosened water pump pulley. 4 bolts, all 12mm. The tension on the belt allows you to break loose so you do not need a special tool.




Next I removed the belt. Use 14mm wrench on tensioner pulley, pulling toward water pump pulley – this allows you to free tension and belt. Overall belt didn’t look too bad.






Next I removed the pulley. It was evident I had a leak. Look at the back of the pulley.




Now that I can see the water pump, look at it as well – pink coolant crust.




Next I removed the injector drive. 2 10mm nuts and 1 10mm bolt (underneath – don’t miss this). I then just put it out of the way – no need to completely remove electrical lines.








Next I removed both the idler pulley (already removed in 1st pic. I replaced this) and the tensioner pulley. The tensioner blocks 1 of the 16 bolts that holds the water pump assembly. IT IS REVERSE THREADED - turn right to loosen.








Next I removed the water inlet assembly. A little tricky here. Once you remove the four bolts and nut all 10mm, you need to pull the assembly toward the front of the car. Mine was super tight. The black piece is what houses the thermostat. You can change now if you desire.







Now you can removed all 16 bolts (some 10mm and others 12mm) for the water pump assembly. You will be changing both rubber gaskets on the the water inlets seen in the first pic.

 

Old assembly













Add Loctite to bolts and install new one. Notice new rubber gasket in second pic. Remember there is also another gasket for in the inlet assembly that needs to be changed.








Reverse the other steps to reinstall everything else. Do not forget two small gaskets. Add coolant to radiator and reservoir. I also did not change my upper and lower radiator hoses because they looked fine but you can do this if you think changing is necessary.







Start your car and burp your system. Turn on heater and allow car to warm to where fans kick on. Once coolant is puled into engine, you may have to add a little more coolant to reservoir.

 

very nice. I will be on this once I get my recall done this coming week. good timing

 

Do you have a pic of where the drain bolts are on the block?

 

Sorry man i dont. I have a crappy nikon coolpix 5mp camera i use for the DIYs because i dont care if it gets dirty. Unfortunately i couldnt zoom in enough to get a good picture.

 

Very nice write up, this should help make it easy on others to tackle the job themselves

 

Thanks i saw your thread. If i missed anything feel free to add

 

I have a YouTube video out there that might help anyone too. Just look up my screen name on youtbe

 

Great write up! Any signs of failure before taking anything apart? ie burning coolant smell or spots on driveway etc.? Does anyone know if this is this a common failure on the GSh as well?

 

Thanks. The biggest sign of failure is leaking coolant. Toyota long life coolant crystallizes when it contacts the air so most likely you will not see it on your garage floor but you will see the coolant level in your reservoir drop some. Also some people hear clicking sound from engine - this is coolant leaking on timing chain. If you see a few pics above you can tell mine was leaking. Not sure about your GSh question but there are a couple threads where members are posting their failed pumps.

 

yep, just did mine yesterday. The easiest water pump to replace I've seen. less than 2 hours. The thing was leaking and the weep hole was pink. Good to go now. replaced idler pulley, thermostat, both hoses and belt along with the pump.

 

How many miles do you have and how did your belt look?

 

86,000 and I swear the belt looked so new that I wrapped it up with a rubber band and stuck it in the trunk for emergencies.me or someone else along the way.

 

Yeah man i was shocked how new mine looked. These cars are sooo easy on belts.

 

seems like water pump failure is common in lexus cars. not just the GS.