Radiator

MR47930

Member
Driving home from work on rt 4 on the st Mary's side. Saw a guy pull on the right hand shoulder with his hood up and a huge, what I thought was smoke cloud, coming from his hood. As I passed I saw another guy frantically pouring water on another guys face. I assume what I thought was smoke was actually the steam from his radiator? Really hope he didn't pop the hood and try to open it after driving. Anyone know what happened and if the guys is ok?
 
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DEEKAYPEE8569

Well-Known Member
Sounds like the guy getting water poured onto his face popped the radiator cap and got a face-full of overheated coolant. If your car has an overflow tank and a radiator cap, just loosen the cap on the overflow tank enough to release pressure; keeping the face out of the way, of course. NEVER pop the cap on an overheated radiator.
 

Hannibal

Active Member
Driving home from work on rt 4 on the st Mary's side. Saw a guy pull on the right hand shoulder with his hood up and a huge, what I thought was smoke cloud, coming from his hood. As I passed I saw another guy frantically pouring water on another guys face. I assume what I thought was smoke was actually the steam from his radiator? Really hope he didn't pop the hood and try to open it after driving. Anyone know what happened and if the guys is ok?

Most likely the case. I can't fathom how people don't understand this concept or were never informed at some earlier part in their life (drivers ed?). Hell, most, if not all, cars have a diagram on the engine bay, radiator cap and overflow box.

A couple weeks back, my brother ..... a highly educated / fairly high ranking Fed Gov't employee .... had his car overheat on Suitland Pwky heading home. I told him I'd head that way in the event he needed a hand. A few minutes later, he called me from the parking lot of a Napa and was asking me what "hole" he needed to pour the coolant into because the labels were faded and he wasn't sure. Had he not been unsure (or the labels were clear), his intent was to crack the radiator open and fill her up. By the time I got there 20 minutes later, she was still hot, still under pressure and it took another 30 minutes before it was safe to open. He'd had been another burn victim if he didn't think to call.
 

Gilligan

#*! boat!
PREMO Member
Sounds like the guy getting water poured onto his face popped the radiator cap and got a face-full of overheated coolant. If your car has an overflow tank and a radiator cap, just loosen the cap on the overflow tank enough to release pressure; keeping the face out of the way, of course. NEVER pop the cap on an overheated radiator.

An overflow tank is not pressurized to begin with. And you can usually hear the racket from a full-blown overheat venting noisily in to the overflow tank..and even making the overflow tank overflow...

A close friend of mine's face and neck are permanently scarred from exactly that kind of incident many years ago. He spent some time in a hospital as a result...steam burns are nasty.
 

Forkian

Member
Surprised car manufacturers haven't installed some type of safety measure to prevent burns from opening a hot cap.
 

DEEKAYPEE8569

Well-Known Member
An overflow tank is not pressurized to begin with. And you can usually hear the racket from a full-blown overheat venting noisily in to the overflow tank..and even making the overflow tank overflow...

A close friend of mine's face and neck are permanently scarred from exactly that kind of incident many years ago. He spent some time in a hospital as a result...steam burns are nasty.
I know it's not pressurized. The radiator is. The overflow tank is there to collect the expanding coolant that is heated by the engine and recycles it back into the coolant system once it loses enough heat . What I'm saying is, DON'T immediately unscrew the radiator cap (if so equipped) on an overheated radiator. Stop, open the hood, wait for the "the racket" to stop, THEN very slowly unscrew the overflow tank cap just enough to release the hot water/air pressure, while keeping hands/faces away.
 

black dog

Free America
Surprised car manufacturers haven't installed some type of safety measure to prevent burns from opening a hot cap.

Radiator caps have had a double lock on them and or a safety lever for 60 plus years.. Folks need to learn to read.. Kinna like filling up a HOT engines cooling system, Its all good until it blows back 200* plus water in your face while you are looking down at the radiator.
 

DEEKAYPEE8569

Well-Known Member

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black dog

Free America
Don't know if they're still used; or if they're even still made, but years ago, there was a radiator cap with what amounts to a pressure release tab. In the event of an overheat, pop the tab and stop back while the pressure abates.

