Thermostat Removal and Installation Tips and Tricks???

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CornbreadJR

CornbreadJR

10 Year
Joined
Apr 25, 2013
Threads
21
Messages
131
Location
Woodinville, WA
Hello all,

With a new thermostat on the way, I thought I'd do the work myself (perhaps under watchful eyes) and wanted to know what to look out for when doing this???

I researched here and found there's been some trouble with the housing and holder breaking or shearing off. When I spoke to Beno just now he said the housing and bolts are aluminum (SHUCKS! Forgot to order a set of new bolts too). Regardless, I prepped the bolts themselves yesterday with some penetrating oil in hopes that if there is corrosion - that by the time I do this, it'll be easier to remove them.

I know the gasket(s) go in a correct way too. Is this noticeable? I didn't find pictures that are clear as to orientation when replacing.

So, since I've had some BAD, BAD luck so far with this truck since purchasing it almost a year ago, I want to be prepared. I could list all the cliques here about luck, prevention, etc. but we ALL know them....right?

Thus any help/advice for a non-mechanic of Toyota's on this simple task would be appreciated.

Best and cheers,
James
 
One thing you might consider is replacing the water pump along with the thermostat. While this is considered mission creep ("while I'm in there fixing this problem...I might as well go ahead and fix this too, even though I don't know if it is broken..."), and is common working on these trucks.

But, in your case, where you have recently purchased the vehicle, are new to wrenching, and still haven't identified the problem you are trying to fix, it might not be a bad idea.

The tradeoff for the extra money is: learning about your truck and having piece of mind knowing that at least those parts are working

You can add on new hoses that attach to the water pump and maybe new belts (keep the old ones - throw them in the back of the rig for emergency).

But, if you want to go one step at a time, that is fine too. Just remember, after you have replaced the parts and refilled the radiator, don't forget to burp (every time you break a line open in the cooling system). Either fashion your own funnel with a funnel and duct tape, or purchase one online that will fit onto the radiator inlet.

Good idea to have a buddy there with you.
 
Thermostat Installed.webp


Here, if you've already decided to open the thermostat housing and replace the thermostat in order to: see what is going on in there and check for cracks in the housing...before moving on to other things (like the water pump and hoses and such), then that is fine. Easy enough to do.

Just remove the four bolts on the housing and lift of the top part of the housing. Don't even need to drain the radiator.

Just when you reinstall the new thermostat:
1) make sure it is installed right side up (the picture below shows it installed the correct way - with the o-ring on top)
2) clean off the top face of the bottom part of the thermostat housing - scrape with a razor blade and wipe clean with a clean rag - same for bottom face of the top part of the thermostat housing
3) you can put a very thin coat of "The Right Stuff" on those newly cleaned faces before adding the gasket and putting everything back together. But make sure those faces are clean and dry (can be tricky to do with fluid still in the bowl of the bottom part of the housing, but it is an art...not a science)
4) put some Permatex copper anti-sieze on the threads of the bolts before threading them back in.
5) Don't over tighten the bolts. Just Snug. Remember, you are threading into aluminum, which is soft and can easily be stripped.
6) Burp
7) Run and evaluate if further repairs are necessary. If you do decide that you need to install a new water pump, no need to go back and undo the thermostat stuff. Just remember to burp again after that fix, too.

Hope that helps.
 
"Slow Left"

WOW! Thank you SOOO much for that concise and quick write up! It couldn't be any better!

I'm already ONE step ahead of you per your first post: said buddy already inspected the water pump and fan clutch and found them to be in good working order. In other words: he drove it around and got it to driving temperature, checked the weep hole on the WP and found it dry and with the fan offering resistance, he knew the clutch was good too. Only my luck with this vehicle - the next day when driving around town, I returned home and found a little geyser of coolant eminating from the thermostat housing. Bad luck I guess it didn't happen when he drove it???

I will do what you said above and I have a wire wheel set-up in my garage to clean any corroded bolts too before putting everything back together should I be lucky enough not to have any unexpected issues. And oh yes....burping for sure!

Thanks a bunch!
James

...oh ya, new belts are on already after getting the vehicle and I'm getting new hoses for other areas leading to the heater core. I have new ones in place for the radiator and the 2 up on top going into the housing.
 
You bet. Good luck. Sounds like you've thought it pretty well through.

Just a quick point to add onto what I suggested about the new water pump, belts and hoses (and what FJ60 Seth points out as well), is that many of us carry back up things like new water pumps, belts and important hoses anyway in our rigs. Once again, considering that you have recently purchased the rig, it is a wise idea for you to go ahead and install a new water pump, belts and hoses anyway. All those hoses (including the heater hoses) are ~30 years old. When one goes, and you replace it, then the 'weakest link' in the system now becomes another hose that you have not yet replaced. See where I'm going with this?

