How to Replace the Inverter Coolant Pump

Just changed the inverter pump with an aftermarket pump from Amazon for $58 on a 2005. Cannot tell the difference from the OEM and it fits perfectly and quiet. Was changed in the original recall before. Failed this time at 231,300 miles. I found following the service manual of removing the bumper and headlight lens was very simple and the best approach. Since this was the first attempt it took 90 minutes to determine how much of the bumber needed to be flexed out which required removing more screws, so the lens slid straight out. I estimate that if I had to do it again, it would be under 45 minutes. Removing of the pump and hose and placing the hose back on the new one on and tighten took about 15 minutes. No struggling to get in tight spaces.

 

I just did a 2005.

RockAuto dorman pump w/2 day ship was $80 and local dealer 1 gallon coolant $28 (oreily auto parts wanted to sell me "asian coolant" for $18 but the label did not say sllc and the clerk saying "it should work" was not a confidence builder).

I wish I removed headlight for easier access. My job took 2hrs. Had to fish the pump out towards the center hood latch and pinch the radiator hose pretty hard to clear an exit. Passing new pump in was an equal pain. Popping the fuse cover cave me a little extra room for the electrical connector and loosening the top mount of the inverter for better access.

What slowed me up was getting the pump re-primed. The youtube videos were right to go into accessory mode (start button twice no brakes) and listen for a small whir like aquarium pump. I knew it had juice just no flow. I had to repeatedly flex the upper hose from reservoir until it burped and i could hear the pump passing fluid. I had some scrap tubing on hand so i was able to bleed the air from the valve and wrap up. For funnels - i always cut the bottom off a 2 liter soda bottle for single use.

 

Any advice on which oil additive products to use for this.

 

Did I just put myself through inverter coolant heck? Gurus: Other than doing all the work yourselves, what would you have done differently?

- Eight weeks ago as preventive maintenance at 106,000 miles I had a nearby dealer replace the coolants in both loops (engine and inverter+transaxle) for $330, including an oil change. All seemed well with no subsequent burbling or topping off needed in either coolant loop.
- Three weeks ago the A/C started consistently failing after running for a few minutes. Diagnosis found a small leak in the evaporator including a tell-tale trace of refrigerant oil coming out of the condensate drain. I did not ask to see the leak myself. The service writer stated that low refrigerant could cause the A/C compressor to overheat and shut down without setting a failure code. I had them replace the evaporator and drier and exp valve ($1880). All again seemed well.
- Yesterday on a road trip the inverter coolant pump died, setting code P0A93. By chance we were very close to a different dealer who replaced the pump while we waited ($620). No problems on the way back, and again no topping off needed.
- Today I read a Facebook note by Kaveen's Auto Clinic that the A/C compressor stopping after a short time can be a symptom of a failing inverter coolant pump without necessarily setting a code. [I tried to include a link to that Facebook posting here but this tool doesn't seem to allow it.]

It could all be unfortunate coincidence. Replacing the evaporator etc. did fix the A/C problem. If the inverter coolant pump were the root cause then replacing the evaporator etc. would have had no effect. The inverter coolant pump death might have been caused by an error in replacing the coolant, but OTOH a pump failure after 14 years and 107,000 miles is not surprising.

 

2009, 125k on odometer, P0A93 code thrown, it was 110 out. Able to nurse it home. Thought it might be battery, reading was low. Able to do some trouble shooting after work, 11 pm, saw inverter temps spiking at 190, but reading 14 volts. Ordered new pump, will install tomorrow when it gets delivered. Will remove headlight. Thanks for the info. Will update on how it goes. There's videos on YouTube showing procedures. May get clamps for tubing.

Z981 ?

 

Part arrived. 20 minutes to install, hardest part is getting the bolt that is on the side of the bracket that is on top of the pump mount. A little twist on the tubing and it slides right off, the fluid on the hose makes it easy to go on. Glad I was able to save some money. Got everything buttoned up look out for a drive, engine got to operating temp 185, high I saw on inverter 1 was 147, and inverter 2 was 140, using torque. I'm a happy camper.

Z981 ?

 

Thanks for the info. Moving the headlight made it an easy install. Definitely worth doing considering the shops around me were quoting around $900 for it. Pinch off pliers for the hoses would have made it even easier but I guess 30 mins in total isn't bad. Most of that was looking for where i placed the coolant tank cap after adding coolant (ended up being right next to the tank, just couldn't see it....).

 

So pretty sure I am going to have to do this. What is difference between genuine Toyota and any of the ones I see on EBAY etc, will they all work the same? As for the coolant, looking up the SLLC coolant on google brings up valvoline etc coolant that appears to be compatible, will that work fine?

And finally and most important, I'm not an idiot and I've worked on cars a fair amount, is this considered a relatively simple job? From reading about it, it doesn't look any more difficult than changing a car thermostat?

 

I saw a video about being able to do this without changing the coolant. Has anyone done it and can I clamp off the hose with a common tool around the house?

 

Yes I used a basic c-clamp had some canvas I wrapped around the hose to protect it a bit.

 

Do you have to clamp off one hose or both of them? It looked like in the video I saw that they just clamped off one hose.

 

Tackling this tonight hopefully. Pump is here. I plan to clamp the hoses off with vicegrips, obviously with something wrapped around the hose between the vicegrip and undo the 3 screws if possible and remove from the plate to screw into the plate that is already in the car as recommended in this thread.

 

Clamping off was a pain. I'm getting hose clamps if I ever do something like this again. I tried doing it by switching just the top unit but one of the 3 bolts was impossible to get so I did it with the full plate. It was tricky to get it out and back in but not impossible. I moved the inverter over slightly. Hopefully no more issues

 

Yes you would need a cheap set of plastic hose clamps for $10. How did you do it without it?

 

I used vice grips with padding. Bleed screw is frozen. Any other way to bleed?

 

Put your wrench on it, then strike it with a hammer.

 

won't that break it. I didn't want to twist harder with the socket wrench as clearly the bracket was bending and the nut was not moving.

 

With previous cars (all Hondas) I've always opened the bleed valve during the intitial fill. You can feel air rushing out as you pour in coolant. Then, when coolant starts coming out of the bleed valve, quickly close it.

Any reason to not open the bleed valve during the initial fill?