Degas bottle

rthomas

Registered User
Joined
Jan 10, 2005
Posts
404
Reaction score
3
Location
Stanwood wa.
I'm on my way back from Idaho with a dump truck box on my gooseneck, this is my first heavyish long distance haul with this truck in a long time and I seem to be having a problem keeping my coolant up to level, it was fine unloaded but now fighting a strong headwind its going though just enough coolant to for the heater to go cold at an idle. Does an aftermarket degas bottle help with this?

Sent from my XT1650 using Tapatalk
 

79jasper

Chickenhawk
Joined
Oct 13, 2012
Posts
17,367
Reaction score
1,930
Location
Collinsville, Oklahoma
You might want to do a combustion gasses test on the coolant.... and get a cooling system pressure gauge rigged up.
Is it actually leaking? The caps can go bad also.

Sent from my SM-G892A using Tapatalk
 

rthomas

Registered User
Joined
Jan 10, 2005
Posts
404
Reaction score
3
Location
Stanwood wa.
You might want to do a combustion gasses test on the coolant.... and get a cooling system pressure gauge rigged up.
Is it actually leaking? The caps can go bad also.

Sent from my SM-G892A using Tapatalk
Oh.. I hope not.. ive not heard of a studded 6.0 blowing head gaskets, its coming from the either the cap or seam in the tank but
it still has pressure when I pull the cap

Sent from my XT1650 using Tapatalk
 

bismic1

Full Access Member
Joined
Mar 30, 2009
Posts
198
Reaction score
74
Location
Texas
They will always have pressure, just need to know how much. A pressure gauge teed into the vapor hose from the radiator is an important tool in troubleshooting. Highly recommended. To do it cheap on the road, you can get the parts from an autoparts store, except maybe you would need to get a gauge at Harbor Freight or something similar.

The degas bottle plastic does get brittle and crack although mine is still good at 200k miles. Probably depends on how hot it gets and for how long. If yours is leaking - replace it before worrying about head gaskets!

IMO the OEM degas bottle is an OK choice, but some have had issues with it and the OEM replacements they have bought. Still, they are WAY better than the Dorman alternative. If you are in a pinch, I think OEM replacement tank and cap is best. Part numbers below.

New degas (16 psig coolant overflow) bottle cap 9C3Z-8101-B
Degas bottle F series 6C3Z-8A080-B

If you want to go higher in pressure:
New 20 PSIG degas (coolant overflow) bottle cap 9S4Z-8100-B

As an fyi - studded trucks can still blow head gaskets. Depends a lot on the quality of machining on the head, the block preparation, and the assembly. Obviously it also depends on how hard the engine is worked also!

If you are putting combustion gasses into the degas bottle, you need to know that GO5 coolants can gel up being exposed to the low pH gasses. That can plug oil coolers and then you have more problems.

Do you have a way to watch your coolant and your oil temps? That is important also.
 
Last edited:

rthomas

Registered User
Joined
Jan 10, 2005
Posts
404
Reaction score
3
Location
Stanwood wa.
They will always have pressure, just need to know how much. A pressure gauge teed into the vapor hose from the radiator is an important tool in troubleshooting. Highly recommended. To do it cheap on the road, you can get the parts from an autoparts store, except maybe you would need to get a gauge at Harbor Freight or something similar.

The degas bottle plastic does get brittle and crack although mine is still good at 200k miles. Probably depends on how hot it gets and for how long. If yours is leaking - replace it before worrying about head gaskets!

IMO the OEM degas bottle is an OK choice, but some have had issues with it and the OEM replacements they have bought. Still, they are WAY better than the Dorman alternative. If you are in a pinch, I think OEM replacement tank and cap is best. Part numbers below.

New degas (16 psig coolant overflow) bottle cap 9C3Z-8101-B
Degas bottle F series 6C3Z-8A080-B

If you want to go higher in pressure:
New 20 PSIG degas (coolant overflow) bottle cap 9S4Z-8100-B

As an fyi - studded trucks can still blow head gaskets. Depends a lot on the quality of machining on the head, the block preparation, and the assembly. Obviously it also depends on how hard the engine is worked also!

If you are putting combustion gasses into the degas bottle, you need to know that GO5 coolants can gel up being exposed to the low pH gasses. That can plug oil coolers and then you have more problems.

Do you have a way to watch your coolant and your oil temps? That is important also.
Thanks, I have an edge monitor and the oil is stay within 10* of the coolant, I only have 25-30k on the studs 195 total, and I'm pretty nice to it, I keep it around 1100 on the hills. Ill see if I can hunt down a new one before we get on the road this morning, thanks for thr the part #s

Sent from my XT1650 using Tapatalk
 

bismic1

Full Access Member
Joined
Mar 30, 2009
Posts
198
Reaction score
74
Location
Texas
Glad your oil temps are good and that you monitor them. I guess I am also saying that, even though the temps are good now, you don't want to start to develop a problem.

What coolant are you using?

Ford coolant, and all G05 coolants, will react with combustion gasses and at some point (who knows when exactly) gel.

With the constant loss of coolant, you are working that coolant pretty hard, so you want something very robust in there. EC-1 rated ELC coolants are probably the best to use.
 

rthomas

Registered User
Joined
Jan 10, 2005
Posts
404
Reaction score
3
Location
Stanwood wa.
Hahahaha haven't been around 6.0's long then.
It seems a diy stud install last longer than a "performance shop" install. Can't say why.

Sent from my SM-G892A using Tapatalk
If it is HG then its gone, ill go get a new 6.7, I'm not doing that again. I did a massive amount of research on 6.0s before I bought this truck and for what I do I shouldn't have hg issues.

