Well as some of you may know we just got N/A Madness running again. The only way to bleed the coolant on an ld9 is to take the over flow cap off and let the air bubbles come out as we run it and keep filling as the coolant level goes down correct. or is there another method? better way or some thing to get all the air out?

The cooling system was completely dry after the rebuild.

If there's no bleed screw (which would be located within the general vicinity of the thermostat housing, for the most part), then yes, your method is correct. Keep the recovery tank cover off, run the vehicle, and continually add coolant as needed. A couple things we keep an eye on for vehicles with no bleed are:

1) the temperature gauge - if you've got really bad air lock in the system, it will eventually start to overheat
2) the heater - crank it to full blast, if the rad hoses are getting extremely hot but there's no heat coming through the vents, it's usually a decent indication of either air lock, or a faulty thermostat, but if there's nothing but a constant solid blast of heat, chances are you're good to go

I don't have my car in front of me right now (it's got a dead tranny 14 hours away from home), but I believe the recovery tank is higher than the radiator. In theory, any possible air that may be trapped in these systems will rise to the highest point, that being the recovery tank. So, as long as you have run the vehicle at operating temperature for a fair length of time and the coolant level has stayed constant, again, you should be good to go.

In any case, it's always a good idea to check the level before and after your first couple of drives post-coolant flush/fill.

[In theory, any possible air that may be trapped in these systems will rise to the highest point]

Just to add to the sound advice you have so far, I read somewhere that a shop owner always bleeds the air out with the car on ramps at the front, this really makes the recovery tank the highest point.

I tried it on my '93 after a h/gasket change and only needed that one bleed.


Alont

alont wrote:[In theory, any possible air that may be trapped in these systems will rise to the highest point]

Just to add to the sound advice you have so far, I read somewhere that a shop owner always bleeds the air out with the car on ramps at the front, this really makes the recovery tank the highest point.

I tried it on my '93 after a h/gasket change and only needed that one bleed.


Alont

Wouldn't that put the rad higher than the tank?

On my cars and liquid cooled ATV's I've always just driven it a little bit then add to the overflow tank to the full mark. Keep doing this until the radiator quits sucking from the overflow tank.

Rob





Sold 2/2/05

I have never had a problem with air pockets on a J. I always start them with the cap off and let the thermostat open and fill some ore. At that time I would put the cap on. After letting the car cool check the coolant level again.



FU Tuning