Best way to burp coolant system?

[johnyQ]

Just had to change a coolant hose out, and I am getting a mild overheating issue. Obviously I trapped some air in there, whats the best way to get it out?

So far all I did was run it w/o the cap on, and massaged the hose.

(I know this is a dumb questions and I apologize)

[Def]

There's a 10mm bolt in the water outlet neck(it's right by the CAS). Just take it out and run the engine at idle. All air will be pushed out in short order, and you'll make a nice coolant puddle in the process.

[SpeedRacer1]

What you can also do is run the car until you see the needle spike. Then pull over, using a few layers of cotton towels, open the radiator cap. Whatevers left should gush out in extremely hot steam form, then when you see coolant close the cap. Later on when the car is cool open the radiator cap and fill it to the top.

[Def]

No offense, but that sounds like a really good way to get 3rd degree burns over half your body.

The bleed screw is there for a reason - use it. It's probably the easiest thing you'll ever do to your car. I've flushed the radiator in my SR about 5 times now, takes about 10 seconds to bleed...

[rudee023]

When bleeding make sure to move the heater to full hot.

[180fan]

also after the coolant comes out the bleeder hole, plug it, keep filling, and squeeze your radiator hoses.

[SpeedRacer1]

Radiator cap works when the bleeder screw doesnt get all the air out of the system. Only an idiot would burn himself, you use plenty of protection.

[S13240]

Radiator cap works when the bleeder screw doesnt get all the air out of the system. Only an idiot would burn himself, you use plenty of protection.

I'm not an idiot, I just don't have enough balls to do that with the radiator cap :icesangel

[Def]

Radiator cap works when the bleeder screw doesnt get all the air out of the system. Only an idiot would burn himself, you use plenty of protection.

The cooling system will be under EXTREME pressure when it is hot, especially overheating like you are stating. Hot coolant spraying out the cap just sounds like bad news.

Also, I don't believe we have to move the heater to the full hot position with our cars - at least that's what it says in the S14 SR FSM. I believe the heater is always circulating coolant, but a vent flap lets air go through it or not.

[VitaminT]

I know on the S13 there is a flap on one of the heater core inlet/outlet pipes. It appears to cut off circulation, but it has been a long time since I looked at the cables and stuff for it. Replacing a heater core was not one of my fondest memories.

BTW...I think on most cars they tell you to fill the radiator (I usually squeeze the hose to get the big bubbles). Then set the radiator cap to 1 click so that it is on, but dosen't build too much pressure. Then run the car down the road and back to get it to normal operating temp. Finally open the bleed screw untill solid fluid comes out. Usually when I do this I get a pressurized jet of air out the bleeder. Then make sure the radiator is topped off and close the cap all the way.

[SpeedRacer1]

The cooling system will be under EXTREME pressure when it is hot, especially overheating like you are stating. Hot coolant spraying out the cap just sounds like bad news.

The coolant system isnt under extreme pressure. Its just under slight pressure, you can tell how much by looking at your radiator cap. The reason the coolant gushes out when the engine is warmed up is because when you open the radiator cap, the coolant ceases to stay in fluid form and immediately boils because of the pressure change.

But smother it with plenty of towels and you shouldnt have a problem.

Its almost unrealistic to bleed the system of air on the first try. Keep checking under the radiator cap when its cold to see if the level is low.

I think most people screw up burping the system using the bleeder valve because they open it, then cap it off as soon as the see the slightest bit of coolant come out. It should be a steady stream of coolant coming out.

[Def]

Uhhh - if the system is boiling hot, then I think the stock cap is about 12 psi and the Z32 cap is about 18 psi. Not what I'd call slight when an air pocket rushes out and shoots you with hot coolant.

The coolant suddenly boiling if it was over 212 *F would also be a nice touch to add.

I've bleed my cooling system tons of times with no problem whatsoever. Just keep adding water, occasionally squeezing the hoses, then crack the bleeder and it probably doesn't take more than a few seconds to get just coolant coming out.

[johnyQ]

excellent posts, thanks for the help!

[nismodave]

Man...........Ive installed 3 srs and I just wait for the car to be cool...........take the cap off............then run it with the heater on blowing Hi.............Run it for a while.............Never had a poblem

Oh......buy a Dual FAL fan.........I run a stock radiator with a heavily modified Sr20det.......and the car runs perfectly cool.......or as cool as the hot *** Srs run.......LOL