How often do coolant reservoirs fail?
 

Mine did.:humm:
I have a thread about my coolant flush (15 total) and coolant filter install from the end of June this year. About one month ago at the beginning of August I saw lots of white residue on the driver side of the engine bay and suspected puking BUT the residue was lower than the reservoir cap. I did a little reading and discovered that several caps were failing due to an inability to hold 16psi. That's a cheap fix - although a mask if the true culprit is the dreaded HG failure.:td:
So a new cap and still a leak - BUMMER...but wait!:w2:
When I bought my upgraded cap, my service guy at the dealer recommended I get the reservoir as well based on my description of the coolant residue being low.:tu:
Today as I was warming up the transmission to replace the internal and external filters in preparation for tomorrow's flush I noticed a drip coming from the driver side - yes coolant, in a pin-sized stream from the bottom of the reservoir. I ought to have taken a video of the stream :pca1: but I just pulled the cracked reservoir and replaced it on the spot.:c:
Attachment 45357
The good thing is no HG failure AND perhaps another area for folks to check if you have puking.
Jonathan

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The crack is at the lower connection where the nipple joins the body...looks like a vertical white line under a vertical black line. The crack penetrated the entire reservoir allowing a needle stream to eject from the pressurized system. I was glad to have an aftermarket air cleaner because it was easy to pull out and give me access to the reservoir and clamp the coolant hose at the lower connection. I lost the coolant in the reservoir obviously but that was managable...no easy place to put a pan so I just used rags - mostly I think it will evaporate from the engine bay and then I'll pressure wash it again.:choochoo:

Its not really common but I have heard of them failing.

Yep, I too have heard of them and only seen one with my own eyes (excluding yours).

As usual, thanks for the great post with the pics to go with it!:c:

My work truck, 2005 F-550, 6.0L had the exact same thing happen. Related to this is the caps themselves. We have had a few caps fail, so the simple repair is a new cap. Well, when we get the new cap it won't screw on past half a thread. It seems over time the tank expands to the point when it enlarges the threads where the cap screws on. At this point an entire surge tank is required to accompany the cap. Fortunately it doesn't happen often.

I wonder if there is a problem with the caps that these tanks crack on? I mean the cap is meant to bleed off pressure if it builds too high (puking coolant), so how much pressure is that cap holding in in order to make the tank split?

Hmmm.....

That is a good point. In my case though, I had the coolant leaking from the crack with the original cap - not the improved one. While it did appear to be puking, the leak was not from the cap which is why I noted the residue below the level of the cap - that is to say that there was no residue at the cap and no residue where it would make sense...there was residue under the reservoir and on the bottom of the reservoir - conceptually it could run down (and I should have taken a photo to show this...a thousand words so they say).

I think the crack just got progressively worse independent of the old or new cap. I never did a pressure check:w2: - I mean for less than $10 to get a new cap seemed like almost a test in itself.:pca1: Of course it is throwing money at a problem without a genuine diagnosis.:argh:

I still haven't performed a pressure check on my own BUT I did have the transmission flushed yesterday (at 61,000) after I changed the external filter, internal filter, and transmission pan gasket (the original gasket was failing so it was worth it to sacrifice 8 qt of Mercon SP in advance of the flush).:ouch: The dealer hooked the truck up to their diagnosis computer and no mention was made of excessive pressure (or my tuner, or my aftermarket exhaust, aftermarket intake, aftermarket air filter, aftermarket intercooler, coolant filter, bypass oil filter, etc.).:w2:

On an unrelated note I also changed the transfer case fluid - I sent both the transfer case and transmission fluids in for spectrometal analyses.:pca1:

Jonathan:yeah:

I doubt it's pressure splitting the tanks but rather the heating and cooling cycles that make the plastic brittle to the point it cracks :c:

Let us know how you make out with those oil analysis.


Agreed, his tank does look "old and brittle"

I know this is an old thread, but my tank also cracked and the pic in this post is all but identical to what I found on my tank. Also My tank would not start to leak untill the truck was heated up. Then you would only get a very fine stream/mist from the crack.

Whistling sound from my resorvoir cap
 

Hey folks,

I have a 2006 F250 6.oL. Bobfbigman helped me a lot last time I posted due to a HPOP failure. In the past I have replaced the STC in the HPOP, EGR valve, EGR cooler, Turbo, glow plugs and wiring harness as well as injector harness and had the FICM rebuilt. My son and I also replaced the Standpipes and Dummy plugs.

This looks like a good place to start with my reservoir cap as well. I haven't actually seen a leak but I keep hearing a whistling sound and found when I put my hand on the reservoir cap, it's coming from there. Usually right after I turn the truck off as if it is depressurizing. I do periodically add fluid to the reservoir. Now it is whistling when I'm idling at a stoplight as well. Like it builds up pressure then leaks off. No water in the oil and everything else seems to work fine. Actually this has been going on for some time and now seems to be more frequent.

Thoughts Please???

Thanks in advance,

Whitey Cook: