Closed system radiator

[specialkeay]

How do I bleed the air on a closed system radiator. I have an 89 4.0.

[Mongo]

pull the upper radiator hose off and burp it by squeezing the lower one. Do it slowly as you will force some of it out of the block. top it off, reconnect and continue burping it by the upper hose. Run it up to temperature, and it should all be good.

[TrailReadyMJ]

This is basically the procedure stated in the FSM according to my memory...

 

 

1) Park on a hill, facing downhill. It has to be steep enough that the back of the engine is higher than the front.

2) LET IT COOL DOWN! Then locate the coolant temp sensor on the back of the head. This sensor will have one wire attached (brown IIRC), and threads into the top of the head toward the drivers side.

3) Top off the tank/pressure bottle and keep cap loose. You will want to be able to tighten it down quick though, read below.

4) SLOWLY Remove the sensor from the head using a 1/2" socket. An extension and swivel can be handy here too. Be very careful to not lose the sensor, and keep it ready to put back in real quick!

5) Once coolant flows from the sensor location, re-install the sensor. (this will/should only take a second!)

NOTE: the sensor can sometimes be tricky to get started, especially when plugging a hole where coolant is flowing out. You can slow the flow of coolant by tightening the pressure cap, just make sure it doesn't stop and suck air back in before the sensor is tightened down.

Make sure your pressure tank remains full at all times! The last thing you want to do is suck air back in. Think of it like bleeding brakes.

[mkbruin]

This is basically the procedure stated in the FSM according to my memory...

 

 

1) Park on a hill, facing downhill. It has to be steep enough that the back of the engine is higher than the front.

2) LET IT COOL DOWN! Then locate the coolant temp sensor on the back of the head. This sensor will have one wire attached (brown IIRC), and threads into the top of the head toward the drivers side.

3) Top off the tank/pressure bottle and keep cap loose. You will want to be able to tighten it down quick though, read below.

4) SLOWLY Remove the sensor from the head using a 1/2" socket. An extension and swivel can be handy here too. Be very careful to not lose the sensor, and keep it ready to put back in real quick!

5) Once coolant flows from the sensor location, re-install the sensor. (this will/should only take a second!)

NOTE: the sensor can sometimes be tricky to get started, especially when plugging a hole where coolant is flowing out. You can slow the flow of coolant by tightening the pressure cap, just make sure it doesn't stop and suck air back in before the sensor is tightened down.

Make sure your pressure tank remains full at all times! The last thing you want to do is suck air back in. Think of it like bleeding brakes.

 

:agree:

 

Temp sensor: