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View Full Version : do I need a new thermostat?


nakman
09-17-2006, 10:31 AM
Yesterday while wheeling up Jenny Creek the heat in the 40 was crankin- so nice and hot. But then we stopped to air up down towards Rollinsville, and after that all the way home the dash only blew cold/slightly warm air. The two hoses that go to the back heater continued to be super hot all the way home.

So did something come loose & plug up the hoses that feed the dash heater? New thermostat? They're easy enough to replace, I guess. any other thoughts? :bowdown:

edit: oh, and the temp guage on the dash never moved, stayed about a needle's width below the first line... 32 on a scale of 1 to 100.

Romer
09-17-2006, 10:42 AM
I have a thermostat for the 40, you can have it. It was one of those misc parts I asked if you wanted or I should sell. Like the Hoses, Head Gasket, etc.

It's yours though. They are not to expensive.

Uncle Ben
09-17-2006, 11:09 AM
I have a thermostat for the 40, you can have it. It was one of those misc parts I asked if you wanted or I should sell. Like the Hoses, Head Gasket, etc.

It's yours though. They are not to expensive.

Sounds like the thermo is doing it's job. Sounds more like a door/baffle on the heater itslf or maybe the hot water control valve?

nakman
09-17-2006, 12:28 PM
cool, thanks Ken I will take that thermostat.. just to rule that out.

Sounds more like a door/baffle on the heater itslf or maybe the hot water control valve?
Ok, that makes sense. So should I just take this doohickey off and see how it looks? I could also stick a straight pipe in there, then I should have all heat all the time, right?

Romer
09-17-2006, 12:42 PM
Did you flip on of the levers on the heater? I think one does defrost and There is a knob to get freshh air, if I recall. If you pulled this while trying to get the frost going, that might explain.

It might be worth it to take that owners manual out of the glove box. Also might want to make sure the door flap to the blower is opening an closing to the outside. To see, you remove the duct on the passenger side between the heater and firewall. You should be able to pull the know and see the flap open and close to allow the heater air or the fresh air. You probably just had this off when you changed Radio's

I'm may be wrong as my 40 knowledge is dis-apperaing while I like for a Esppresso machine for the Lexus.

subzali
09-17-2006, 03:54 PM
Thanks for the pic Nakman, that's what mine's supposed to look like and doesn't! If you straight pipe it you will get heat all the time as I do, so I tell ya what I'll switch ya for what you got and we'll go from there! ;) No seriously I kinda ran into the same problem on the TBP and don't really know what's going on. It was hot for a while and then cool. My only thought is the air temp. that it's pulling in...maybe if you put it on recirculate (push in the "fresh air" knob on the dash, you'll hear the door slap closed) it'll suck in warmer air and be hotter? Similar to going slow on the trail where it doesn't have to fight convective heat loss from the air blowing by? I dunno :confused:

You might have some kind of junk/constriction at your valve inside the engine too, which could have gotten jammed in there while the heater was on and is preventing hot water from flowing into the cab. Do your hoses to the front heater have insulation on them? Can you feel if they're nice and hot all the time like the rears?

Also, is your fan staying on, or did it go off and make it feel like the heater wasn't outputting as much heat? Mine's being kinda finicky right now and doing just that.

nakman
09-17-2006, 03:59 PM
My fan will stay on, but blows cold air. The "warm" knob only has about 1/2" of travel to it, so I'm thinking that cable linkage may be in need of some adjusting. I got the same results with "fresh" in and out. Yes, I read the manual.. :rolleyes: I'm going to mess with it some more after the game.

subzali
09-17-2006, 05:06 PM
my fresh knob has about 1/2" as well, I think it's a stop that's built into the knob itself, not the linkage. sounds like your thermo is working though, if the engine wasn't changing temps along with your heater.

Romer
09-17-2006, 06:43 PM
Did you take the duct off? Maybe the cable got kinked when you did your radio

nuclearlemon
09-17-2006, 10:26 PM
air bubble in the coolant maybe?

nakman
09-17-2006, 10:35 PM
I think this all operator error. I thought that "vent" would imply hot air blowing at you in the face. Instead it's just outside air, regardless of where the "fresh" knob is pulled to. So if I pull that flippy thing behind the shifter towards me, I get hot defrost and hot air blowing towards my feet (and a hot rear heater.) If I push it forward then I get cool air blowing at my face (regardless of "warm" knob setting), and a hot rear heater. I pull the "fan" knob once for a low fan up front, and all the way out for fan on high, and the rear fan- all that seems to be working great. So there's only two settings for the flippy thing on the side of the plasic duct, right?

Not used to these here climate controls... I need my buttons! :o

subzali
09-18-2006, 12:29 AM
Flippy thing on the side of the plastic duct? :confused:

The lever on the left side of the heater should have three positions - one for heat/defrost, one for heat only, and then you flip it and it blocks off the heater core and directs the air to vent. The "fresh pull" knob on the dash only has two positions - fresh and "recirc" (at least as much as you can recirculate the air inside a 40 :lmao:)

levers, knobs and clutch feathering - the wave of the future! ;)

BTW Tim did you get your clutch fixed yet?

nakman
09-18-2006, 09:53 AM
Ok, I think that thing is broken then, because I can only get 2 positions.. I need to look at another 40 to see what's different, then I'm sure I'll be able to fix it once I know what I'm fixing. thanks for the tips, all!

BTW Tim did you get your clutch fixed yet?
Yes, that my first deRomering. I bought a new master & slave from MAF, made a world of difference!

Romer
09-18-2006, 10:37 AM
It had only two positions when I owned it.

deRomering . . . . careful you might find yourself lost in the Ozarks squealing like a pig.:eek:

Hulk
09-18-2006, 12:31 PM
Different years have different controls. I don't think the earlier years had defrosters, did they?

Rzeppa
09-20-2006, 07:36 PM
On the 77 there are three positions. Vent is outside air diverted toward your face before it goes through the heater core. This is to compensate for the removal of the cowl vent in 1974. Middle position puts most of the warmed air to your feet, and a little to the windshield. Position farthest back toward the operator is defrost only.

Prior to 1974 model year (7309), the front heater did not have the "vent" option because the cowl vent was still existing. Unlike the later front heaters, the early ones have an infinite adjustment of how much hot air is going to your feet or the windshield, completely mechanical analog control. After that it's either feet or windshield, although when you take the box apart you can see that some goes to the windshield even when it's in the feet postion.

Unlike most things Toyota did through the years, I think the later 40 front heater was a step backward in functionality and usefulness from the earlier arrangement. I'd love to retrofit an early style cowl vent to my 76. I can't (easily) on my 78, because the even the vestiges disappeared starting with that model year.

Rzeppa
09-20-2006, 07:41 PM
Different years have different controls. I don't think the earlier years had defrosters, did they?AFAIK, defrosters were introduced at the same time as heaters with the 1958 model year FJ25 in some markets. From the photos I've seen of the 1957 FJ25s, which were originally sold in Oz, those didn't have heaters at all. As late as 1982 some markets still didn't get heaters, although dealers sometimes retrofitted them, as they did with locking front hubs on USA models from 1963-1978.

nakman
09-20-2006, 07:51 PM
Wow, this proved to be most informative.. thanks! :beer2:

Uncle Ben
09-20-2006, 08:07 PM
AFAIK, defrosters were introduced at the same time as heaters with the 1958 model year FJ25 in some markets. From the photos I've seen of the 1957 FJ25s, which were originally sold in Oz, those didn't have heaters at all. As late as 1982 some markets still didn't get heaters, although dealers sometimes retrofitted them, as they did with locking front hubs on USA models from 1963-1978.


My 64 had no heater originally.....the sad excuse for a black box it has now would still clasify it as no heater. :rolleyes:

Rzeppa
09-20-2006, 08:15 PM
My 64 had no heater originally.....the sad excuse for a black box it has now would still clasify it as no heater. :rolleyes:Curious, does it have the ports on the underside of the cowl for defrost?

With the advent of cooler weather in the USA, this topic has come up on the LCML recently.

Uncle Ben
09-20-2006, 08:17 PM
Curious, does it have the ports on the underside of the cowl for defrost?

With the advent of cooler weather in the USA, this topic has come up on the LCML recently.

It does now but no, it didn't. Original windshield had the screw vent but no ducts and the cowl was solid as was the rubber weatherstrip.

Rzeppa
09-20-2006, 08:21 PM
kewl. Another snippit of knowledge to add to the collective.

corsair23
09-20-2006, 10:47 PM
Different years have different controls. I don't think the earlier years had defrosters, did they?

My '76 had a defrost position and it worked just fine (after Ron at RMC rounded me up some tubes and put them in it did any anyway :) ). My '74 has an aftermarket Mojave heater and I don't think it has anything other than on and off, straight out heat. Not sure this helped but :confused:

wesintl
09-20-2006, 11:41 PM
It does now but no, it didn't. Original windshield had the screw vent but no ducts and the cowl was solid as was the rubber weatherstrip.

huh. I have ducts in mine. Did they add those as dealer install when they put in heaters? I always thought they were there and if you wanted a heater they just hooked up the hose....

Uncle Ben
09-20-2006, 11:47 PM
huh. I have ducts in mine. Did they add those as dealer install when they put in heaters? I always thought they were there and if you wanted a heater they just hooked up the hose....
No idea! I know my 64 was as basic as they come. Convertible, no heater, only accessory was the wipers. BTW....Mine is titled a 65 but brass tagged 64