Coolant Overflow Tank Fail!

[Aerialfred]

Since we are on the cooling system, I have a question. Got my 998 started today for the first time and it ran great, but after 10 minutes the temp. guage was reading 200 and climbing! What are they supposed to run at? And should I go ahead and pull the thermostat to swap a new one in? The truck has sat for 3-4 years. Or could it possibly be an air bubble that will need to be worked out?

 

[o1951]

Here's the culprit. The previous owner painted the tank black and the age cracking wasn't seen until i removed some of the paint to investigate the leak.

Painting it black makes it look nice, but the solvent in the paint can cause the plastic to age and crack.

On a side note, I think people are overly concerned about coolant recovery tank failure. I have had failures on civy cars and trucks (that I did not own)- usually the hose to the tank blows at a nipple. Have always been able to continue to my destination, and more.

The purpose of the tank is to capture coolant expelled due to expansion, and return it when the engine cools down, keeping air out of the cooling system. There should not be any draw back until the engine cools, so recovery tank failure , other than the stink and mess it makes, will not cause the engine to overheat.

 

[SublimeMudTime]

When it looks like it's running hot, turn it off, wait 10 seconds and start it again. In my experience, it will read a normal temp...

 

[DatGuyC]

Painting it black makes it look nice, but the solvent in the paint can cause the plastic to age and crack.

On a side note, I think people are overly concerned about coolant recovery tank failure. I have had failures on civy cars and trucks (that I did not own)- usually the hose to the tank blows at a nipple. Have always been able to continue to my destination, and more.

The purpose of the tank is to capture coolant expelled due to expansion, and return it when the engine cools down, keeping air out of the cooling system. There should not be any draw back until the engine cools, so recovery tank failure , other than the stink and mess it makes, will not cause the engine to overheat.

The difference here is that the plastic recovery tanks on civilian cars and trucks are not under pressure, it is only there to catch overflow coolant. In the hmmwv/hummer it is part of the cooling loop and under pressure, so when it cracks your whole cooling system looses pressure and all your coolant sprays out from the crack.

 

[Retiredwarhorses]

Painting it black makes it look nice, but the solvent in the paint can cause the plastic to age and crack.

On a side note, I think people are overly concerned about coolant recovery tank failure. I have had failures on civy cars and trucks (that I did not own)- usually the hose to the tank blows at a nipple. Have always been able to continue to my destination, and more.

The purpose of the tank is to capture coolant expelled due to expansion, and return it when the engine cools down, keeping air out of the cooling system. There should not be any draw back until the engine cools, so recovery tank failure , other than the stink and mess it makes, will not cause the engine to overheat.

You must have pressure in the tank to keep the cooling system working as it was desigend. Loss of pressure will raise the coolant temp and make the truck run hot, and even possibly overheat. A Bad coolant tank cap or one rated at more the 15 psi will do the same.

 

[gcbennet]

So this is what happened (photo) with the new tank (literally only 3 weeks old) I installed. I was rolling in a local Santa Claus parade and about 2/3 the way through began overheating to the point where coolant was venting out the discharge hose. I've been in my share of parades with MV's, and although the humvee doesn't like to idle much for lengths of time I wasn't terribly concerned just yet, so i kept rolling. The system was doing what it was designed to do and at the time of the mishap I was literally only a few hundred metres from the end. Suddenly there was a loud 'pop' and the whole truck was enveloped in an enormous, thick, white steam cloud. I discovered afterwards that the the new overflow tank had actually ruptured, spewing hot coolant all over the top of the hot engine. Losing SA for about 5-10 seconds in complete white-out while on the move was scary enough. But, coincidentally I happened to be directly in front of the fire dep't when it happened and immediately pulled into their driveway to the whoops and cheers of the spectators who thought it was all part of the fire dept's show. Anyhow, on a good note Woolfer was very accomodating and sent a replacement tank in the mail right away from what they claim is a tested lot. We'll see. Either way, I've learned my lesson and will not be rolling the beast in any more long parades where the threat of overheating might occur.

 

[Retiredwarhorses]

Gordon this has been talked about before...and as I said before, unless you are buying genuine NOS parts, you are getting chinese knock offs...I WILL NOT use wolfer surge tanks or washer bottles...they do nothing but fail.

as it goes for long idling and parades etc...you have issues with you cooling system if your truck is overheating...under any circumstances.

