THERMOSTAT REPLACEMENT 101 Tech PicTutorial

Today I went out and replaced the thermostat in my 91 F350 AKA White Rhino!

As per the many members of Oil Burners forum have discovered

FORD Motorcraft or actual International thermostats are what you should use. DO NOT USE AFTERMARKET thermostats. If you do, do so at your own risk. This install is showing Motorcraft parts and part #'s in Canada!

Here is the basic thermostat replacement method I used, feel free to use what you like.

DOING THE PROCEDURES HERE ARE DONE AT YOUR OWN RISK, I DO NOT TAKE RESPONSIBILITY FOR YOUR CHOICE TO DO WHAT I HAVE DONE. THIS WORKS FOR ME, IT HOWEVER MAY NOT WORK FOR YOU.

AL

I don't provide a tool list because if you don't have the tools to do this job, you likely shouldn't be doing it.

MAKE SURE BOTH BATTERY GROUNDS ARE DISCONNECTED PRIOR TO ANY OF THIS, NOT DOING SO COULD BE CATASTROPHIC!!!

Also NEVER place tools, wrenches, extensions, ratchets etc on battery doing so could be explosive due to a direct short between posts!

icanfixall said:

.... a reason for removing the battery cables.... For those that don't know... That heavy line going to the alternator BLACK and YELLOW Stripe is always HOT. That's about 2000 amps ready to burn off the tiny wire if it accidentally touches a ground.

If you think you can keep it from grounding then give it a try... But experiences have taught many differantly.

The amps will smoke the wire faster than a prom dress comes off in the back seat of a 55 chevy...

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Here we see the engine prior to me doing anything to remove the thermostat, notice the rag in the upper rad hose fitting to keep debris out!




Remove Alternator from it's location and set aside


Remove the Vacuum pump, and now is a great time to service it with fresh oil too BTW, set aside



Remove the 3 bolts holding the vacuum pump mounting boss in place, this also releases the fuel filter mount so be careful of it moving


LOOSEN/ no need to remove this bolt I am pointing at, I forgot to take this pic when doing tear down, hence the clean water neck


Carefully move the fuel filter mounting bracket back just enough to access the bolts in the thermostat housing


Undo the two thermostat bolts


Remove the thermostat housing, then you should see something like this here. Gasket looks ok except on lower LEFT corner by lower bolt


Back side of thermostat housing, check for the little ball...it's there...Good! surface again not too bad..just lil clean up needed

icanfixall said:

About the ball. The design is to allow trapped air to purge out of the cooling system back into the radiator. then when the coolant touches the ball it pushes the ball up to close off this pathway. Most times if you squeeze the top hose from the thermostat housing you can hear the ball clicking in the housing if its there and its not gumed up with corrosion....

Click to expand...

These next two shots show the cleaned up gasket surface on the block, I'm usually a stickler for super super clean...SURGICALLY clean actually, but today I was lax...it was raining and cold...still it's good enough for what we need to accomplish here today!




Ya, these need a thorough engagement with a wire brush...


These two pics are the NEW MOTORCRAFT thermostat box..thermostat was in the box...lol... THIS WAS SHOT FOR THE #'s



The NEW Thermostat, even has markings TOWARD RAD and arrow point up...SAWEET



That's it so far, MORE TO COME

Al

Continuing on from where we left off moments ago,

Here the test fit of new thermostat in the block, looks good. I noticed that this tstat had no gasket on the outer edge like some I've seen


My ever present bottles of stuff...Left to Right...ELEPHANT Snot, Anti Seize, Thread Sealant, the latter has another nick name, I WON"T TELL! I can see that by the amount of anti seize I have used, the next bottle is the Large bottle...hmmm....GOOD STUFF!


Here I've applied a light coat of elephant snot to the block, notice I removed the tstat prior to application!


Now the Thermostat is in


Gasket placed in location and lightly pressed down


Freshly painted, and cured for 20 minutes in the oven at 225 degrees. Prior to paint I thoroughly cleaned the housing and gasket surface of it, I also dressed the gasket surface lightly with a file to ensure that there where no burrs or other problems that would crop up when assembling or after assembly


Gasket surface dressed and ready for some elephant snot, sorry about the glare the flash went off...You get the idea though

icanfixall said:

Good clear pics showing the bleeder BB very well. See that square thing in the housing.. you always want to see that in place holding the BB in there..

Click to expand...

Surface of tstat housing with some elephant snot, now I'm ready to start assembly!

icanfixall said:

About the ball. The design is to allow trapped air to purge out of the cooling system back into the radiator. then when the coolant touches the ball it pushes the ball up to close off this pathway. Most times if you squeeze the top hose from the thermostat housing you can hear the ball clicking in the housing if its there and its not gumed up with corrosion....

Click to expand...

Thread sealant applied to the thermostat housing mounting bolts.


Here a nice shot of housing installed and snugged down, I used my highly calibrated fine tuned hands on a 3/8 drive ratchet and say 12-14 Ft lbs is what those are....honestly though, I do not know and don't care, I am happy with MY SNUG and my level of torque...


