A tale of two heater T's (1 Viewer)

[bloc]

I got my truck with 105k on it, and dropped/filled the coolant at 120k. At the time I took a look at the heater T's and they were perfect. Between this and not hearing much about T failures I assumed toyota fixed the problem from the 100-series.

Then I see a few posts about people having them pop near 150k, with clear pictures of degraded plastic. But going from the condition of mine to something that would fail within 25k seemed odd...

So now with 175k on the chassis I got nervous enough to buy the parts and plan to change them as PM. So today I get it apart and.. mine are still as-new.

I'd like to know why there is such a wild swing on these parts. Are some degraded from significant amounts of towing? Warmer ambient temps? (mine has had 70k in central texas)

For those of you that have had failures, please post pictures and mileage that it failed.

 

[linuxgod]

I don't think towing matters. The coolant temps aren't that different. My A/T temps and engine oil ran around 212F on our 2500 miles out to Maine and back last week, but engine coolant was 198-202F the whole time, even with ambient temps around 90F. That was towing in 4th or 5th gear. Ambient coolant temp when not towing is 196-198F for me.

That said any ideas I have about why some people experience this failure and others don't is pure speculation on my part. FWIW I've got 126k on my 2013 now and so far mine haven't given out (though my radiator got the dreaded crack around 76k miles).

 

[bloc]

Good data about towing temps, that would seem to rule it out as a cause.

Maybe some of these parts are coming from different sources for the two different factories cruisers are produced in? I haven’t paid close enough attention to whether the failures are early build or late.

 

[linuxgod]

My data is anecdotal of course. It's just that I'm fairly obsessive about monitoring things. I have an IT systems background and so baselines and monitors are pretty much required unless you want to troubleshoot via the seat-of-your-pants.

I'd be curious what the part #s are on earlier LCs and whether they've been superceded. Could certainly be the factory/supplier the parts came from. Could be something else entirely - i.e. subtle change in Toyota coolant formulation, or maybe cooling system pressures, or the impact of air being trapped in the system near the T's (which doesn't cool as well as antifreeze/water).

I plan to do mine whenever I eventually need to do the water pump... not that they're related, except for the effort to drain the coolant.

 

[gaijin]

All I can offer is a hunch - we'll see if those who report failed T's can back it up.

My hunch is that in those vehicles with failed T's, somewhere in that vehicle's history something other than Toyota SLLC was used. Due to some incompatibility issue between the T's and the non-Toyota coolant, the plastic/resin/polymer of the T's was degraded resulting in failure.

The temptation is strong to use something cheaper than Toyota SLLC, and there are several non-Toyota coolants on the market that purport to be Toyota compatible; but are they really? My hunch is that they may not be.

Of course, if a vehicle is purchased used, it is very hard to absolutely confirm something like coolant history, but sounds good to me - as a hunch.

HTH

 

[linuxgod]

All I can offer is a hunch - we'll see if those who report failed T's can back it up.

My hunch is that in those vehicles with failed T's, somewhere in that vehicle's history something other than Toyota SLLC was used. Due to some incompatibility issue between the T's and the non-Toyota coolant, the plastic/resin/polymer of the T's was degraded resulting in failure.

The temptation is strong to use something cheaper than Toyota SLLC, and there are several non-Toyota coolants on the market that purport to be Toyota compatible; but are they really? My hunch is that they may not be.

Of course, if a vehicle is purchased used, it is very hard to absolutely confirm something like coolant history, but sounds good to me - as a hunch.

HTH

Or maybe it's the opposite and this happens because people don't change their coolant at which point it eventually degrades?

 

[bloc]

I plan to do mine whenever I eventually need to do the water pump... not that they're related, except for the effort to drain the coolant.

Just for info, the stock T's are only available with the whole hose assembly. Somewhere on here I dug up 87248-08030 which I confirmed will fit, though they have slightly different mold marks

There are a couple different clamps in that location but 96136-42501 is one of them. Should work in all locations on those hoses.

 

[04UZJ100]

Or maybe it's the opposite and this happens because people don't change their coolant at which point it eventually degrades?

Glycol based coolant doesn’t really degrade. It’s pH changes over time which is why the intervals for replacement are there. It’s heat absorption capacity does not decrease over time unless contaminated with oil/combustion byproducts etc.

 

[kcjaz]

My data is anecdotal of course. It's just that I'm fairly obsessive about monitoring things. I have an IT systems background and so baselines and monitors are pretty much required unless you want to troubleshoot via the seat-of-your-pants.

Pretty sure the IT guys at my company use the “seat-of-your-pants” method.

 

[bloc]

Bump. Still interested in data from people that have had failures.

 

[onelittlestar]

Being a new LC200 owner of a rig that just cruised past 200k miles, this is something I'm interested in. PO stated the radiator was replaced and it certainly looks like it has been, would these have been replaced at the same time? I do not have records unfortunately, though all the work was performed locally here in Houston area and I suppose I could try and hunt them down.

 

[CharlieS]

Not likely that they replaced the Ts with a radiator job.

 

[TexAZ]

i had both "T's" fail at 250K. nothing but toyota coolant until the first one failed on the way home from work. had to put generic in to get home.

not enough left to photograph. round hose portions pretty much turned to mush.

i do tow a boat several times a year, and live in AZ where the temps are middle east hot.

 

[onelittlestar]

thanks for this, just ordered replacements

 

[crussell3234]

Can someone post a link to buy replacement T’s

 

[bloc]

Can someone post a link to buy replacement T’s

87248-08030 For just the T from toyota.

 

[onelittlestar]

Amazon Heater T

 

[CharlieS]

I have a pair of metal Tees and breeze constant tension clamps on the shelf for when I get around to it.

Dorman help 56387. Not positive these are the right ones, but I picked them up based on a prior post.

 

[yellowgeko]

I have a pair of metal Tees and breeze constant tension clamps on the shelf for when I get around to it.

Dorman help 56387. Not positive these are the right ones, but I picked them up based on a prior post.

View attachment 3103358

Did you ever verify if these are correct?

 

[TexAZ]

I used one of those and it has held. I did switch to heavy duty worm drive hose clamps, after another member said the Toyota ones leaked with the new style T. I also used a garden hose barbed T from home depot while I was waiting on the dorman parts to come in. It was a pain to get to work h
But held up really well.