http://forum.ih8mud.com/attachment.php?attachmentid=1312&stc=1

So, why did someone put this threaded cap into my thermostat housing exit hole, and is it good? Should I keep it that way? Or drill it out more?

what the hole used for, either I am still asleep or I have never seen a hole in that place before.....wierd

http://forum.ih8mud.com/attachment.php?attachmentid=1312&stc=1

So, why did someone put this threaded cap into my thermostat housing exit hole, and is it good? Should I keep it that way? Or drill it out more?

When the thermostat is closed (cool) the coolant is directed back from the top of the engine to the water pump via that port. It then misses the radiator.

Stock hole, it should have a pipe in it that goes back to the water pump. Can't guess why he tapped it and plugged it...

As everyone has pointed out, it is stock, and there is a short elbow hose that goes to the waterpump to circulate coolant when the thermostat is closed...

So, no reason for it to be there. I'll drill it out to original diameter. Just can't think of why they did that. Thanks for the input. If anyone else has a clue as to why it was done, feel free to share. :D

I've thought of using the bypass line as the hot water source for the shower heat exchanger. I don't get enough heat out of my system by tapping into the rear heater line. The bypass line should provide more heat to the exchanger at idle speed. It would be easier to route the lines if the end were tapped for pipe fittings like he has done.

Only thing I can think of.

Good Idea!! :D

. Maybe PO did that to get engine to cool. who cares fix it .

In some of the non-US markets that did not even bother to install heaters in the trucks, they offered t-stat housings AND WATER PUMPS that did not have provisions to be hooked together. I actually have a brand new water pump in the box for the 68-74 non-heater model with no t-stat pipe. It's been sitting on the shelf for 14 years now! Not exactly a big seller. Hth.

P.S. Nice to see you on Pirate, Dave! :D

so if one were to have a truck without a heater :)
would you recommend running a line from the back of the head to the lower hose or just not run said hose? Just curious if it'd be a bad thing to remove the worthless hose in my engine compartment.

Hey, Mark. Thanks for the welcome. This is where the FJ45 folks hang out the most, so I guess that's why I'm here.

That's interesting that they would make a therm housing without the return to the water pump. I guess the return is there to circulate water from the top of the water jacket, and you would want water to circulate if you have a heater. So, if you don't have a heater, the water just sits in the block and doesn't cycle until the thermostat opens on those rigs?

Tornadoalley: you can close the spigot on the heater fitting off the head to prevent hot water circulating through the heaters in the summer. If you don't have heaters, I'd definitely cap that off and get rid of the extra hose.

I'm wondering if maybe the PO used that port to install a sender for an aftermarket temp gauge?

whats wierd is my 45LV has no heater but has the line from the lower hose to the back of the head....just like it would be if it had a heater, no clue why its there.

(crap, Eric.......still want those shocks?)

so if one were to have a truck without a heater :)
would you recommend running a line from the back of the head to the lower hose or just not run said hose? Just curious if it'd be a bad thing to remove the worthless hose in my engine compartment.

Pimp.. Exactly same setup on my truck.. Hose running a nice loop in the engine bay but no heater at all.. Just wondering if we need to get the heated fluid out of the back of the head or if that'd be a problem.

And yes.. I'd like those shocks when you get around to it.. No worries/no hurries been dealing with a totalled honda on my end and a kid that hit me without insurance.. Been driving the FJ62 to work tho! :) 35mtr's are not rush hour friendly! But merging is much easier with the big boat rule!
Thanks everyone for the tech! Weird we need some south america old crusier knowhow to figure out the "no heater" models huh!
Erik..

I've got an even more interesting t-stat to show you guys when I get back to the shop tomorrow. Came off an F135 equipped early firetruck. Had a thermal switch mounted to the upper housing to help regulate vacuum advance on the early fire trucks. Never seen another one like it!