Now it's time to line up and install the vacuum pump mount bracket, notice the anti seize on these bolts, just install loose for now...


Now that the lower bracket bolts are in and snugged, not tight, Tighten this bolt, then go back and tighten the three bolts holding the vacuum pump boss in place which secures the fuel filter mount too. Once the bracket is tight just install vacuum pump, I wasn't bothering with that picture!


While I was doing the Thermostat, I wanted to change out the alternator as I was having some small charging issues, this also gave me an opportunity to put the spare in with a better location on the wiring. You'll notice this Alternator is clocked 90 degrees counter clockwise from front...as to the old one in the first portion of the thread.


Here it's all back together, awaiting a NEW Champion RAD, I have new hoses all ready to go!



That's it for now...hope it helps some people out and you enjoyed the pictutorial

Thanks for reading, if you have any questions or suggestions, feel free to fire away.



Al

Good clear pics showing whats what on this job. The bleeder BB is shown very well. See that square thing in the housing.. you always want to see that in place holding the BB in there. About the thermostats you picutred. I cut off the top area of the rubber gasket so I get more flow around the body of the stat. You also got a clear picture of the bypass hole below the thremostat in the block. Nice pic. Now if you had a radiater installed I would recommend testing the thermostat gasket before you installed all the parts to the front of the engine. Any leak at the housing gasket will cause the complete redo of the job. Still I like what your doing. This will help those to be able to actually see what this simple job takes. Might give a reason for removing the battry cables. For those that don't know... That heavey line going to the alteranter is always hot. Thats about 2000 amps ready to burn off the tiny wire if it accidently touches a ground. If you think you can keep it from grounding then give it a try... But experiance has taught me differantly. The amps will smoke the wire faster than a prom dress comes off in the back seat of a 55 chevy...

The amps will smoke the wire faster than a prom dress comes off in the back seat of a 55 chevy... Gary now thats funny an yet very true.
Nice write up Al thanks for the pics.

icanfixall said:

.... a reason for removing the battery cables.... For those that don't know... That heavy line going to the alternator BLACK and YELLOW Stripe is always HOT. That's about 2000 amps ready to burn off the tiny wire if it accidentally touches a ground.

If you think you can keep it from grounding then give it a try... But experiences have taught many differantly.

The amps will smoke the wire faster than a prom dress comes off in the back seat of a 55 chevy...

Click to expand...

Noted and deal with Gary, good point thanks!

great write up! thanks

Well, I see only one clean part under that hood

I think Gunk engine cleaner and a pressure washer is long overdue

nice work Al. Gary, that is sig worthy material right there.

Good write-up, Al. Nice, step by step instructions, with clear explanations of why things must be done.


BTW, what is the vernacular name for the thread sealant? It sounds like one of those Canadian only things, eh?;p

So... I just noticed something differant about the belt running the vacuum pump. Its not running off the alternater. Its running off the water pump pulley. How it that done. Is the ac compressure not being used on this engine... I kinda like that idea because it takes the belt load off the alternater bearings.....

icanfixall said:

So... I just noticed something differant about the belt running the vacuum pump. Its not running off the alternater. Its running off the water pump pulley. How it that done. Is the ac compressure not being used on this engine... I kinda like that idea because it takes the belt load off the alternater bearings.....

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NOPE...NO AC.. truck never came with AC....dual pulley on PS pump and ALT, triples on crank and on the WP....works well...

Can't wait to dump the V belts and get me a real SERP setup...hate V belts, just need a NEW tensioner and Idler pully and I can install serp setup once and for all!

Check ebay for the idler and tensioner. The open spring tensioners are around $50.00 and the shock absorber type are just a bit more. I can post what you need if thats something you want to actually see on ebay. Sometimes they are not pictured correctly either...

icanfixall said:

Check ebay for the idler and tensioner. The open spring tensioners are around $50.00 and the shock absorber type are just a bit more. I can post what you need if thats something you want to actually see on ebay. Sometimes they are not pictured correctly either...

Click to expand...

YuuuuuuP.....Please do Gary, it may be a bit before I afford one but please post them...I just blew a little bit of cash on truck and wife may wonder why more....cause I gots to get my 3G alternator on hon...that's why

Holy shnikees, 2000 amps? Isn't 75 ma the fatal level?......i always disconne,t my batteries but I never knew there was that kinda current running......so would.a.3 g alternator.have 3 k amps then?

gdhillon said:

Holy shnikees, 2000 amps? Isn't 75 ma the fatal level?......i always disconne,t my batteries but I never knew there was that kinda current running......so would.a.3 g alternator.have 3 k amps then?

Click to expand...

The HOT lead on the ALT is wired directly to + on solenoid and direct to battery from there...short that out....big time mess...wires get hot..burning acrid smoke...grabing wires on fire...don't freakin ask....ya it's bad...

NOPE 3 G = Third Generation alternator is all.

Likely 130 Amp output ...Mine...250 Amp output...that's why I want it...

That V belt Alt is lucky when warm to put out 85 amps I'm guessing...rofl