[APosguy]

This issue has been posted before, but since it's a potential engine killer I thought I'd mentioned it again.

Returned home and smelled coolant on my 09 Sienna LE with 208k miles. Pop to the hood to hear phft, phft, phft and could see coolant leaking from below the air intake hose between the throttle body and air filter housing.

I'm lucky I didn't have a catastrophic failure causing the engine to overheat.

Remove the battery, air filter housing and intake hose to the throttle body, that gives you plenty of room to replace the faulty tee. I replaced both plastic tees with the 3/4 inch brass barbed tees. I reuse the original hose clamps and the hoses were in great shape it was just the tees that crumbled.

Joywayus 2Pcs 3/4" ID Hose Barb, Tee T 3 way Union Fitting Intersection/Split Brass Water/Fuel/Air https://a.co/d/efdfa6G

Both plastic tees crumbled as I was removing them, the replacement was long overdue. You also need to be careful removing the broken part of the tee from the hose, you don't want any of those plastic parts to fall into the hose. It was a pretty easy repair, all fixed within an hour.

The tee which has turned brown was the one that failed.

Now to get the mental strength to replace the passenger side axle, air hammer and sawzall on hand.

 

[sixto]

Are those original equipment fittings?

I’m going to have to check if first gen Siennas have metal fittings.

Use the biggest Sawzall with the toughest blade you can find. That is a miserable, miserable job with the cheapest Harbor Freight Sawzall even with a quality blade.

I have been cutting for 30 minutes!

Sixto
‘04 LE FWD 199K miles

 

[APosguy]

Yes, original plastic tee fittings.

Not what I wanted to hear about the sawzall. Just got a mechanic's stethoscope to be sure before I attempt that axle. I'm hoping it's the wheel bearing, but I really don't think so. It's not making the normal bearing noise stays the same on turns, with or without giving it gas, with or without brakes. I'm pretty confident it's the carrier bearing, I hope I'm wrong.

 

[sixto]

In our case it was a wobbly inner CV joint. No noise but vibration during acceleration peaking between 40 and 60mph.

The solid outer shaft takes forever. The hollow inner shaft goes quickly.

Sixto
‘04 LE FWD 199K miles

 

[BillG]

Yes, original plastic tee fittings.

Not what I wanted to hear about the sawzall. Just got a mechanic's stethoscope to be sure before I attempt that axle. I'm hoping it's the wheel bearing, but I really don't think so. It's not making the normal bearing noise stays the same on turns, with or without giving it gas, with or without brakes. I'm pretty confident it's the carrier bearing, I hope I'm wrong.

Do yourself a favor. Pay someone else to do it. If I had taken my van in to have someone else do it, I would have paid roughly $300-400, part included. Instead, I bought the part, spent 9 hours of a beautiful Saturday and 5 hours of a beautiful Sunday before I finally gave up and had it towed Monday morning, had to walk 45 minutes to and from work, and then to work the next morning (they had to wait for a new bracket), and paid $210. It has the added bonus that, if it IS the wheel bearing, they'll diagnose it. You won't spend all your time replacing the half-shaft only to find the noise still present.

 

[supra129]

Who else has done this and what area of the country are you from? I should of done this earlier this summer when I did the rear spark plugs and coils since I had the air box and throttle body off. Maybe I don't need to since I live in the midwest? Does this affect vehicles in southern states only?

 

[sixto]

I don’t think plastic fatigue is the result of ambient temperature and humidity. More to do with age and operational heat cycles. Possibly inconsistencies in fabrication processes. Even with 6-sigma practices 3 or 4 defects per million sneak through.

Sixto
‘04 LE FWD 199K miles

 

[paul r]

I renewed mine earlier this year when I did a coolant flush as a preventative measure and I am sure glad I did. One of these Ts actually broke quite easily when removing the hose. The discussion is here. 06 with 197k miles then. Miami FL.

Coolant change 06LE 3.3L, 3MZ

I removed the thermostat to flush the cooling system for my 06LE with 197500 miles April 10th 2022. I used distilled water and performed a series of flushes till the system ran clear , hopefully removing most if not all of the incorrect Toyota red coolant that I added to the system over the...

www.siennachat.com

 

[floridanative]

What are folks’ thoughts on being able to replace these without draining the coolant, losing a lot of coolant or making a big mess?

I have 182k miles on the originals and am going to replace them at 200k at the next coolant change, but I’m leaving soon on a 6000+ mile trip, so thinking I might want to replace them now in my driveway versus on the road (I have a couple brass ones that I’ll have with me if I decide to wait and will take a gallon of coolant with me).

Thanks,
Mike

 

[sixto]

You should be able to clamp the coolant lines to minimize coolant loss but I wonder if there’s room for 3 clamps at a time.

Sixto
‘04 LE FWD 199K miles

 

[ericreyn]

I am going to do this soon but I feel something like this would be better than the air hose tee that uses a hose clamp. I am sure both would work but the oem,s use the style shown in the link on all coolant hose fittings for some reason or another. Does anyone have any thoughts on this ?

 

[thetut]

Is anyone concerned about the temperature specification of the brass tee. Temperatures range from -40 to 160 F.

 

[ericreyn]

Interested catch, I didn't notice that. Yellowknife and other towns could see both of those temps.

 

[thetut]

Interested catch, I didn't notice that. Yellowknife and other towns could see both of those temps.

Is that ambient temp or operating temp?

 

[sixto]

Isn’t brass good to at least 230*C operating temp in dry air? Is 160*C of coolant a harsher environment? Maybe there’s different specs for a valve with moving parts vs a static fitting.

Sixto
‘04 LE FWD 199K miles

 

[ericreyn]

Is that ambient temp or operating temp?

Both, the operating temp. Is above, and the possable lows could get close to the ambient.

 

[ericreyn]

Isn’t brass good to at least 230*C operating temp in dry air? Is 160*C of coolant a harsher environment? Maybe there’s different specs for a valve with moving parts vs a static fitting.

Sixto
‘04 LE FWD 199K miles

Don't know off hand , but I would have a hard time believing they wouldn't work fine in a auto cooling system. And I think is said 160 F on the top, 160 C would be much hotter.

 

[floridanative]

Is anyone concerned about the temperature specification of the brass tee. Temperatures range from -40 to 160 F.

No, I am not concerned. I believe 160F is a generic rating based on the upper limit of home hot water systems. Manufacturer’s engineers: “yep, it will withstand 160F no problem.” Boom, it gets a 160F rating.

I personally feel that the brass will be more resistant to heat and potential leaks at 250F than plastic. We shall see, I guess.

-Mike

 

[sixto]

Thermostat isn’t open at 160*F

Sixto
‘04 LE FWD 199K miles

 

[floridanative]

Thermostat isn’t open at 160*F

Sixto
‘04 LE FWD 199K miles

The brass Ts are marketed to home plumbing systems which are not expected to reach over 160F. They are not marketed towards automotive uses, hence @thetut’s question. The manufacturers guarantee 160F because that’s what their market demands but they have not been tested to see what their true upper limit is.

-Mike