Went to a map torch (much hotter) and managed to remove this bolt - very painful to get to this point. The bolt size is m8x1.25x25mm. for this particular application (ie. into the thermostat housing) is there a particular grade/type of bolt I could be using so that I don't have similar problem again. Looks like my options are a zinc plated carbon steel 8.8 or I could go with a stainless steel 18.8 (a-2). Is one going to be any better than the other based on the material it is going into? The use of anti-seize is a no brainer I guess (I have the copper based one - do I need to go aluminum based?). So many questions/concerns about a stupid bolt but given what I went through I want to do the absolute best option. Also, is there supposed to be a gasket under the thermostat housing? There wasn't one - perhaps that's why the bolt became so seized.

 

No gasket, rubber O-ring on the thermostat.
Any bolt strong enough for the torque spec should work.
Yes on antiseize, “220, 221...whatever it takes.”

 

i thought i had seen somewhere there was a paper gasket but maybe not. what about some of that grey matter? without a gasket I can see how that bolt got so darn stuck - could have been some coolant going down the bolt hole. Can't find the torque spec anywhere.

 

If you do find a torque spec, i’d bet it’s not more than 12 lb/feet, so just tight using one hand on the ratchet.

 

Best answer yet. lol.

 

Now your over thinking it...
No gasket. Don't over tighten the bolts...
Somethings require a torque wrench...
others require a little common sense.
Good and snug will work great for the thermostat housing...a little copper coat on the threads if you'll sleep better.

 

shows my age. I was 16 when that movie came out.
There used to be a company called “show power” that provided generators for big rock shows where the power coming off the street couldn’t support Motley Crue’s light show, for example. They had tshirts with that quote printed on it. Always wanted one!

 

Picked up a new thermostat (Gates) - it hardly looked much like the one I took out when I compared them. the one i took out had the name Kuzeh on it - sounds like a Japanese name, I wonder if it is the one Toyota would put in. I ended up ordering an Aisin from Amazon instead of using that strange looking Gates unit. Anyone happen to know if the one toyota themselves use is this Kuzeh brand?

 

I use the Toyota 90916-03070 thermostat. It's about $35 but it's the dual stage thermostat which a Toyota TSB said would fix the temperature gauge overshoot. I used to have the overshoot and now I don't.

 

I just looked at 22RE Performance's website.

They sell the Genuine Toyota thermostat for the 22R series engines; the same part that you would order from your local Toyota dealership.

In their picture on their website, you can see that Kuzeh and the "old school" Toyota logo (TEQ) are stamped onto the thermostat.

I am not sure if the Gates thermostat you bought looks the same or not, but it is made by the same company that Toyota uses.

 

I would say I use about a half a grunt with one hand. Doesn't take much.

For the antisieze, I would positively use the aluminum stuff. What you're applying it to, well , the threads anyway, are aluminum. You want to try to avoid differential metal corrosion wherever possible.

I definitely use the two-stage Toyota thermostat. Absolutely eliminates the temperature overshoot. Always get a new gasket to go with it. Makes sure it's sealed up well, so you don't get water into the bolts.

Use the Toyota Red coolant, too. It's made for the engines Toyota uses. The steel block, and aluminum head, will corrode badly with the regular green coolant. The Toyota Red helps reduce that differential metal corrosion problem a lot. Clean, flush, and replace the coolant every few years also helps stop the corrosion, or at least reduce it a lot.
Keep the hoses in good shape, too. No soft spots, bulges, and so on. Very important. I just change them when I change and flush the system. As with the belts I change once a year, I keep the used belts or hoses I remove in the back, when I put new ones on. That way, if something fails on me, I have a spare I know is good with me, so I can put it on quickly, wherever I am.

Good luck to you!
Pat☺

 

i believe you misinterpreted the OP's statement; ie, the gates t-stat looked nothing like the t-stat with kuzeh stamped on it that was removed from the vehicle to be replaced with the gates.

 

Thats a pretty cool (if you will parden the pun) thermostat. I asked my local Toyota dealer about it today. He said $75 and they would need to have it shipped from california (to Canada). So I am just going to put that Aisin stat in and see how it goes. If there are any problems I might just splurge for the one you suggest.

 

Yes, you are right. Whoops....

 

NAPA Altrom made by Tama are good quality thermostats, and they are made in Japan too. All my local NAPA stores keep them in stock.


https://www.napaonline.com/en/p/ATM1...put=thermostat

 

Thanks

 

Thanks. Yes, I always use Toyota Red. Interesting about the hoses... this is 1990 and I believe the hoses are original (I have no record of them being replaced). I bought new Gates hoses thinking I would put them on. But you know, the quality of these original Toyota hoses is obviously so far superior because even with their age there is technically nothing wrong with them. They are uniform and no bulges and no issues at the ends etc. If I chuck them and put the Gates on I will probably be replacing them in a few years.

 

For the anti-seize I see my shop has the permatex copper or permatex silver - no permatex aluminum. Although they do have small packs of anti-seize lubricant (theoretically marketed for spark plugs as per the picture on the pack). It indicates a blend of aluminum, copper and graphite. Perhaps that will be ok.

 

In my opinion, they all work the same and you're overthinking it. You're already a step ahead just by choosing to use anti-seize.

OEM hoses are still available and what I used for replacements.

I use plain green coolant. It's available at every gas station should I need some, although I generally try to keep my truck well maintained. The Toyota red has been reported to weep through gaskets more easily than green. They were still using green coolant from factory when my truck was built.

 

I agree with Alex and I think paying more than $15 for any thermostat is too much.
BUT, I will say that in the 90’s when i was deep into 80’s Toyotas i observed ten year old original thermostats on 80’s Yotas giving up, leading to headgasket failures. I even got a car or two free after overheating and warping the head. So #1, don’t expect your thermostat to go 10 years or 100k miles, and 2, if you don’t know its age just replace it as cheap insurance. It doesn’t only apply to Toyotas.

We had Tercels, Corollas, Celicas, an ‘84 4runner and a brand new 1986 4x4 Extracab sr5 in my family. If they had 100k-125k miles, it was the thermostat, alternator brushes, or starter contacts that would shut down a Yota.

And i’m not the highest mileage driver here by a longshot but have always used Prestone coolant with good results. Red did not exist in 1986.