Do the thermostat job, see how it works, and then develop a strategy for dealing with the other hoses and water pump. Your buddy, no matter how capable and observant, can't predict if the water pump is going to fail. The weep hole will tell you that it is failing. Like I said, most of us carry back up parts, and a water pump is one of those items.

Back up belts are a must, so when you do a job that forces you to remove the belts you currently have installed, replace them with new ones and throw the old belts in the back of your rig for emergency.
 
"Slow Left"
Well as we can say in the fire service; we can train and be prepared, but we never know whats going to be thrown at us.

Good advice and points well taken.

Cheers,
James
 
When removing the bolts from the T'stat housing, patience will help greatly. Chances are good that one or more of the bolts, if never before removed, will break or strip the soft threads in the bottom housing. If you can heat the bolts/housing without damaging anything, then crack the bolts a 1/4 turn and douse liberally with penetrant, over the course of a day, you can reduce the risk of breaking stuff.
 
...and COAT the bolts with anti- seize (the whole bolt) on reassembly. Same with the water pump. It'll help in 5 years...

t
 
Slow Left said:
View attachment 879199

Here, if you've already decided to open the thermostat housing and replace the thermostat in order to: see what is going on in there and check for cracks in the housing...before moving on to other things (like the water pump and hoses and such), then that is fine. Easy enough to do.

Just remove the four bolts on the housing and lift of the top part of the housing. Don't even need to drain the radiator.

Just when you reinstall the new thermostat:
1) make sure it is installed right side up (the picture below shows it installed the correct way - with the o-ring on top)
2) clean off the top face of the bottom part of the thermostat housing - scrape with a razor blade and wipe clean with a clean rag - same for bottom face of the top part of the thermostat housing
3) you can put a very thin coat of "The Right Stuff" on those newly cleaned faces before adding the gasket and putting everything back together. But make sure those faces are clean and dry (can be tricky to do with fluid still in the bowl of the bottom part of the housing, but it is an art...not a science)
4) put some Permatex copper anti-sieze on the threads of the bolts before threading them back in.
5) Don't over tighten the bolts. Just Snug. Remember, you are threading into aluminum, which is soft and can easily be stripped.
6) Burp
7) Run and evaluate if further repairs are necessary. If you do decide that you need to install a new water pump, no need to go back and undo the thermostat stuff. Just remember to burp again after that fix, too.

Hope that helps.
Click to expand...


good pic & tips.....way too many people get that hosed up...

the permatex red fast tack stuff works really well for gasket applications like the thermostat housing gasket..use with the gasket.
 
Don't know if I mentioned this but I Kroil'd and used some cutting oil on the bolts the other day. So when I go to remove them, that should help a bit.

Thanks again for the tips everyone.

James
 
A squirt of Kroil on a 30 year old electro-galvanic corrosion bond won't do s***. Be prepared to either replace or repair the lower thermostat housing unless you're very very careful removing the bolts. You can youtube some techniques.
 
The housing is aluminum the bolts are steel. just take your time, work clean and be sure you orient the parts correctly. Watch out for the old vacuum hose on the smog valves (BVSV's) they will stick and break the nipples off I recommend cutting the hose off with a razor.

Dyno
 
HARRUMPH!!!! @#$%!!!! &%@$!!!!

YEP...just as I feared, after much TLC as I tried when applying pressure - 2 of the 4 bolts sheared and BROKE!!!! And from the looks of the other 2, I'm surprised those didn't break either! And to add insult to injury, the thin little wire on top of the housing simply fell away from its plastic connector!!! I guess rust and corrosion was holding it.

Should I just part this thing out??? I'm afraid what the rest of the engine and wires are like. After all, if I had this much trouble with something simple, have I opened a Pandora's Box here??? I guess the whole engine and suspension should be removed, cleaned, inspected and redone.

I'd post a picture but I'm VERY VERY frustrated!!! Since the year I've had it, its been driven only a little and that's mostly errands around town. :-(

@#$%!!!!!!!!!!!!!!!!

James
 
see if the bolts can be removed and or the threads in the housing helicoiled. Obtain a new lower thermostat housing if required. I agree that it would appear that in general these trucks have far too many bolt failures. But specifically when you have steel bolts and aluminum threaded parts...the result long term is problematic. Depending on the application anit-size on the bolts is very important.

The plastic connectors under the hood will snap very easy and various things are easy to break after 20+ years.

