Bleed/Burp radiator

[chucksnee]

Hello all,

 

I have a 2007 GMC with a 4.8l engine. I just changed my radiator, filled it with fluid, did everything that I was supposed to do, except now I have no hot air?

 

I have tried burping/bleeding the system, is there anything else I can do? Do I need to burp/bleed the system more?

 

Thanks in advance,

 

Chuck,

[txab]

Have you tried this procedure posted on this site?

 

 

Basic procedure:

 

 

 

1) Get a jug of DEXCOOL.


2) Park on level ground.


3) The engine needs to be cool, or just slightly warm is fine too.


4) Add fluid in the surge tank until the level is slightly above the split line on the tank (an inch or so).


5) Put cap back on loosely, don't allow it to build pressure.


6) Start engine and let it idle for a minute.


7) Cycle the engine from idle to 3000rpm in 30-second intervals until

the engine coolant reaches operating temp and the thermostat opens.


8) Shut off engine and remove the cap.


9) Start engine and let it idle for a minute. Fill the tank to 1/2 inch

above the "Cold Full" mark on the tank & put cap back on loosely.


10) Cycle the engine like before and wait for the thermostat to open again, then shut off the engine.


11) Put more fluid in if necessary, the fluid should be a half-inch or so above the Cold Full mark.

[chucksnee]

Have you tried this procedure posted on this site?

 

 

Basic procedure:

 

 

 

 

 

 

 

1) Get a jug of DEXCOOL.

 

 

2) Park on level ground.

 

 

3) The engine needs to be cool, or just slightly warm is fine too.

 

 

4) Add fluid in the surge tank until the level is slightly above the split line on the tank (an inch or so).

 

 

5) Put cap back on loosely, don't allow it to build pressure.

 

 

6) Start engine and let it idle for a minute.

 

 

7) Cycle the engine from idle to 3000rpm in 30-second intervals until

 

the engine coolant reaches operating temp and the thermostat opens.

 

 

8) Shut off engine and remove the cap.

 

 

9) Start engine and let it idle for a minute. Fill the tank to 1/2 inch

 

above the "Cold Full" mark on the tank & put cap back on loosely.

 

 

10) Cycle the engine like before and wait for the thermostat to open again, then shut off the engine.

 

 

11) Put more fluid in if necessary, the fluid should be a half-inch or so above the Cold Full mark.

Thanks Txab, I searched for this, before I added this thread, maybe I did not search the correct words. Anyway, I did not do those exact steps, but were very close, about the only thing I need to try now is leavnig the cap loose while the engine is heating up.

 

Thanks again, I'll just keep trying to burp/bleed the engine.

[Wolfmanjohn]

If you have the luxury of living in a hilly neighborhood, run it around in first gear/~2500 rpm. Really sped up the burping process in my son's '07 'Hoe with rear ac/heat since everything was rockin' and rollin' from front to rear, and never got more than 3 blocks from the house.

[chucksnee]

Update:

 

O.K., so, since the last time I was here, I could still not get the heater to work after doing all the burping instrcutions given here on this website.

 

So, I started over, I drained all the coolant, this time removed the top and the bottom hoses and flushed the engine until clear water ran. Even though the radiator was new I flushed all the dexcool out of it until it ran clear. This time I also changed the T-stat ($30, damn near fell over) I also changed the radiator hoses this time (just went over 100,000 miles).

 

Anyway, I cut the old radiator hoses to use as a fill for the top radiator, poured dexcool until it ran out the bottom, then quickly threw the hose on the bottom and secured the hose to the radiator. Then I put the t-stat housing on (without gasket seal, this maybe where I screwed up) and fully tightened the bottom radiator hose. Put the new radiator hose on top and secured.

 

After ensuring everything was tight, I filled the fluid tank till it was full, I had my wife start the truck so I could have fluid ready to pour into tank as the engine got warmer, the tank always had fluid in it, even when the t-stat opened, I made sure of this. After doing all this I followed the instructions above and still no heat, it's just as cold as my A/C, with the heat turned on.

 

Could the T-stat housing, not having gasket seal be pulling in enough air to cause me not to have heat?

 

Guess I'll find out....

 

Any other suggestions?

 

 

[music]

Are you sure that the heat/air damper is engaging? I can't imagine it blowing cold air w/ the temp control on hot (and damper engaged), whether air is in the coolant line or not.

[chucksnee]

Are you sure that the heat/air damper is engaging? I can't imagine it blowing cold air w/ the temp control on hot (and damper engaged), whether air is in the coolant line or not.

Everything worked fine before this, Is there a way to check this?

 

I'm about to go remove the t-stat and put some sealant around it, just to be sure.

[chucksnee]

O.K. so, here is what just hppened, I took the t-stat housing off, cleaned it all up, put blue sealant around the housing, reinstalled everything, filled up the surge tank, wife started the truck, I made sure the surge tank never went empty while ideling @3000 ish.....back and forth until the truck would take no more fluid.

 

Turned the heat on, while ideling, and back to noraml, I have heat, tried the different ranges, working good, while at idle. So, I spray everyting off, get in the truck, drive it to town, (5miles) and no heat, while driving, I turn the heater off, no AC, drive it back home, and while I'm backing into the garage, I notice puddels of water making a line, now the surge tank is overflowing....

 

Does anyone have a clue? I guess I'm going to take it to the shop....damn, all this over changing a radiator....

[music]

The info you're giving is incomplete to diagnose, imho. My first step would have been to verify that the heater damper is working. The fact that you now have no A/C or heat is consistent with the damper not moving when the temp control is turned, but that's a total guess. As for the thermostat, etc., if the temp gauge is moving up to where it's supposed to (210F), then the coolant loop is complete. You say it was all working before, but is it possible that a connector was left unplugged somewhere in the system? I just finished swapping a radiator in a Toyota Sienna, and there were a bunch of things I had to disconnect/reconnect under the hood for clearance.

 

It could literally be something as simple as a blown fuse, but we have no diagnostic info to go by. You should probably take it to a GM shop and let someone look it over at this point, rather than beating your head against a wall

[chucksnee]

O.K., so it is fixed, and I really fixed it in the 30 June 2013 posting. So let me explain, everything I said was correct in that posting, except when I put the manifold cover on, I pinched one of the heater lines going into the fire wall, between the plastic and the manifold itself, this caused the the over heating. The problem was I did not see that hose under the cover and still took it to the dealer. Anyway, $90 an it is fixed.