Burping the LS1 cooling system (questions)

[joecar]

I found I could burp the LS1 cooling system better/easier/quicker by connecting a 5 ft (or so) length clear tube to the front cross-over pipe, the other end of the tube going into a bucket/bottle on the ground;

I can see air/vapour coming out, and when I see only coolant then I know I'm done, remove the clear tube and connect the TB[-bypass] hose, top up radiator and install cap.

Now, how do I prevent a whole big glop of coolant from flopping out the radiator neck just before the coolant level goes down (...it's just like it threw up at me...)...?

I even tried to allow for this by filling not-so-high, but the level just kept coming up and then threw up everywhere;

should I have put the cap on before it reached the top of the radiator neck (but then I would still have to add coolant)...?

The Service Manual says to open the bleeder on the thermostat housing.... that seems to be carry-on from when the TS was on top; I don't see a bleeder on mine (and it wouldn't work because the TS is down low);

Yeh, I had to replace the heater core, it was fogging my windscreen/windshield with coolant.

[TAQuickness]

got pics of this contraption?

[joecar]

I don't have a pic (I'm still in the dark ages)...

it's a 5ft length of clear 1/4" vinyl tube;
end A goes on the cross-over tube outlet (that would normally goto the TB);
end B goes into a 1 gallon clear plastic water bottle;

this minimizes the amount of coolant that will get spilled on the belt/pulleys while you're trying to burp the air out of the block/heads;

ha, I should get a patent on this.

I'll see if I can get a pic.

[Brains]

Hmm.. I always just fire up the motor and let it run with the radiator full, and then fill it back up when the t-stat opens. Never had an issue, very little to zero spilled coolant.

[joecar]

Hmm.. I always just fire up the motor and let it run with the radiator full, and then fill it back up when the t-stat opens. Never had an issue, very little to zero spilled coolant.

Hmmm... that's exactly what I started doing...

I filled the radiator all the way, started engine, let it idle...
pretty soon the temp gauge shot up >200+ and climbing [alarmingly] fast, fans turned at high speed, TS was cold (as was lower hose)...

so I pried the TB bypass hose off the cross-over tube (using a long screwdriver) and a bunch of hot air shot out (I was expecting it) and then some coolant/air shot out (all over the place ) so I put the clear tube on and into the 1 gallon bottle... and temp gauge quickly started to drop down <200 (phew...)...

then when TS opened, coolant threw up out of radiator neck (why...?);

it seems with TB bypass hose on, the air can't push out because the level in the radiator is covering the bypass inlet in the neck; if I allow room, then pretty soon the coolant level starts rising then overflows out of the neck (why...?);

I remember this happening to me 2.5 years ago when I replaced the water pump and TS, and I had to burp it the same way;

do I need to drill a hole in the TS...?

BTW: car drives fine, drove it to/from work this week with no drama, temp is good.

Edit: TS is 180, fan turn on/off temps are lo=196/191 hi=207/196; car runs 190 at light load.

[wait4me]

Usually all i do to burp the system is i jack up the front corner of the car and all the air just goes to the top corner, then i just keep filling till it is full, then put the car down and go..

[joecar]

Ok, I'll try that next time.

So any ideas why it vomits coolant when the TS opens...?

[wait4me]

Because hotter watter is larger. It expands, so, when the ts is closed, the engine is heating up that water very fast, It expands, then when it is opened it is forced out into the radiator where it also makes that water expand as it heats up the fresh uncooled water.

[joecar]

Is there a way I can prevent it from vomiting...?

Edit: oh, I see, jack up the front of the car.

[FFP]

I know this is a old post but if you remove the upper hose from the rad and fill the motor first then but the hose back on and fill the rest of the rad it will make sure that there is coolent behind the thermostat and you wont have that problem.


Bill
www.forcefedperformance.com