The Diesel Stop banner
1 - 9 of 9 Posts

·
Registered
Joined
·
169 Posts
Discussion Starter · #1 ·
Ok, so changing out thermostat housing, I anti-seized the bolts that came in billet housing, tourqed them to 15ft/lbs and twisted one off. End to a long day, was able to salvage by backing out before complete separation. I have heard anti-seize can change tourque reading but what bolt can't take 15. I may have done something wrong but not sure. I have had this happen on a bolt while changing diff cover thought it was bad quality bolt but maybe I suk as mechanic
 

·
Super Moderator
Joined
·
12,011 Posts
There are a lot of bolts that can't take 15 lb-ft. You've identified two of them. And anti-sieze is a lubricant. A lubricated bolt at 15 lb-ft is significantly tighter than one without lube.
 

·
Premium Member
Joined
·
1,415 Posts
I put a tiny bit of anti-seize on mine and had no trouble, 3 times now. Have you had your torque wrench calibrated lately? Also keep in mind if you are using a big torque wrench that goes to a high number your accuracy range will be broader and different at lower values.

As a side note Dieselsite only recommends 100-110 inch pounds on their billit housing, which is less than 10 ft lbs. Billet Aluminum Thermostat Housing | Ford 7.3L Powerstroke | Diesel Site
 

·
Premium Member
Joined
·
1,415 Posts
This is what I am trying to say about a torque wrench that goes to a high value when used at a low value. From the StangTV site written by a torque wrench expert. That is why it is best to use a very small torque wrench like the ones for inch lbs on small fasteners. (read the attached thumbnail)
 

Attachments

·
Registered
Joined
·
169 Posts
Discussion Starter · #5 ·
Did not see any recomendation from them in on torque values would of helped. The stock bolt was 17 ft/lbs but with thicker housing can see a lesser value. Lesson number? Lost count already
 

·
Premium Member
Joined
·
1,415 Posts
Did not see any recomendation from them in on torque values would of helped. The stock bolt was 17 ft/lbs but with thicker housing can see a lesser value. Lesson number? Lost count already
That may have helped but I still suspect the lubrication combined with an inaccurate torque wrench may be the problem.
 

·
Super Moderator
Joined
·
26,497 Posts
How many times have the bolts been reused? That makes a difference as well, because the bolts are stretched just a bit each time they're tightened. It's similar to bending a piece of wire multiple times till it breaks. As was said, anti-seize makes the bolts tighter than they would be if torqued dry. The torque spec for the water pump bolts is 18 ft-lb and those bolts are one size larger than the thermostat bolts, so 15 ft lb is much larger when compared to the difference in cross section area of the bolts.
 

·
Registered
Joined
·
169 Posts
Discussion Starter · #8 ·
They were brand new bolts, will avoid anti-sieve till absolutely needed. Reset new bolts to 10 ft/lbs and more bed on to next project.
 

·
Premium Member
Joined
·
15,097 Posts
Or, you can do the RT mod- get 3 stainless grade 8 bolts about 10mm longer than you need. Cut the heads off and Loctite the studs into the water pump. Use stainless nuts on your housing. Never worry about breaking a bolt off again.


Sent from AutoGuide.com Free App
 
1 - 9 of 9 Posts
Top