"burping" The Cooling System / Bleeding Air / Weak Heater

chipjumper · January 4, 2008

I changed the T-stat in my truck about a week ago. I noticed that the heat isn't as hot as my brothers identical truck.

Could it be possible that I didn't "burp" the truck correctly after I filled it back up with coolant? Engine temp is fine.

What is the proper technique for these specific trucks? (4.8, 5.3, 6.0) I can't find an air bleed hole like on my Impala.

Do I just let it run with the coolant resevoir cap off for a while with the heat on full blast?

redvett · January 4, 2008

Did you check in a pot on the stove and check the opening temp? Should be opening at 195F. Also if its a cheap stat its going to be very marginal on where it will open.

Since your truck has a coolant recovery system as part of the entire cooling system there is no burping needed.

chipjumper · January 5, 2008

Did you check in a pot on the stove and check the opening temp? Should be opening at 195F. Also if its a cheap stat its going to be very marginal on where it will open.
Since your truck has a coolant recovery system as part of the entire cooling system there is no burping needed.

Interesting; no i didn't do a stove check. This is an OEM t-stat. The one it replaced was bad --- only opened after i hit it with a blow torch.

LAGA · January 5, 2008

I can`t help with the bleeding, but in the future. Drill a 1/32" hole in the body of the new thermostat. This will allow any trapped air to escape on it`s own.

Zembonez · January 5, 2008

I can`t help with the bleeding, but in the future. Drill a 1/32" hole in the body of the new thermostat. This will allow any trapped air to escape on it`s own.

No offense - BUT - I think this is risky advise at best. I would never alter the only item responsible for maintaining the temperature of my engine's coolant.

The system does require burping. Here is a link to the GM recommended procedure. (given to me by another GM-Trucks.com member)

BURPING THE SYSTEM

LAGA · January 5, 2008

I can`t help with the bleeding, but in the future. Drill a 1/32" hole in the body of the new thermostat. This will allow any trapped air to escape on it`s own.

No offense - BUT - I think this is risky advise at best. I would never alter the only item responsible for maintaining the temperature of my engine's coolant.

The system does require burping. Here is a link to the GM recommended procedure. (given to me by another GM-Trucks.com member)

BURPING THE SYSTEM

No offense taken, however, drilling such a small hole hole in the side of the body of the thermostat has no measurable effect on the performance of the stat. Even in cold weather the stat opens in about 5 minutes of driving and the small amount of coolant that would sneak through before that happens is minute. I learned this trick years ago and have done it many times with no ill effects.

Zembonez · January 5, 2008

No offense taken, however, drilling such a small hole hole in the side of the body of the thermostat has no measurable effect on the performance of the stat. Even in cold weather the stat opens in about 5 minutes of driving and the small amount of coolant that would sneak through before that happens is minute. I learned this trick years ago and have done it many times with no ill effects.

It's quite possible you are right. I can't see what harm such a small hole would do. It would take a lot more hole size than that to pass much coolant. I must admit I've never heard of doing it... but I learned a long time ago that you can never know it all.

chipjumper · January 7, 2008

Hey thanks guys for the advice. I'm so busy with everything in life that when I made this post a few days ago I didn't realize that it was 5 degrees outside. I guess I shouldn't have whined so much. Hard to complain now though since its 55 degrees and rising at 11PM!

minibike132 · January 7, 2008

Hey thanks guys for the advice. I'm so busy with everything in life that when I made this post a few days ago I didn't realize that it was 5 degrees outside. I guess I shouldn't have whined so much. Hard to complain now though since its 55 degrees and rising at 11PM!

You must be somewhere near Chicago. I looked and looked for an affordable vacuum filler for the home mechanic. I bought mine 8 years ago for $25 and it has been a great investment. At $145 I would still buy this one but you would have to do alot of cooling system service to justify that, maybe someone can come up with a cheaper alternative somewhere and post it. Basically you put the big plug on the filler(radiator neck or filler bottle per application) you run compressed air through the inlet and this creates a vacuum in the entire coolant system leaving no air pockets. Then stick the filler hose in more than enough coolant(my bucket stays at 4 gallons) and when you open the valve the coolant takes the place of the vacuum. This thing has never let me down I have never had an air pocket since I got it and I don't even bother warming a vehicle up after service to make sure there isn't one. If anyone can find one cheap let us know.

chipjumper · January 7, 2008

That tool looks neat. Looks like my brother will be getting that for his upcoming birthday. Thanks!