Sent from my XT1650 using Tapatalk
 

rthomas

Registered User
Joined
Jan 10, 2005
Posts
404
Reaction score
3
Location
Stanwood wa.
If it is HG then its gone, ill go get a new 6.7, I'm not doing that again. I did a massive amount of research on 6.0s before I bought this truck and for what I do I shouldn't have hg issues.

Sent from my XT1650 using Tapatalk
Made it home last night, replaced degas and cap with a new ford one, didnt really change much but I did figure out that it was only blowing out the contents of the bottle, if I added about a pint of coolant it would get the level up to the very bottom of the degas. Also talked to the shop that did the bullet proofing, they want to have a look at it just to make sure but they dont think I have a problem, they attribute it to the load and my fan coming on a little late some of the time (most of the time 215ish a few times 230) it did work its ass off, I averaged 7.6 mpg on the return.

Sent from my XT1650 using Tapatalk
 

bismic1

Full Access Member
Joined
Mar 30, 2009
Posts
198
Reaction score
74
Location
Texas
How much weight are you towing?

230 is definitely high for the coolant temp. The Ford strategy will start to defuel above 221 *F coolant temp.

Maybe you have a fan clutch issue or maybe the water pump is weak, but over pressuring the degas bottle will impact the coolant flow and cause overheating .... so you need to figure out which is the cause and which is the effect!

Since you made it home, I would do some testing unloaded to see what is going on. A coolant pressure gauge would really help you IMO. The shop may be correct, but that is what I would expect them to say at first since they did the head stud work.
 

rthomas

Registered User
Joined
Jan 10, 2005
Posts
404
Reaction score
3
Location
Stanwood wa.
How much weight are you towing?

230 is definitely high for the coolant temp. The Ford strategy will start to defuel above 221 *F coolant temp.

Maybe you have a fan clutch issue or maybe the water pump is weak, but over pressuring the degas bottle will impact the coolant flow and cause overheating .... so you need to figure out which is the cause and which is the effect!

Since you made it home, I would do some testing unloaded to see what is going on. A coolant pressure gauge would really help you IMO. The shop may be correct, but that is what I would expect them to say at first since they did the head stud work.
It wasn't so much the weight, I'll guess we were grossing 18-20, but the headwind/hills/bad aerodynamic load were the big thing, box facing forward, cabguard grabbing extra air.

Sent from my XT1650 using Tapatalk
 

G. Mann

Full Access Member
Joined
Apr 13, 2007
Posts
927
Reaction score
86
Location
Phoenix, AZ
A shop that has loads of 6.0 experience told me this.
EVERY 6.0 engine that came in with a blown head gasket, had a radiator cap that had failed, and the cause for the blown head gasket WAS the bad radiator cap... He explained it this way:

Coolant pressure raises the boil point of coolant, so a 16 lb cap lets temp of coolant in radiator rise to 280 degrees before it boils. Cooling fan clutch is built to kick in at, say 230 degrees, and cool radiator...

Cap pressure failure does this.. it lowers the coolant boil off temperature, to a point BELOW the fan clutch kick in point, so at, say 6 lbs pressure, the boil off temp lowers to, say 218 degrees... the fan clutch does not kick in the fan... coolant boils off, less coolant causes bad cooling at head and cylinder walls... temp rises higher... more coolant boils off... spews out the Degas tube overboard as steam and hot water, which exits below the sight line of the driver ... engine cooks.. while the fan clutch is waiting to reach it's "kick on the fan point".... but the coolant boils off before it ever does.

His advice.... Replace the radiator cap [degas cap] at EVERY oil change interval... and ONLY USE Motorcraft caps... New caps cost less than $8.. cheap insurance.

I immediately tested the radiator cap on my 2005 F350 6.0 dualy.. which had been losing coolant around the cap [look for residue] ... sure enough... it was bad... Ford, in it's wisdom to save pennys, uses the same cap of a bunch of it's small engine cars and trucks... it's not up to the task of the diesel system... Use it.. throw it away... put in a new one... OFTEN. Every oil change is now my rule.
 

bismic1

Full Access Member
Joined
Mar 30, 2009
Posts
198
Reaction score
74
Location
Texas
PowerStrokeHelp.com dramatizes things. That degas cap is not the root cause of all the 6.0L headgasket issues.

The funny thing about circular logic. When head gaskets blow, they over pressure the degas bottle and the cap relieves. When the cap relieves (and the gas and liquid is hot), it weakens the spring. This happens in industry as well, but probably more so w/ the Ford caps because the spring is pretty marginal. Anyway, with that cause-and-effect going on, every head gasket problem will also have a weak cap. Doesn't mean the weak cap is the root cause.

If it were, there are a lot of shysters out there charging to o-ring heads and install studs. Even Bill installs o-ringed heads and studs.

With regards to the fan clutch, it is always turning the fan (at least at a 350-400 rpm minimum). It will speed up based on several engine temperature parameters (coolant, oil, transmission). It will pretty much be full on at 220 degrees. The Ford strategy begins to de-fuel at 221 degrees. The fan will be running pretty hard (if not at full speed) prior to 221 *F.
 
Last edited:

Thewespaul

Supporting Member
Supporting Member
Joined
Jul 27, 2015
Posts
8,796
Reaction score
8,058
Location
Bulverde, Texas
Instead of the cap causing the hg failure, maybe the hg failure killed the cap? High pressure in the cooling system from combustion gasses can put a hurting on a plastic cap.
 
Top