Yep, we stock them as well.

 

I thought I had seen them on your site, just didn't see it in the OEM section.

 

Slightly OT, what causes them to yellow the way they do? Is that a contaminant like fuel or just time and exposure to bad coolant (SCA was not maintained prior to me owning the truck)

 

It doesn't have to do with any "outside" stress. There is a line in front just above the seam across from the cap. It was noticable on the original bottle, the second one, and was not as bad on the third. I've been watching it, also replaced the pressure cap, and so far it's holding its own. The third one seems be molded from a different batch, as the mold stamp on it has some different numbers from the others. It may never spring a leak. At least, I hope it won't for a good while from now. I will try to post a picture later of the area in question.

 

Every related thread I've read on this forum and others says this crack always shows up in the exact same place. I was reading a chart on temperature tolerances of plastics and not even the mighty PEX (cross-linked polyethylene for hot-water plumbing in homes) can withstand the temperatures of boiling water at 15 PSI. Many durable plastics come up just short at 210 degrees. One could argue that it's unlikely there would be a straight shot of boiling hot water in the degas bottle - it should mix and cool right away. I theorize the hot water quickly goes to the top of the cooler water in the bottle and hangs there. And were is the top of the water? At that seam - directly above the water inlet.

Oh you are so going to hear from me soon.

I'm guessing that the yellowing is from exposure to all things Powerstroke, or more likely the dye in the coolant - but I'd welcome a chemist's input. The heating/cooling cycles can't be good for it either.

 

I do believe this has to do with the molding process. A weak spot is formed there. Look closely at any new bottle you purchase. As stated, all the bottles I've purchased from Ford had the same "stress line" in it above the seam. I have been running my coolant level slightly lower (just below the low level mark when cold), but when the coolant is hot,expands, and is still above the seam. In this case, I don't know if keeping the level below the stress point is having any effect on longevity, or not.

 

My thought was that's the line it goes to when hot. If I were to watch the bottle in the winter, that bottle would be at the min mark and a warm radiator would dump hot water instantaniously up into that freezing-cold plastic. This theory may not hold up well in Southern climates, but I wonder if there is a common denominator between those who have to replace the bottle frequently.

This spit-balling ideas is pretty cool.

 

This started out as a 1/4" line when the bottle was new.

 

I'm going to have one welded up and put a sight glass from Grainger on the side for level checking. The sight glass I have in mind is about $24. Gauge, Level/Temp, 5 In - Sight Gauges - Drums - 6W388 : Grainger Industrial Supply

 

I'm gonna make one of these up myself...all aluminum and shaped like the stock one so it will be a direct replacement

 

Go ahead and make two while you're at it! I'll send you my address.

 

Roland if it works out you will be the first to know
Only issue issee right now is the cap

 

I may just try this one when the time comes. Dorman makes some pretty good products. Less than $50 with shipping. 01 2001 Ford F250 Super Duty Expansion Tank - Cooling System - Dorman, Replacement - PartsGeek

 

I got a Dorman from Auto Zone. They ordered it for $38.00. It was there next day.

 

I am on my third unit and the crack appears at the same area on the first two. The good thing is that it is near the top and you do not loose any significant amount of coolant.
I too have considered fab'ing one from AL and using a sight glass similar to what is used on boiler feed water tanks. The cap should not be a problem as other AL radiators are set up in similar fashion. I have already traced a pattern out on a piece of card board. I have thought of using AL pipe that is cut to form the shape just like the OEM unit. I think this would go over big if someone can come up with a nice one.