Mikeee · January 16, 2008

Just finished replacing the water pump on my '03 Savana with the 5.3.

Per the service manual (sorta):

Pull of the purge line from the radiator.

That is the smaller hose that comes from the air intake warming flange and enters the radiator just under the overflow tank connection.

Disconnect the upper radiator hose from the radiator.

Pour in 50/50 DEXcrap into that hose until the fluid escapes from the disconnected purge hose.

Reconnect the upper hose.

Reconnect the purge hose.

Add 50/50 DEXcrap to the overflow tank.

Monitor the overflow tank for fluid level during the next few cold/hot/cold cycles.

minibike132 · January 16, 2008

Just finished replacing the water pump on my '03 Savana with the 5.3.

Per the service manual (sorta):

Pull of the purge line from the radiator.

That is the smaller hose that comes from the air intake warming flange and enters the radiator just under the overflow tank connection.

Disconnect the upper radiator hose from the radiator.

Pour in 50/50 DEXcrap into that hose until the fluid escapes from the disconnected purge hose.

Reconnect the upper hose.

Reconnect the purge hose.

Add 50/50 DEXcrap to the overflow tank.

Monitor the overflow tank for fluid level during the next few cold/hot/cold cycles.

Per what service manual?

minibike132 · January 16, 2008

Just finished replacing the water pump on my '03 Savana with the 5.3.

Per the service manual (sorta):

Pull of the purge line from the radiator.

That is the smaller hose that comes from the air intake warming flange and enters the radiator just under the overflow tank connection.

Disconnect the upper radiator hose from the radiator.

Pour in 50/50 DEXcrap into that hose until the fluid escapes from the disconnected purge hose.

Reconnect the upper hose.

Reconnect the purge hose.

Add 50/50 DEXcrap to the overflow tank.

Monitor the overflow tank for fluid level during the next few cold/hot/cold cycles.

Per what service manual?

Sorry my bad that is per the 03 manual. There is a manditory tool that is something like the tools I posted that GM made us put in the tool room because this procedure was unreliable.

Geno · January 16, 2008

Just finished replacing the water pump on my '03 Savana with the 5.3.

Per the service manual (sorta):

Pull of the purge line from the radiator.

That is the smaller hose that comes from the air intake warming flange and enters the radiator just under the overflow tank connection.

Disconnect the upper radiator hose from the radiator.

Pour in 50/50 DEXcrap into that hose until the fluid escapes from the disconnected purge hose.

Reconnect the upper hose.

Reconnect the purge hose.

Add 50/50 DEXcrap to the overflow tank.

Monitor the overflow tank for fluid level during the next few cold/hot/cold cycles.

Per what service manual?

Sorry my bad that is per the 03 manual. There is a manditory tool that is something like the tools I posted that GM made us put in the tool room because this procedure was unreliable.

I hope this helps. This ino was obtained from "ALL DATA ONLINE".

Notice:</B>When adding coolant, use DEX-COOL coolant. If silicated coolant is added to the system, premature engine, heater core or radiator corrosion may result. In addition, the engine coolant will require change sooner at 50 000 km (30,000 mi) or 24 months.

Close the radiator drain cock;.
Fill the system through the surge tank opening.
Pre-mix a 50 to 60 percent solution of DEX-COOL and clean. drinkable water.
Slowly add the pre-mixed solution to the surge tank until the level is slightly above the surge tank split line.
Start the engine.
Idle the engine for 1 minute.
Loosely install the surge tank cap. Do not allow the system to build up pressure.
Cycle the engine from idle to 3000 RPM in 30 second intervals until the engine coolant reaches 99°C (210°F) and the thermostat opens.
Shut off the engine.
Refer to step 3 in order to remove the surge tank cap.
Start the engine.
Idle the engine for 1 minute. Fill the surge tank to 1/2 inch above the COLD FULL mark on the surge tank.
Install the radiator surge tank cap.
Cycle the RPM. Idle the engine to 3000 in 30 second intervals until the engine coolant reaches 99°C (210°F).
Shut off the engine.
Top off the coolant, as necessary, to 1/2 inch above FULL COLD mark on the surge tank.
Rinse away any excess coolant from the engine and the compartment.
Inspect the concentration of the coolant.