Has anyone had a problem with breaking the bolts off when changing the thermostat? I need to change mine, but its never been changed and I have around 212,000 miles.

 

Heat the bolts up with a propane torch, and tap on them lightly with a hammer to loosen any rust-bond they may have. After they cool down you should be able to remove them without breaking.

 

Also be sure to spray penetrating oil in there. I used PB Blaster, it works great. Try soaking them a day or days in advance too. Once you get it off, spend as much time as you need scraping the old gasket away to make sure you get it all off. Good luck.

 

As far as those old bolts go, use penetrating oil on them and go easy. If the truck has 200,000+ miles on it, and those bolts are stuck on there like that, you might be looking at a water outlet that has never been removed from the head.

If the thermostat is original, and based on the year of the vehicle in question, you are not going to be able to find an exact match for the thermostat. The original thermostat should have two thin metal flanges, that look like wings, on the radiator side of the thermostat. These flanges allow the thermostat to be "locked" into a recess on the water outlet, and hold the thermostat in place while you are remounting the water outlet to the cylinder head. This, in turn, allows for a true mounting of the water outlet to the motor which prevents coolant leaks.

New thermostats don't have those flanges on them. Why? I don't know.

Make sure, as suggested above, that you clean both mounting surfaces very well. Mount the gasket to the head, not the housing. Take some RTV sealant and apply a thin bead onto the recess of the water outlet, in which the thermostat sits. After about a minute, set the thermostat into this recess and make sure that the RTV is holding the thermostat in place. This will keep it steady and centered while you mount the water outlet.

I hope this helps.

Garry Baker

 

It's cheaper to make them without the flanges.

JEFXXO: Make sure when you remove the t/stat you notice which way the element is pointing (towards the engine). Some ppl forget, or don't notice and install the new t/stat backwards, causing the engine to run very hot.

 

Thank you all, it went flawless. they unscrewed like they were lose. Used the Blue gasket maker and it set it in place. Went together without a hitch. no leaks, and it seems to be heating like normal again. Just in time for winter. For reference, it makes it alot easier to remove the Belt to get to the bottom right bolt of the thermostat. Oh and keep a catch pan under your truck to catch the green slime. Thanks all

 

I am glad it went well.

As far as placing a drain pan under the truck to catch "green slime" goes...

You should attach a section of 3/8" tubing to the drain-**** of the radiator and drain the fluid out of it. Actually, you should drain it dry. This will accomplish two things:

1. It will drain the cooling system of fluid, which will help you to keep your cylinder head and engine block dry. If you just pull the thermostat housing (a.k.a. water outlet) off before draining a sufficient amount of coolant from the water jacket you will just wind up with a big mess all over the place. Keep it clean.

2. Anytime you are replaing the water pump or thermostat is a fine time to replace coolant. It's just good practice.

It's also a great time to flush the radiator.

Garry Baker