Changing Degas Bottle

[02LincLS]

If you filled right to the top, it will blow the extra out the cap. If it does it again the next day, you may have not got all the air out of the system. Or there is still a leak in the system, preventing pressure from building and lowering the boiling point of the coolant. Less likely is the cap venting too soon.

I have the doorman tank and the cap is suppose to click. Its cheap though- sometimes it does and sometimes it doesn't. The cap is suppose to relieve at 16 psi so as long as its turned on tight enough to hold that, you should be good... roughly comparable to the force required to click the oil cap. I did crank mine at one point and you'd need two hands and some good elbow grease to strip it.

 

[LJS30]

Well I'm going to let it cool and cinch the cap down again. If I still have an issue but cannot see any leaks anywhere else in the system then it must be the cap?

 

[joegr]

No, there are other possibilities to.

Where did you fill the bottle to before this happened? If it was over the hot fill line, then it is expected for it to vent the excess coolant when it heated up.

If you have an air leak in the system, it could cause this.

If you didn't fill and bleed by the letter of the procedure, it could cause this.

...

 

[LJS30]

Well Joegr here is what occurred. We finished it on Monday and I drove it as is to work and back several times. That's about twenty miles in 95 to 100 degree heat. Everything seemed okay as the fluid level was right at the tip of the hot fill line or a bit below. I was curious about the cap so I unscrewed it this morning and drove to work without issue. On my way home though it was really hot outside and once I got home is when I saw the fluid leaking out the top. Did I mess something up by taking the cap off and putting it back on this morning?

 

[joegr]

... Did I mess something up by taking the cap off and putting it back on this morning?

No.

 

[LJS30]

Okay so air still in the system due to improper bleeding. So I bleed again and see what happens. If this occurs again then possibly a malfunctioning cap? So I change the cap. If this occurs once again then where do I go from here? Thermostat? Then water pump? Then?

 

[joegr]

What parts haven't you changed? It's been said several times. Change them all at once if you want to be worry free (cooling system wise) for the next 5 to 7 years.
Change one thing at a time if you want to be working on it (and buying coolant) over and over again for the next several months.

 

[LJS30]

Well Joegr now I have changed the cap, the degas bottle, lines going to the degas, and now the T-stat. It seems okay now as I drove it quite a bit without any issue today. So next is the water pump.

 

[RigsLS]

Why are you changing out the water pump?

 

[LJS30]

Well it seems like the only way to trust this car at all in terms of cooling is to totally replace the system correct? So I am thinking why not just go balls deep and do the whole thing.

 

[RigsLS]

Water pumps are not the issue, Auxiliary Coolant Flow Pump on 1st GEN is.
Replacing the radiator also? ... also not most common problem.

When the forum recommends replacing the cooling system parts, they do mean the plastic plumbing which makes up 85% of the entire system and it's only recommended due to it's age where it begins to deteriorate/break-down. Degas bottle, in and outlet pipes, Thermostat housing and stat, DCCV and Auxiliary Coolant Flow Pump, couple of hoses and you're onto bleeding the system to new condition. Do it right, do it once! no need to replace water pumps or rads unless they are giving you problems.

If you have a close look at some of these plastic cooling system parts, you'll notice that it's turning brown in color, deteriorating ends where clamps go, or on the inside you may notice brown pitting starting to develop. Anything plastic like that, which is going on 10+yrs old, subjected to heat cycles and chemicals is bound to come apart eventually, no matter what brand/make/model.

I say, leave the water pump alone unless you actually have a problem with it, which I bet you don't.


PS: if you have the 1st GEN do yourself a favour and replace the Thermostat housing with the cheaper all aluminum Jaguar housing.

Re&Re - Jag Aluminum Upgraded Thermostat housing - GEN 1 V8


GLWR

 

[1LoudLS]

I will say that I have seen more people having problems with their radiator in the past year then I have noticed before...

so while it may not be one of the most common points of failure, it is a plastic cooling part, and is subject to the same kinds of failures as everything else

 

[RigsLS]

Suppose it might be but would you at least agree it doesn't top the list everyday. Mines original and holding up fine (knock on wood)

 

[1LoudLS]

you're right that it would not be something I would do in round one... but if I replaced everything else and was still having problems, I wouldn't rule it out.

 

[joegr]

I will say that I have seen more people having problems with their radiator in the past year then I have noticed before...

so while it may not be one of the most common points of failure, it is a plastic cooling part, and is subject to the same kinds of failures as everything else

Well, they are getting older. I think that it's a question of when, not if.

 

[LJS30]

Then after this I should have 100,000 miles of trouble free service?

 

[LJS30]

On a more funny note why is it called the Degas Bottle? Was there a man name Alfred P. Degas that invented this gem of work?

 

[joegr]

On a more funny note why is it called the Degas Bottle? ...

De-gas
Because that's the main thing that it does - remove gas (air and steam) from the coolant.
The small hose that runs to the top side of it from the engine is the engine air bleed. Any small amount of air (steam usually) that forms in the engine cooling loop should bubble out of the tube that runs to the bottom of the degas bottle, and vent out though the pressure relief in the cap.

From the service manual:
The degas bottle:

provides a location for system fill.
contains coolant expansion and system pressurization.
provides air separation during operation.
replenishes the engine coolant to the system.

 

[LJS30]

Ahhhh I see. Design advantage or design flaw?

 

[LS4me]

Ahhhh I see. Design advantage or design flaw?

Necessity......

 

[joegr]

Ahhhh I see. Design advantage or design flaw?

Neither. As LS4me said, you have to have it. If it were a brick shaped car where the top of the radiator could be above the top of the engine, then you could leave some air space in the radiator, and you wouldn't need it. Fortunately, they don't make cars like that anymore, so a degas of one form or another is needed.