Pictures, notes, problems, and solutions when changing the thermostat housing

[Team Chepsk8]

As most of you read in my venting post, replacing the thermostat assembly was not the delightfull and easy job we are hoping for. Dis-assembly was a motherF%$$#^ and the true culprit of all the problems was found, a $3.00 "O-ring".

I went on-line, and found at a few locations a replacement assembly, a DORMAN 902-204. I also ordered a new lower bypass hose, since I had cut up the old one, and while it was that far apart, best bet was to replace anyway. Advance Autoparts had one in the next morning, so I ordered there, $149.00.

I went to the store with the old parts to compare, and it was good I did. The party physically had the same body dimensions and mounting holes, but the part came without sensors, and the replacement part had different sized threaded holes, much different than the Ford part:

 

[Team Chepsk8]

So, realizing I was between a rock and a hard place, I checked with the parts guy there to see if they had the two sensors in stock that fit the new housing. Thankfully, they had both! Parts are: Made by BWD, P/N's WT724 & WT5053. I added them to the growing parts pile, and hoped they would work.

Installing the new housing was much easier with the alternator and bracket gone:

A second issue the immediately became apparent with the thermostat cover/outlet. The outlet had a higher angle than the original piece, and hit the throttle body mount on the intake manifiold. As well, the new one has metal inserts in its flanges, where the old one mounted over the extended metal inserts.

I opted to modify the original outlet, so using various sockets and a bench vice, pressed the inserts out of the new part

And then enlarged the holes in the original part and pressed in the inserts with the vice

From there, reassembly finished normally with no other hiccups. I forst filled the system with water, so when testing and if it failed, just water was wasted, not expensive anti-freeze. Got it running and let the truck run for a while, building heat, and checking the temp gauge, which read identical to how it did with the Ford sending unit.

Drove it around doing errands, and so far no leaks or smoke. I will watch it carefully for a few days to make sure it's fixed before taking any long trips.

Hope all this info can help others out there who are contemplating this repair. It's a Major PIA, but can be done, and you will save yourself a huge amount of $$$$.

Dan

 

[Team Chepsk8]

And some final notes, here is the real problem encountered when dis-assembling:

When the O-ring failed, it allowed coolant to get into the bolt area, and froze the bolt to the plastic housing, so it would not turn and ultimately rounded the head while trying every wrench I had. I ultimately used a Dremel and ground the head completely off and bent the housing and bolt towards the front to remove. A new bolt was purchased at Ford for $2.07 I also used anti-Sieze on all the bolts going into aluminum, so they also would not sieze.

You can also see my cheap repair for the collapsing vacuum hose that also commonly failes, a brass plumbing elbow that fits inside the vacuum hose. Simple, effective, and does not require any hose bending.

My truck just passed the 150,000 mile mark and runs great, so I am hoping this will keep it running a while longer, I do like the truck immensly.

Great web community here, glad to be a part of it!

Dan

 

[Marcq]

Thanks for taking the time to do this

Marc..

 

[ncranchero]

What a PITA to do all that modification to new parts! I'd say they ordered you the wrong housing, there are several.

Thanks for the photos and write-up !

 

[Team Chepsk8]

NCR -

I could not find any other assembly listing, and this was available quickly, so I took it. If there is another Dorman Number, add it to this thread, and then maybe add it to the FAQ's or Tech articles?

Everything is working fine, so I am not complaining, and very happy to identify and show a common problem, and straight-forwards solution.

Dan

 

[blackbeauty]

Does anyone know the route of that vacume house he has taped up? The one next to the --stat housing. mines all chewed up and looks like a pita to replace. thanks

 

[just1me]

And some final notes, here is the real problem encountered when dis-assembling:

When the O-ring failed, it allowed coolant to get into the bolt area, and froze the bolt to the plastic housing, so it would not turn and ultimately rounded the head while trying every wrench I had. I ultimately used a Dremel and ground the head completely off and bent the housing and bolt towards the front to remove. A new bolt was purchased at Ford for $2.07 I also used anti-Sieze on all the bolts going into aluminum, so they also would not sieze.

You can also see my cheap repair for the collapsing vacuum hose that also commonly failes, a brass plumbing elbow that fits inside the vacuum hose. Simple, effective, and does not require any hose bending.

My truck just passed the 150,000 mile mark and runs great, so I am hoping this will keep it running a while longer, I do like the truck immensly.

Great web community here, glad to be a part of it!

Dan

Do you know the part number for that bolt? I got a new housing but yet to swap it out, tried it once but stopped cause 1 stubborn bolt wouldn't budge the very back one, so I would rather be prepared 2nd time around.

 

[just1me]

Nevermind I finally found it, Ford part #W702527-S437

 

[swshawaii]

Do you know the part number for that bolt? I got a new housing but yet to swap it out, tried it once but stopped cause 1 stubborn bolt wouldn't budge the very back one, so I would rather be prepared 2nd time around.

http://bengrosser.com/howto/fordthermostat/#partslist

http://bengrosser.com/howto/fordthermostat/

 

[just1me]

Thanks I should have noticed that, I guess my brain is to tired from working on this thing.

 

[zukgod]

If you only needed to replace the thermostat, would you go ahead and replace the thermostat housing? My truck is a Job 1 so it's bit different than yours. But it looks like such a pita job is it worth the extra cost? Or are the housings failing not common. Also that little stubby hose under the thermostat housing looks like a pain to replace without taking the housing off. Thanks for any guidance.

 

[just1me]

Only if the housing is leaking at the base or at the seam would I replace the housing. It is kind of a pain removing the housing, for some it seems to go smoothly, but for others not so. The thermostat itself though is simple to change, it can be done in less than half an hour.

Here is a Job 1 thermostat change.

http://www.explorerforum.com/forums/showthread.php?t=304706

 

[zukgod]

[MENTION=54513]justme[/MENTION]
Thank you for the advice and the link. I just noticed that my temp is fluctuating an awful lot and my truck is not running at the same temp it once did. So I am assuming that my T-stat is stuck open. Gotta do my spark plugs tomorrow also, those look horrible to do.

 

[just1me]

Yeah a thermostat stuck open or stuck closed can do that. For the spark plugs you can remove each front wheel and remove the small splash shields that are held on by push pins. Myself I have yet to do this job, although I already got the new plugs and wires, I will probably remove both inner fenders just for the extra clearance.

 

[zukgod]

That's what I was thinking of doing as well. I think it's about time 150k on the stock plugs and wires is a bit to much lol. Hope it helps with my idling issue, my poor truck is in dire need of some work. Still runs like a top and looks new though.
Thanks for your help buddy.