Bleeding the Coolant System

[seintg123]

I'm trying to bleed my coolant system, but having some difficulties. I have a '97 Pathfinder w/3.3L V6 engine. I have my truck jacked up in the front. I've loosened the air relief (bleeder) bolt. I'm filling the rad with coolant, but nothing coming of the bleeder, and the coolant is overflowing out of the rad. What am I doing wrong?????

[ARKQX33V6]

Bleeder removes excess air in the system. Drop anti-freeze by removing lower rad hose and capture fluid, or use c*** at bottom of rad. There is a bleed on side of engine. Plug holes, return rad hose, fill rad leave top bleed open, fill rad to top, run engine to temp, keep filling rad let air out bleed, squeeze

[kkamakasi]

Was that english?

[EsotericImage]

[ARKQX33V6]

Bleeder removes excess air in the system. Drop anti-freeze by removing lower rad hose and capture fluid, or use c*** at bottom of rad. There is a bleed on side of engine. Plug holes, return rad hose, fill rad leave top bleed open, fill rad to top, run engine to temp, keep filling rad let air out bleed, squeeze

I kratiated from skool last night so I do again

Bleeder used is for removing air especially when the cooling system is opened and air is allowed to enter.
When filling with a liquid water/antifreeze, often pockets of air are compressed in the coolant chambers inside the motor.
The compression exerted by the weight of water/ antifreeze puts only a slight compression factor onto these pockets of air.
While filling the radiator, more weight is added to the already compressed air and the already compressed air begins absorption into the coolant mixture.

With a full rad, leaving the top off, and leaving at least 1 of the bleeder holes loose, the hole at top higher than the actual cooling system but joined as part of the system. Pascal's rules soon apply as:

The engine is started and because 75% of the energy is wasted heat, soon the coolant becomes hot, Pascal's rules apply

Expansion
Thermodynamics, heat concentrates, hot moves to less hot, air compresses under heat and pressure.etc etc.

The small amount of air bubbles up to the biggest port of relief, the open rad cap and also to a lesser degree the open bleeder.

When you are satisfied the bigger bubbles have stopped close the rad cap but leave the bleeder open to finalize any smaller bubbles of air. The motor is up to temperature, the coolant is hot the bleeder is closed.

Now you have a closed, tight chamber with hot fluids.

Stop the motor, it cools.

Expansion that took place when hot, reverses and now contraction takes place. The liquid coolant reverses in size.

Attached to this enclosure is an overfill bottle with a cap. An expansion chamber!

Let the motor become cold, check that overfill addendum, there is a normal mark on it and in case there is no identification mark use about 1/3 the volumetric capacity as cold normal maximum fill line.

When cold that expansion chamber should have at least a visual of coolant in it, to the mark but no more. Because when the coolant heats up it expands and that chamber, expansion tank, is the only place within a rigid coolant chamber that can take the expanding heated coolant.

When hot that expansion chamber fills to its max line. So keep the fluids in and out of the expansion chamber at the correct level at hot and at cold temperatures.

Vehicles have drain cocks on their cooling system. With little use these small cocks or valves get stuck. Instead of using these drain cocks a coolant main hose at the lowest part of the system can be easily removed, drain and then re-attached. By using the rad hose lower you can feel, smell, look and examine the condition of the hose. Then replace as needed. The drain c*** is small, the rad hose is big...which do you think will drain faster?

And remember to capture the used coolant mixture, pets will drink it because it is sweet tasting, teen age people have been known to drink it...it is very very dangerous to mammals with eyes and kidneys...it will destroy kidneys and it will make you blind. No repair, no replacement.

It is a hazardous waste and must be collected, safely stored and disposed correctly.

[VG33QX4]

Excessive post

SIMPLE

open cap cold, fill rad with coolant,
fill overflow in between low and high,
start engine with heater on full fan speed vent not recirc
watch temp gauge and coolant level maintain full radiator. jack up front of car slightly so that the radiator is higher than the cylinder heads

AFTER ABOUT 10 minutes of running with the cap off, and constantly filling place cap on rad quickly go drive around and verify no spike in heat and your done. forget the bleed valve, its a waste of time and possible fail point.

the only reason you need to use a bleed valve on any engine is that the cylinder heads are lower than the radiator. this allows air bubbles to form in the block and heads but jack it up and as the water pump pushes the coolant around the bubbles will be sent to the overflow.

[alexf20c]

even easier:

fill up radiator. squeeze hoses. fill up radiator some more.
fill up reservoir to the brim.
check reservoir level next week.

DONE.

[seintg123]

Thank You VG33QX4. I used your method and the car is running great now.