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No pressure in Coolant hose

95z71performer

By 95z71performer
in Ask A GM Technician

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95z71performer Enthusiast

95z71performer

Posted
Posted

I recently lost pressure in my coolant system on my 1995 5.7 k1500 and I checked for the head gasket being bad and it's not so it there anything else that could cause there to not be any pressure

Wolfmanjohn Enthusiast

Wolfmanjohn

Posted
Posted

Radiator cap; they do wear out and fail. Cheap and easy, too.

95z71performer Enthusiast

95z71performer

Posted
  • Author
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already done

 

what about hoses getting plugged that go to the heater core that's about the only thing I haven't checked yet

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

That wouldn't cause a pressure loss.

 

FWIW, I've got a '86 Grand Marquis I've owned for what will be 11 years this coming January ... 212k miles, and that cooling system hasn't had pressure since '04. It's got a new radiator, hoses, a water pump in '06 ... still no pressure. It runs and doesn't overheat, so I'm not concerned with it. I don't have a trailer hitch on it, so it's not that big of a deal. Probably from the heater core ... but stop leak "fixed" that issue back around '03. Saved me 10 hours of labor ripping the dash out ...

 

Doesn't take much to bleed off pressure. A hose clamp that's a bit loose, bad gaskets, or worn out hoses will do it ... and you'll never see a puddle. They can leak so slowly that it's almost impossible to see, but when you squeeze the upper hose, it's just mush.

 

If it were my truck, I'd only be concerned if I lived down south, or towed alot with it. Up here it's only hot 2 months a year, so it's not a big deal.

 

There's also the possibility of it being a slow head gasket leak ... but lots of times the leak goes both ways, so you'd have combustion gasses in the cooling system. The other way it'll run down the block ... and those can be hard to find as well.

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

Interesting ....

95z71performer Enthusiast

95z71performer

Posted
  • Author
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I'm lost but a friend of mine said to try it and it worked but I'm still not getting the greatest of heat in the truck and this should've fixed it

Jsdirt Senior Enthusiast

Jsdirt

Posted
Posted

Good time of the year to have heat! :cheers:

 

Was 9° here and snowing like hell yesterday. My '89 S10- Blazer with the carbed '00 4.3 was roasting me out of the cab. Heat is a good thing, at least up here .. :thumbs:

txab Senior Enthusiast

txab

Posted
Posted

You had no heat? That's different than having no "pressure". If you had started by saying, "I have no heat coming from the heater core" then you would have had an answer quickly. That would have been to flush the system and core thoroughly and completely.

95z71performer Enthusiast

95z71performer

Posted
  • Author
Posted

No heat and no pressure to start now just no heat

 

And all of this is because of a thermostat getting such and making it overheat

95z71performer Enthusiast

95z71performer

Posted
  • Author
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Yes I did twice because I got a defective one and it wasn't opening fully but we have decided to go on to other issues

 

 

Is it hard to get at the vents inside the dash

gmtech4 Senior Enthusiast

gmtech4

Posted
Posted

Yes I did twice because I got a defective one and it wasn't opening fully but we have decided to go on to other issues

 

 

Is it hard to get at the vents inside the dash,

what does the dash vents comment mean ?,this thread is very hard to follow

 

are you talking air flow thru the HVAC system?

95z71performer Enthusiast

95z71performer

Posted
  • Author
Posted

Not completely sure but its cold on one side and hot on the other and people I've talked to mentioned a flap of done kind in the dash that might not be functioning right

txab Senior Enthusiast

txab

Posted
Posted

Not completely sure but its cold on one side and hot on the other and people I've talked to mentioned a flap of done kind in the dash that might not be functioning right

Are you talking about passenger side vents compared to drivers side vents?

 

You really need to do a better job of explaining your issues in the future. It would help us, help you better

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