Pesky Coolant Tee, again so soon (1 Viewer)

[DBULL]

Are you using OEM spring clamps or the screw type?Plastic fittings don’t play well with screw clamps….

 

[OwnerCS]

View attachment 2785649

When I replaced hoses and a cracked heater T, the replacement was a Four Seasons metal Ts. I ordered a set of these Omega Ts to keep on hand should the Four Seasons fail. These Omega Ts will outlast me and the truck. They cost more.. But well worth it.

 

[Sawyer2001LX]

Its not that critical of a component and there are more than enough plastic interfaces in the cooling system that you aren't even aware of

"Not critical"? If that little piece breaks, which it I known to do, your entire vehicle is shut down. I would say that's pretty "critical". How many of those other plastic components are so well known to failure and have had dozens of threads discussing them?

 

[hoser]

Same heater T is used in the 80 series but it is not a common problem in the 80 series though.

The 80 series also came with a brass Tee's. Somewhere along the way, it became plastic or maybe just as a replacement part, I'm not sure.

My guess why the 80 heater Tee lasts and the 100 doesn't? The 80 uses a conventional water heater valve that stops the flow of hot coolant circulating through the heater core(s). So if you stop the flow, you stop the Tee from heating up as much.

On the 100, the hot coolant never stops circulating through the Tee and through the heater cores. They have dampers after the heater core(s) to control the cabin heating. More precision I suppose. The heater Tees are disintegrating fro the inside out.

Now take a look at the 1st gen Sequoia's. Same engine as the 100. No known history of heater Tee problem yet it uses the same exact heater Tees (in RED). However, the heating system uses the "old style" heater valve (in GREEN) which stops the coolant flow.

 

[nukegoat]

"Not critical"? If that little piece breaks, which it I known to do, your entire vehicle is shut down. I would say that's pretty "critical". How many of those other plastic components are so well known to failure and have had dozens of threads discussing them?

Running out of gas stops your whole rig too

 

[flintknapper]

Running out of gas stops your whole rig too

Yes, but you have a fuel gauge to monitor that, heaters tee's sometimes don't show the condition they are in, mine did not. They deteriorate from the inside...out. So unless you have a way to readily bypass them, you'll be pumping coolant out like Old Faithful and be shut down. That's pretty critical in most folks book. Why keep fighting this?

 

[OwnerCS]

The 80 series also came with a brass Tee's. Somewhere along the way, it became plastic or maybe just as a replacement part, I'm not sure.

My guess why the 80 heater Tee lasts and the 100 doesn't? The 80 uses a conventional water heater valve that stops the flow of hot coolant circulating through the heater core(s). So if you stop the flow, you stop the Tee from heating up as much.

On the 100, the hot coolant never stops circulating through the Tee and through the heater cores. They have dampers after the heater core(s) to control the cabin heating. More precision I suppose. The heater Tees are disintegrating fro the inside out.

Now take a look at the 1st gen Sequoia's. Same engine as the 100. No known history of heater Tee problem yet it uses the same exact heater Tees (in RED). However, the heating system uses the "old style" heater valve (in GREEN) which stops the coolant flow.

View attachment 2787319

Speaking of the 100 series design compared to a Sequoia's heater control valve, I haven't seen any air-mix door failures that I can remember.

Do the air-mix door motors fail on 100 series?

 

[nukegoat]

Yes, but you have a fuel gauge to monitor that, heaters tee's sometimes don't show the condition they are in, mine did not. They deteriorate from the inside...out. So unless you have a way to readily bypass them, you'll be pumping coolant out like Old Faithful and be shut down. That's pretty critical in most folks book. Why keep fighting this?

Because Mr. T would never create a poor design. This forum used to be filled delightfully with Toyota cultists like myself. Now it's naysayers

 

[flintknapper]

Because Mr. T would never create a poor design.

You mean like a Starter up under the intake manifold....or a Alternator right down at the bottom of the engine (exposed to every contaminate that can get in around an engine)? Inferior low beams (LC and LX), weak front diff (98-99 models). etc....

 

[Sawyer2001LX]

Running out of gas stops your whole rig too

Yep, I would say fuel is also "critical". Your point?

 

[nukegoat]

You mean like a Starter up under the intake manifold....or a Alternator right down at the bottom of the engine (exposed to every contaminate that can get in around an engine)? Inferior low beams (LC and LX), weak front diff (98-99 models). etc....

Blasphemy

 

[e9999]

going a bit in circles now it seems. Let's keep this thread about Tees please. Feel free to start another tech thread about what is critical failure for the truck or not...