They are still being made, Thats why regular caps have a double lock on them. You can take a rag and use it like a pot holder and turn the cap about a 1/8th of a turn and it will release the pressure along with some antifreeze.. Its safer to let it cool for 30 min.
 

Gilligan

#*! boat!
PREMO Member
I know it's not pressurized. The radiator is. The overflow tank is there to collect the expanding coolant that is heated by the engine and recycles it back into the coolant system once it loses enough heat . What I'm saying is, DON'T immediately unscrew the radiator cap (if so equipped) on an overheated radiator. Stop, open the hood, wait for the "the racket" to stop, THEN very slowly unscrew the overflow tank cap just enough to release the hot water/air pressure, while keeping hands/faces away.

I was responding to this
just loosen the cap on the overflow tank enough to release pressure

But yeah..loosening the radiator cap too soon is never a good idea if overheating is suspected. What happens is that the superheated coolant (say 255 degrees plus) is prevented from boiling and becoming steam only because of the 15 psi or more of pressure it is under. You release that pressure and BAM!...instantaneous steam explosion.
 

DEEKAYPEE8569

Well-Known Member
They are still being made, Thats why regular caps have a double lock on them. You can take a rag and use it like a pot holder and turn the cap about a 1/8th of a turn and it will release the pressure along with some antifreeze.. Its safer to let it cool for 30 min.
Agreed.
 

Clem72

Well-Known Member
Surprised car manufacturers haven't installed some type of safety measure to prevent burns from opening a hot cap.

Well they already say "Do not open when hot". Guess you could make them Red, or put another cap under the first one that pops up when the pressure is high and says "What the hell did I just tell you!"
 

Gilligan

#*! boat!
PREMO Member
Well they already say "Do not open when hot". Guess you could make them Red, or put another cap under the first one that pops up when the pressure is high and says "What the hell did I just tell you!"

Wait for it.

The danger is greater than ever as manufacturers has pushed the normal operating temperature up and up over the years. Current modern vehicles often have normal temp range well exceeding 212 degrees. You could - and probably will - experience a coolant flash if popping the radiator cap on a newer vehicle even when the guage shows it's within the normal range.
 
Wait for it.

The danger is greater than ever as manufacturers has pushed the normal operating temperature up and up over the years. Current modern vehicles often have normal temp range well exceeding 212 degrees. You could - and probably will - experience a coolant flash if popping the radiator cap on a newer vehicle even when the guage shows it's within the normal range.

Mine is 219-220*
 

MR47930

Member
Hopefully the guy is alright but like everyone has stated, not sure how this isn't common knowledge. Worked at a service station in high school and saw this a few times from grown men. That's a lesson you DONT want to learn the hard way.
 

spr1975wshs

Mostly settled in...
Ad Free Experience
Patron
My dad was laid up for a week in the hospital and 3 weeks at home when I was about 9 or 10, steam burns at work.
He was an industrial boiler and furnace repairman. Old pipe gave way.
 

MR47930

Member
My dad was laid up for a week in the hospital and 3 weeks at home when I was about 9 or 10, steam burns at work.
He was an industrial boiler and furnace repairman. Old pipe gave way.

Sorry to hear that. I'm convinced that there is no greater physical pain than a severe burn. Had a good 2nd degree burn on my hand when I was younger and the pain was unbelievable. Felt like someone was constantly putting a match out on my skin. This was a very small burn so I couldn't imagine the pain someone must feel with severe burns on a large section of their body.
 

glhs837

Power with Control
Hopefully the guy is alright but like everyone has stated, not sure how this isn't common knowledge. Worked at a service station in high school and saw this a few times from grown men. That's a lesson you DONT want to learn the hard way.

With the advent of reliable +150K motors and very few service tasks required under the hood, and "mysterization" of all mechanical things, what you might think is common knowledge isn't really so common anymore. I work on a eight person team, pretty sure only one of them could reliably identify more than one item under the hood any modern car. Some vehicles, the radiator cap isn't so obvious, in facts it's appearance is deliberately minimized so as not to compete with the overflow tank as the obvious place to service the coolant.
 
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