merace19
1/2 ton status
As the title says. I looked at a 6.0 in a truck. and after driving it for about 30 minutes in 70 degree temps the coolant system never got pressurized. I could take the cap right off the cooling reservoir.
CK5
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Should there be pressure when hot at the cooling reservoir on 6.0
- Thread starter merace19
- Start date
merace19
1/2 ton status
I was looking at a truck to buy and coolant keep coming out the overflow valve on the reservoir. So we replaced the cap. Now no coolant was coming out of the over flow but there was NO pressure either. I did not know if this was right. I know there is nothing between the reservoir and the radiator to hold back the pressure, because I pressed the upper Rad hose and coolant flowed up into the Reservior.
lectric80
3/4 ton status
Is there a radiator cap on the radiator? If so, then there really shouldn't be any pressure in the bottle. It is really more of an overflow design, where some Chevy cars had pressurized bottles they didn't have a radiator cap. This was because the bottle was under pressure and technically part of the radiator's tank. My Beretta was this way, and it was a total pain to check coolant level, because there was no way to ensure the air was out of the system without getting the car hot. Plus it was a pain when you had to replace a hose or pump, because there is no direct way to fill the radiator.
merace19
1/2 ton status
thanks for responding. If you have a newer 6.0 engine then you would know that the radiator has no cap, its on the reservior. So it must get pressureized correct?
roadnotca
3/4 ton status
I have a 6.0L LQ4, and was wondering how to replace the coolant, as well. Looking at the factory (HELM INC) manual, there are bleed screws at the four corners of the intake valley cover. There's an external pipe that runs side-to-side on the front. I don't have time right now to relate the exact procedure from the manual. I'll transcribe the procedure, and add a photo, tomorrow.
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merace19
1/2 ton status
After running for a while try removing the cap and see if there was pressure in the system.
lectric80
3/4 ton status
On the last one I ran, again not a 6.0 but the same pressurized bottle system, there was pressure after reaching normal operating temps. It wasn't a lot of pressure like you would get when removing a radiator cap. There would be a small hiss of pressure release, but the plastic bottle cannot take a lot of pressure.
merace19
1/2 ton status
That bottle is solid looking. Hell most radiators are plastic now.
roadnotca
3/4 ton status
So I looked at the factory manual. Basically says use the "vac-n-fill" method.
Well that's cute if you have access to a stealer type shop.
Then they have a "static-fill" method. That's for us Guys.
The manual says to back-out the bleed screws, and then fill slowly. I think "fill slowly" means if you have all day. My read is fill it until it stops burping.
What they're saying is to open the bleeds, four of them of which three are a PITA to get to, and also run the engine, and then run it until the thermostat opens. Then wait for the engine to cool and top-off the catch tank. Uh-huh.
I've attached some pics. #1 the PS front bleed (center of pic), #2 the DS front bleed (behind the alt.), #3 target (hose clipped to the fan shroud).
I'm planning to splice a "T" into that return hose. It's above the top of the radiator. I'll park on a slope, with the engine high. I'll use that as the bleed.
The cross-over pipe on the front of the engine (pic #1) measures 1/4", so I'm assuming a barbed "T" at 1/4" will work.
Well that's cute if you have access to a stealer type shop.
Then they have a "static-fill" method. That's for us Guys.
The manual says to back-out the bleed screws, and then fill slowly. I think "fill slowly" means if you have all day. My read is fill it until it stops burping.
What they're saying is to open the bleeds, four of them of which three are a PITA to get to, and also run the engine, and then run it until the thermostat opens. Then wait for the engine to cool and top-off the catch tank. Uh-huh.
I've attached some pics. #1 the PS front bleed (center of pic), #2 the DS front bleed (behind the alt.), #3 target (hose clipped to the fan shroud).
I'm planning to splice a "T" into that return hose. It's above the top of the radiator. I'll park on a slope, with the engine high. I'll use that as the bleed.
The cross-over pipe on the front of the engine (pic #1) measures 1/4", so I'm assuming a barbed "T" at 1/4" will work.
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roadnotca
3/4 ton status
Air bleed.
roadnotca
3/4 ton status
From the book; Start with cold coolant. Unscrew the surge tank cap until hissing starts (if any). When hissing stops, remove the cap. Place an Enviro pan under the lower rad hose. Remove hose at the rad & drain. If you want to drain the block, there is a plug on each side of the block, just above the oil pan towards the front, about where the fuel pump used (on the right) to be on old SBCs. After it's drained, use pipe sealer on the drain plugs. Install the drain plugs at 44 lb ft.
Open the bleeder screws (good luck, see my solution in previous pictures). Oops, reinstall the lower rad hose.
Use a 50/50 mix of DEX-COOL antifreeze (yeah sure), and drinkable water (use distilled or demineralized). Slowly fill the cooling system with 50/50 mixture. They don't say where to fill, but I've read a good tip is to fill at the upper rad hose. I haven't done this yet, so I plan to fill-up the upper rad hose, and fill the surge tank to the "cold line".Close the coolin system (bleeders, hoses & cap).
Start and run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
Allow the engine to idle for 3 minutes.
Shut the engine OFF.
Allow the engine to cool (Baseball game, NASCAR race, etc.).
Top off the coolant as necessary.
Open the bleeder screws (good luck, see my solution in previous pictures). Oops, reinstall the lower rad hose.
Use a 50/50 mix of DEX-COOL antifreeze (yeah sure), and drinkable water (use distilled or demineralized). Slowly fill the cooling system with 50/50 mixture. They don't say where to fill, but I've read a good tip is to fill at the upper rad hose. I haven't done this yet, so I plan to fill-up the upper rad hose, and fill the surge tank to the "cold line".Close the coolin system (bleeders, hoses & cap).
Start and run the engine at 2,000-2,500 RPM until the engine reaches normal operating temperature.
Allow the engine to idle for 3 minutes.
Shut the engine OFF.
Allow the engine to cool (Baseball game, NASCAR race, etc.).
Top off the coolant as necessary.
merace19
1/2 ton status
Well I passed on the truck due to the uncertainty of the pressure on the cap deal. I did not need a headache problem.
