Please help….what is this part number?

Here’s part of a better version of the illustration, which is from the Repair Manual (more info) for third-generation Prius cars, under Engine/Hybrid System: 2ZR-FXE Cooling: Coolant (For Engine): Replacement:



The air release valve is part of the No. 1 Water Joint, part number 87251-47020 (formerly 87251-47010), shown with part name code 87251D in catalog Figure 87-16, Heating & Air Conditioning - Water Piping.

 

In some Gen 3s, that tee includes an air release valve, and in some it doesn't, and I'm pretty sure when I looked for a corresponding part number change I didn't find one. It seemed as if they had kept the part number the same, and just dropped the little valve from it. Maybe I missed something, but that's what I remember from when I looked.

 

I think 2010 for sure has the air release, but at some point further on that function was removed. I'd guess 2012 but not sure.

 

Right, I'm pretty sure I remember looking up the part number for that tee in both of those years, and maybe some others, and the same part number was shown in all cases. That led me to think they had simply changed how the part is made.

 

Which kinda breaks down the concept of part numbers tied to unique parts. Same story with that revised booster pump, and it’s rotated label the only differentiation.

 

That’s a good point: the Repair Manual for model year 2010 is the only edition that mentions the air release valve in the coolant replacement instructions. For 2011 and later, it’s not shown or discussed.

The Electronic Parts Catalog shows the part number for JOINT, WATER, NO.1 changed from 87251-47010 to 87251-47020, starting with November 2010 production, and for all vehicles, part number 87251-47010 was superseded by 87251-47020, effective October 2012.

 

Thanks for checking that. Did you notice if the later editions add any new step in place of using the old air valve? Or did they simply find that filling to B on the degas bottle, capping, and running the engine up to temperature and pressure for several minutes, was enough to do the trick?

 

The procedures for model years 2011 and later also omit any mention of the cylinder block drain cock plug, but they don’t have any new steps for air bleeding, only the instruction to “Squeeze the inlet and outlet radiator hoses several times by hand to bleed air from the system,” which appears in all versions.

 

I opened that, got maybe 1/4 cup coolant drain.

Hard to get to, too.

 

I don't think it works like that. There were two styles of joint, one with and one without the air bleed function.

Per @ChapmanF (in post #5): it seems like Toyota just revised the part, took out the air bleed function, and retained the same part number. Which is a surprising approach, likely to lead to confusion. At this juncture, if you want that bleed valve, best bet is likely a scrap yard.

FWIW the bleed bolt seemed effective when I was filling: I could feel air exiting as I poured, and eventually coolant started coming out. No clue why they would want to remove that function.

You could add your own bleed valve. Or...: when filling up fresh coolant, just leave one of the hoses at that tee disconnected, till coolant starts coming out, same thing.

 

Ok, I think I'm cluing in: you have the old style of junction, which should include the white screw cap, but that cap missing? What year is this by the way? Your avatar's an '08.

 

I think short of finding one in a scrap yard, you'll have to buy a complete junction, and it won't have the bleed screw functionality.

Again, you can just pull off a hose to air bleed when filling. Definitely not as convenient though.

Did you just lose it, drop it or something?

 

Yes, immediately.

If you dropped it into the engine bay, it's there, somewhere. Have you got the engine underpanel completely off? It could be lying atop it.