 

[DatGuyC]

When the one I got from them cracked they offered to send me another, I said no way and just got my money back. Its worth it for the aluminum tank, no worries at all.

 

[o1951]

From experience - it can be pressure tested cold and be fine, which may be what they are doing.
The key is what happens when HOT antifreeze stays there for a while and builds up pressure. You can test with hot water and be fine, but hot antifreeze is a different situation.

If you want to keep the new tank, suggestions: find out why overheat- dirty radiator or blocked cores?
Too small a fan?

The last thing - perhaps mod so that less pressure builds up in tank.

 

[gcbennet]

The guy i talked to at Woolfer claims their overflow tanks are US made surplus, so i'm not sure what's going on there considering the one I replaced in my truck was 30 years old. The fan system works fine and it runs at normal temps during normal use. Perhaps there's some partial blockage or sedimentary buildup in the rad or elsewhere. When I cleaned-out the heater core a while back a lot of solidified brown chunks were coming out as I banged it, so it's possibe this may be a greater systemic issue.

 

[o1951]

The guy i talked to at Woolfer claims their overflow tanks are US made surplus, so i'm not sure what's going on there considering the one I replaced in my truck was 30 years old. The fan system works fine and it runs at normal temps during normal use. Perhaps there's some partial blockage or sedimentary buildup in the rad or elsewhere. When I cleaned-out the heater core a while back a lot of solidified brown chunks were coming out as I banged it, so it's possibe this may be a greater systemic issue.

Well, most of my experience with old stuff is civy, but an engine is an engine, and a radiator a radiator. As things deteriorate, Cars/ trucks - find out something is marginal when they get stuck in heavy traffic crawling along. Emergency measures - put heater on high and open windows. Pop hood and leave slightly open on safety catch. Later - check radiator for blocked cores - mud or leaves in lower section, have radiator professionally rodded out. Sometimes, when all the internal crud is removed, leaks show up, and the best course is a recore.. The crud was plugging the bad spots.

The solidified brown stuff could be something like Bar's stop leak. That is what we see when someone puts it in to try and seal leaks. The sealer settles in areas of low flow and solidifies. I hate that stuff. Have had to dismantle engines and have block & heads hot tanked to get it out and restore normal cooling.

 

[gcbennet]

So I got a message from Woolfer recently stating that in response to the rash of failures they have pressure tested over 300 of their coolant tanks and all have failed, forcing 'discussions with the manufacturer'. I got my new replacement tank from HPG and there were marked differences from the word go. Seeing as HPG is a bonified AMG parts supplier I'm sure what I got is new and legit. The colour difference was the first thing to stand out. Woolfer's was off-white whereas HPG's was pure white. Age faded or different plastic composition? Who knows. There was also a distinct absence of mold flashing in the return ports on the HPG tank as well. The HPG tank also has way more alpha-numeric info molded onto the tank body itself. Just food for thought.

 

[86humv]

A couple photo's of them side by side would be nice if you can.

 

[o1951]

So I got a message from Woolfer recently stating that in response to the rash of failures they have pressure tested over 300 of their coolant tanks and all have failed, forcing 'discussions with the manufacturer'..

Well, good for them. Sound like reputable people! Many companies would try to bury issue, like GM did with ignition switches.

 

[Retiredwarhorses]

Well, good for them. Sound like reputable people! Many companies would try to bury issue, like GM did with ignition switches.

Don't kid yourself....I have had no less then 2 bottles and 3 washer bottles fail from them.
never got an ounce of help from them...I just don't buy wolfer crap.

 

[tigertank]

HPG hummer parts guy? I see them on sale for 200 or a low coolant sensor one for a little less is this the one u got from them.... and how do we know which one to get??

 

[gcbennet]

I got the one without the sensor. $200 was a bit pricey, but I suppose the piece of mind is worth it.

 

[gcbennet]

There's the burst tank and the new one. You can see the obvious colour difference. The cap receptacle on the Woolfer tank was ready to fail under pressure as well, as can be seen by the lifting ring.

 

[tigertank]

Thx gordon