Cruiser Down: Tale of Heater T failure on a 100 series

[BrownAce]

I haven't seen anything about them that shows that Toyota improved on the design. Some folks are putting in brass units. I don't know how they handle reacting to anything in the coolant but can't imagine they are having issues.

The PO of my vehicle had a shop replace them at 100k. I replaced those at 175k (9 years later) and they were still in very good shape (slightly discolored). At 175k I replaced all of the hoses around the T's as well. It looks like these heater T's are just something that should have been added by Toyota to a 90-100k Toyota service interval; but the Toyo engineers likely didn't foresee having this issue.

I pull the radiator and fan shroud when doing a timing belt because it gives me more room and I don't want to damage a radiator over 15 minutes of work and some cooling fluid. I plan to do the heater T's every timing belt simply because it's easy to go the extra mile and do my coolant flush at the same time.

You could also do heater T's every time you do spark plugs.

IMO the plastic holds up great for 10 years, but 20 years is just way beyond what it was designed to do. If Toyota had fiber reinforced the plastic or just gone with metal T's this would have solved the issue altogether.

I'm actually pretty impressed mine were holding together at almost 25yo. Maybe they're actually awesome if you think about it that way.

 

[AlpineAccess]

I'm actually pretty impressed mine were holding together at almost 25yo. Maybe they're actually awesome if you think about it that way.

I'm more impressed with plastic items like the evap solenoid and dash/gauge cluster construction. They last longer without any problems and don't kill my motor when they fail. Those are areas Toyota can use plastics which are non-compatible with heat cycling/silica free coolant.

That being said; Toyota is notorious for using non fiber reinforced plastics (or just plastic in general) in critical areas of cooling systems where they should 100% know better and have used aluminum or brass.

Toyota Land Cruisers; 80's and 100's, 1st Gen Tundra, multiple gens of 4Runner and Tacoma's all have cooling systems with serious vulnerabilities that can lead to engine (overheating/head warp level issues) or transmission failures. Unfortunately these issues largely stem from plastics used that are not sufficiently compatible with the fluids and temperatures they are exposed to.

One of the primary selling propositions for Toyota is reliability and durability; and they do excel in many areas. But its because of that I won't let them off the hook when they make such an obvious screw up.

#brakeboosterrecallplease

 

[BrownAce]

If anyone is curious, All new rubber hoses that connect to both Ts and 2 new plastic Ts were under $100 on partsouq including shipping. Everything was significantly cheaper on there and only $13 shipping from UAE. In my past experiences DHL from Dubai shows up quicker than my local dealership can get stuff.

 

[yj668]

I'm more impressed with plastic items like the evap solenoid and dash/gauge cluster construction. They last longer without any problems and don't kill my motor when they fail. Those are areas Toyota can use plastics which are non-compatible with heat cycling/silica free coolant.

That being said; Toyota is notorious for using non fiber reinforced plastics (or just plastic in general) in critical areas of cooling systems where they should 100% know better and have used aluminum or brass.

Toyota Land Cruisers; 80's and 100's, 1st Gen Tundra, multiple gens of 4Runner and Tacoma's all have cooling systems with serious vulnerabilities that can lead to engine (overheating/head warp level issues) or transmission failures. Unfortunately these issues largely stem from plastics used that are not sufficiently compatible with the fluids and temperatures they are exposed to.

One of the primary selling propositions for Toyota is reliability and durability; and they do excel in many areas. But its because of that I won't let them off the hook when they make such an obvious screw up.

#brakeboosterrecallplease

Plastic thermostat housings in some Yotas are serious engine killers too.

 

[ryanCA]

What is the cost of heater -tee repalcement by that dealer?

 

[okoverland]

What is the cost of heater -tee repalcement by that dealer?

Put your VIN in here:



EDIT: You were talking about the dealer, gotcha.