Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

Thermostat Gasket?

Thread Tools
 
Search this Thread
 
Old Dec 16, 2004 | 11:46 PM
  #1  
1996F250PSDLB's Avatar
1996F250PSDLB
Thread Starter
|
New User
Joined: Oct 2004
Posts: 17
Likes: 0
Thermostat Gasket?

I replaced my own thermostat this weekend, however the part I purchased only came with a small thin rubber gasket that fit around the thermostat, and the entire unit dropped into the thermostat housing. Put a little goop in for safe measure, and bolted it down.

Well, a few miles later, the gasket blew out - together with the entire contents of my radiator. Did fine driving down the freeway with no water (Stayed at the "L" of Normal), but once I pulled off the freeway, got the "overheat" light.

So....what am I missing here? Is there a gasket my friendly parts store failed to provide me, or is there an art to the thermostat?

Thanks.
 
Reply
Old Dec 16, 2004 | 11:52 PM
  #2  
farmb0y's Avatar
farmb0y
Posting Guru
Joined: Feb 2004
Posts: 2,365
Likes: 0
From: IOWA
Club FTE Silver Member

I dont' know if they are different on trucks older than '99, but I just flushed my coolant so had my thermostat apart, and it's just a rubber 'o-ring' gasket, sits on top of the thermostat, a couple bucks for a new one from O'Rielly's. You might of not had it in there correctly, that would be my guess anyway. I was worried about it popping out when I put it back together, but it hasn't been leaking. That's all there is to it anyway, just the one gasket. I'd go buy another new one and try again. My .02 cents.
 
Reply
Old Dec 17, 2004 | 07:14 AM
  #3  
mueckster's Avatar
mueckster
Lead Driver
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
Sounds like it was the wrong gasket. It should be a square-cut O-ring that sits on top of the thermostat, not around it. The recess in the waterpump should keep it in place. Check to see if the bottom of the water neck is flat. You may need to straighten it, if it is warped. Put a little bead of RTV (silicone) on the water neck and bolt it down. Give the RTV a little time to "set up" before driving. This is how I did mine, with no leaks.
 
Reply
Old Dec 17, 2004 | 07:38 AM
  #4  
Jeff396's Avatar
Jeff396
Mountain Pass
Joined: Jul 2003
Posts: 199
Likes: 1
From: Fort Mill, SC
Also be sure you have the right thermostat. Did you compare the new one to the old one? From what I understand the auto parts will sell you the wrong part. The one you need is longer than a typical thermostat. If you have a shorter one the coolant flow will be wrong and cause incorrect cooling flow.

Jeff
 
Reply
Old Dec 17, 2004 | 07:47 AM
  #5  
mueckster's Avatar
mueckster
Lead Driver
20 Year Member
Photogenic
Photoriffic
Shutterbug
Joined: Jun 2003
Posts: 8,298
Likes: 25
From: Damon (South East Texas)
Jeff brought up a good point. The thermostat should have the stem on the bottom that closes a bypass hole when the thermostat opens to allow full flow to the radiator.
 
Reply
Old Dec 17, 2004 | 07:50 AM
  #6  
Kwikkordead's Avatar
Kwikkordead
Fleet Owner
Shutterbug
Liked
Loved
Community Favorite
Joined: Jun 2004
Posts: 25,090
Likes: 1,112
From: Rio Rico, AZ.
Also part of the problem is the use of too much "goop". O-rings do a fabulous job of sealing things up all on thier own. All you want to do is to slightly wet the contact surfaces with no extra blobs anywhere. See, the extra goop will get trapped in the groove and when you tighten it down it creates extreme hydraulic pressure in the o-ring channel because liquid is not compressable. It will simply shred the rubber of the o-ring and then you effectively have no gasket.
 
Reply
Old Dec 17, 2004 | 08:50 AM
  #7  
1996F250PSDLB's Avatar
1996F250PSDLB
Thread Starter
|
New User
Joined: Oct 2004
Posts: 17
Likes: 0
Thanks for all the great posts. The truck had NO thermostat to begin with (it used to be run in Calexico, California. Average temp is 80 degrees, so I guess they didn't need it. Also likely why they by-passed the A/C clutch and left it in the "on" position 24/7)

The only gasket I got, was an o-ring, that went around the thermostat. It fit perfectly into the water neck, and I had placed only a thin coat of goop.

Anyway, I drove straight to my trusted mechanic, who will be doing it the right way, including a new Thermostat, for $60.00

My in-laws have a saving, "Cheap usually ends up being expensive". I should have let the mechanic change the thermostat.
 
Reply
Old Dec 17, 2004 | 10:11 PM
  #8  
Kwikkordead's Avatar
Kwikkordead
Fleet Owner
Shutterbug
Liked
Loved
Community Favorite
Joined: Jun 2004
Posts: 25,090
Likes: 1,112
From: Rio Rico, AZ.
Originally Posted by 1996F250PSDLB
Anyway, I drove straight to my trusted mechanic, who will be doing it the right way, including a new Thermostat, for $60.00

My in-laws have a saving, "Cheap usually ends up being expensive". I should have let the mechanic change the thermostat.
Hahahaha. (Good natured laugh here)
I am a mechanic by trade and have fixed few "repairs" too. Thanks for the chuckle. And I don't charge a ripoff price either.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-1

Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-2

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-3

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-4

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-5

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-6

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-7

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-8

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-9

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rascal1
1999 - 2003 7.3L Power Stroke Diesel
11
Aug 22, 2014 05:56 PM
Jeffbilyeu
1978 - 1996 Big Bronco
2
Apr 22, 2013 07:40 AM
JaySVX
6.0L Power Stroke Diesel
8
Mar 7, 2013 11:24 AM
Snuggyworm
6.0L Power Stroke Diesel
14
Dec 17, 2012 08:26 AM
kord
1994.5 - 1997 7.3L Power Stroke Diesel
9
Oct 28, 2006 07:41 PM




All times are GMT -5. The time now is 08:58 AM.

story-0
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-02 21:45:57


VIEW MORE
story-1
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-05-30 18:33:59


VIEW MORE
story-2
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-3
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-4
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-5
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-6
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-7
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-8
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-9
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE