idi traveler
Full Access Member
What is the purpose of the rubber band around the body of the thermostat?
thermostats
- Thread starter idi traveler
- Start date
f-two-fiddy
Registered User
To seal it.
idi traveler
Full Access Member
I don't understand. Wont it just get hard and crumble away over time.
I could, but I've never seen or heard of that being an issue before. The T-stat I took out of my crew cab had 300+K on it and the rubber was intact and without cracks.
Heath
Heath
idi traveler
Full Access Member
Damn the luck. It turns out that my old engine didn't have a t-stat and the new one that I freshen up has one with only a couple of pieces of the rubber band left.
icanfixall
Official GMM hand model
I cut off that rubber seal so I have more coolant flow around the thermostat. Yes, its there to seal off the coolant flow thru the thermostat but watch how they open in a pan of hot water. My leak thru is not an issue and I have run like this hauling heavy all over the US and Canada. If you really want to help these 7.3 engines run cooler just use a 6.9 head gasket instead of the 7.3 head gaskets. Look at the lower edge of the 7.3 heads and the block. There is a coolant passage plugged up. Remove the plugs and use a 6.9 gasket and there will be more coolant flow thru the heads. I have researched both gaskets and only find the passage open in the 6.9 gaskets. No reason for it plugged up in the 7.3 except someone wanted a hotter running engine for emmissions probably. I know a hotter running diesel gets better fuel milage but too hot like what many here are experiancing is something to look at closely. All the heads are the same bolt patterns so a 6.9 drilled out will fit a 7.3 block. The only differance in the 6.9 and 7.3 gaskets is the coolant passage. I have measured every coolant port and bolt hole so I know they will work. Even the thickness is the same. Now are they made from the same material... Sure are. They run the same coolant... The same fuel... The same compression ratio... And the fire ring bore is exactly the same.... I think we are on to something here... I sure wish somebody was a for ingineers that had something to do with the building of these engines.. Be real nice to viedo a talk with them...
Black dawg
Registered User
I have seen several of those rubber bands come apart and cause issues.
idi traveler
Full Access Member
I cut off that rubber seal so I have more coolant flow around the thermostat. Yes, its there to seal off the coolant flow thru the thermostat but watch how they open in a pan of hot water. My leak thru is not an issue and I have run like this hauling heavy all over the US and Canada. If you really want to help these 7.3 engines run cooler just use a 6.9 head gasket instead of the 7.3 head gaskets. Look at the lower edge of the 7.3 heads and the block. There is a coolant passage plugged up. Remove the plugs and use a 6.9 gasket and there will be more coolant flow thru the heads. I have researched both gaskets and only find the passage open in the 6.9 gaskets. No reason for it plugged up in the 7.3 except someone wanted a hotter running engine for emmissions probably. I know a hotter running diesel gets better fuel milage but too hot like what many here are experiancing is something to look at closely. All the heads are the same bolt patterns so a 6.9 drilled out will fit a 7.3 block. The only differance in the 6.9 and 7.3 gaskets is the coolant passage. I have measured every coolant port and bolt hole so I know they will work. Even the thickness is the same. Now are they made from the same material... Sure are. They run the same coolant... The same fuel... The same compression ratio... And the fire ring bore is exactly the same.... I think we are on to something here... I sure wish somebody was a for ingineers that had something to do with the building of these engines.. Be real nice to viedo a talk with them...
I wish I had know when I freshen this motor. If this motor that I took out can be resleeved I'll I well certainly use 6.9 head gaskets. I'll test this t-stat and if it works I'll go ahead and use it. If it over heats or runs warmer than I'll order a motorcraft t-stat from rock auto. Ford and IH will have to order one for about $30. Rock has Motorcraft $18 shipped.
icanfixall
Official GMM hand model
Idi Traveler. What I attempting to say is I have done lots of research into why the 6.9 engines have more coolant passages thru the heads and block. But the 7.3 engines have those areas plugged off and the 7.3 head gaskets don't have the coolant passages in the lower front and baxks of the heads or block. The 7.3 has what looks like about a 5/8 inch freeze plug in the block and heads. The question I put out is why is this area machined and then plugged up where its cast directly into the 6.9 engines... And they generally run much cooler longer than we can climbing a grade. I'm guessing I should do a viedo or take some pics so al will see and understand what I feel will make our 7.3 engine pull heavier loads and not heat up so quickly.
idi traveler
Full Access Member
Do you think we could pull those plugs in the block and heads and use the 6.9 gaskets and be in business. I will be pulling a 35' goose neck that weighs 7000 give or take and 20 to 26 round bales of hay, depending on what my truck can handle. I like cool when I look at my temp gauge.
My bad! You are running that way. Sorry for my not reading close enough.
My bad! You are running that way. Sorry for my not reading close enough.
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idi traveler
Full Access Member
I looked at my dead engine and heads today. Sure enough little freeze plug looking things in the cylinder deck front and rear both sides and corresponding locations in the heads. Go figure, it's much better to burn cleaner than to last longer!
They went to a lot of lengths to make these things run HOT to lower the fleet emissions ratings. The factory fan clutches don't completly lock up till just a handful of degrees below where the overtemp light goes off 
idi traveler
Full Access Member
This just keeps getting better. Do we need a thread where everybody that has any info on how to make these things run cooler and more reliable? All the tricks that don't cost an arm and a leg, that is within the reach of everybody. But also like what RLDSL has done with the fans and waterless coolant. ICANFIXALL is what all of us can do, because one day we all will have our heads off!
