Upper Radiator Hose has no pressure

[Frankenchevy]

If the engine in your truck is in stock form, Napa or a similar store should have the correct pre bent upper and lower radiator hoses listed. You can always pull the old ones before going to compare them against. Gates is a good brand to get. Also, I’d get actual heater core hose. It’s 3/4 and 5/8 iirc and you’ll want roughly 4-5’ of each. Don’t forget some fresh hose clamps.

 

[AuroraGirl]

I replaced my lower hose a few years ago with a brand from auto value. No idea the number. It was their inhouse brand, parts master I believe. it was searched for a 1980 GMC K2500 with a 5.7 (350) gas. It works fine.

 

[AuroraGirl]

Silly question, did you crank the heater on high and run the air out of those lines as well? BTW, I would replace the heater hoses too. The one on the w/p is looking a little peeked and tired.

Haha, thats MY truck not the OP. lol. I know my heater hoses are bad. I need to replace them.. atm its not high priority because of the little use. But Its coming. And its an old photo, but they are still there. I periodically cut offf the end and reclamp. It keeps peeking.

 

[MikeB]

What do you expect to feel there? Even with coolant running through the hose, it won't feel like it's pressurized. Does it get hot? Have you tried removing it from the radiator to see if coolant shoots out? Does your lower hose collapse when the engine is running?

On another note, I have seen coolant temps stay well below 180 on 30-40 degree days, even after a driving the vehicle for a few miles. But I doubt it's been that cold where you are.

 

[MikeB]

I'll probably run to the hardware store and get tubing for the heater hoses.

Hardware store? Don't get tubing, get heater hose at an auto parts store!

 

[Cuba]

I'm working on fixing my 81 C10 I bought, and I'm at the point of engine cooling. I went ahead and threw a new thermostat on (AcDelco 195) and radiator cap (AcDelco), And I drained the radiator, filled with water, and after getting up to temp, still no pressure in upper radiator hose. Temp gauge shows a little before middle point (don't really know how accurate it is). What do you guys think?

I' ve read this entire thread....
1st. Hose will not pressurize unless the radiator cap is on. Cap needs to be able to hold up 15-16psi in this system in order to cool properly. The higher pressures in the system are what raises the boiling level. So instead of boiling over at the typical 212*F, It's now up to 240*F or more.

2nd. Lack of driving it may not allow the vehicle to heat up all the way. Sometimes you need to drive it around your neighborhood a few laps to help it along. It all depends on ambient temps. Below 70*F, you'll find it hard to reach temp in a reasonable time just sitting idle.

3rd to properly "burp" a cooling system, be sure to turn the heat on. This will provide some clues to how the cooling system is operating. Air must be blowing hot... which in order for it to blow hot, coolant must be circulating well. So if air blows hot, this will rule out air pockets and function of water pump.

4th. Bad hoses won't prevent a hose from builiding up pressure, unless it's leaking.

 

[olnick]

Check your new cap! Some of the replacements are designed to allow the coolant to flow from the radiator back to the recovery tank. This ensures the radiator is always full . IF the engine gets HOT and the coolant begaing to boil, the cap WILL HOLD pressure as expected! I first ran into these caps about 30 years ago and thought the same as you about the house not being hard. I currently have one of those caps on my 78. To check the style of cap look at the underside, the center ring (VACUUM VALVE) will be LOOSE and Not held up with ANYY spring tension!
Just run and enjoy your truck

Olnick

 

[ceejay]

Sorry I haven't gotten back to you guys. I replaced the heater hose tubing with actual heater hose. Sorry that might of got misinterpreted when I said I was going to the hardware store. I replaced upper and lower radiator hose. I burped the system for about 30 min till no bubbles or anything. Drove it around the block a few times and it seems good. I won't know for sure until I drive it on the street a while I think. The truck is technically not legal to drive right now since I have it black tagged, but once I finish a few other things, I'm gonna go tag it and drive it and see what happens then. Thanks everybody!

Sent from my HD1907 using Tapatalk

 

[Cuba]

Yeah, I get not driving it on main rds. The update is greatly appreciated!