To be fair I had a thermostat housing bolt break off in an aluminium intake on a GM V8 and I'm sure the same thing has happened many times with all brands of engines.

The problem with the LC...is that the vehicle was mfg in very low numbers...and uses many specific parts unique to the LC itself, and therefore parts can be hard to obtain, along with that add the number of years that have passed since the vehicle was new.
 
<< sigh >>

The lower housing can be easily repaired or prolly salvaged. Do you want to know how, or would you prefer to continue on with your tantrum for a bit?
 
I remember on my first FJ60, I drove it over to a buddies house one summer day, just turned onto his street, and the engine just stopped. I pushed in the clutch and coasted over to the side of the street and felt my heart sink into my stomach. Scenarios of seized pistons and the like flashed through my mind. In my panic, I predicted the worst case scenarios possible that my powerful imagination could render and my novice mechanical skills allowed. The rig sat there all summer until I moved into a place with a driveway. Shamefully, I had it towed there.

With no MUD (back in the day), I resorted to two strategies in order to try and figure out what was wrong with it. I would call Toyota dealerships, ask to talk to a mechanic, and then run by my worst case scenarios - hoping to get the guy to talk enough to help me figure out if my theory was correct or not. Also, in auto parts stores, I hoped to run across guys like Spike Strip, Elbert, Toby B, Dynosoar, and FJ60 Seth; guys who could temper my hysteria by them walking through the problem solving out loud so I could see them applying their skill and judgment. It wasn't until, persuaded by a mechanic to try and start it ("...you've gotta try to start it at some point and see if it turns over...so why not now?"), that I turned it over, felt the belt that ran over the air pump (I didn't know it was called an air (aka smog) pump, let alone what it did), that I realized that the pump might have seized, causing friction and making the belt hot. And here I was talking all this nonsense about getting the engine rebuilt...

Your anxiety is caused by fear of the unknown. Uncertainty. Your mind is dragging you into future scenarios that haven't yet happened, and because you are not yet an expert on FJ62s, you can imagine some very disastrous things.

Fear is only helpful (i.e. a useful motivator) in the face of an existential threat (life and death; like being shot at or chased by a saber tooth tiger and so on...). In this case, you are not faced with an existential threat.

The correct way to approach situations like this is through problem solving. By focusing on the process (in other words, the next step you must take in the logical of solving the problem at hand), you achieve two things. First, focusing on the next step you have to take, in other words the details, will bring your mind into the present (and away from the grip of fear of future scenarios). Second, by focusing on the next step you are working towards your goal. Progress!

Embrace the process. Mountain climbers don't climb mountains to remain the rest of their lives on the top of that mountain. It's not possible. Without gravity (I'm using a metaphor here- I think it is a metaphor- for challenges), mountain climbing would be pointless (there would be no opposing force, therefore no challenge to overcome...so no sense of accomplishment).

The equation is this:
Get knocked down 7 times...Get back up 8.

Do this:
1) Post some pictures and a quick write up of what happened (like which bolts broke first, whether or not the top of the housing is off and the two studs still in bottom of the housing are accessible...)
2) come up with a strategy using feedback you get based on the info you provide above
3) fix it
4) evaluate the fix
5) keep learning!
 
Last edited:
HAHA! Thanks for the replies guys! I think I'm through :crybaby: for a while. I'm trying to convince myself it couldn't be helped and the comments above help ease my anxiety. I suppose God Almighty (the REAL one not the Jim Carrey version) couldn't have done better!

I know both bolts need an "easy out". The left rear and the front right. I'm very impressed the other bolts didn't snap too. I mean those things are caked in rust and I think I'd be better off with new or cleaned versions. I'll post a photo or 2 tonight. And what about that wire? I know its hard to know which so I'll take a photo of that too. It broke right where the connector housing is.

YES!!! ANY help would be appreciated!!! ANY recommendations would be accepted!!! ANY offer of parts to sell would be considered!!!

I'll change the name of this truck to "FLOWER"....because like a flower....its something pretty to look at but don't DARE touch it or the petals will fall off. Just keep watering ($$$) and it will survive!!!!

James
 
With auto mechanics, the math is brutally void of human emotion. In other words, when looking at a part or a component, you have total control over it and the outcome of the process.

If...then...

If I do this, then this will happen.

Sometimes factors, such as rusty bolts, throw uncertainty into your evaluation of what is going on. That is where skill and judgment, learned over time, come in.

Just know that you can fix anything, it is just a matter of resources (knowledge, time, and money) and persistence.
 
This thread might belong in the new "psychotherapy" section of the forum instead of "tech" :D But I'm enjoying it and reminiscing about my first cruiser. Good times......good times.
 
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