professor229

Actually..... I just got back from the store where I bought my flared wrench..... because I went out and looked an it is a flared nut that holds the transmission cooling lines to the radiator... and I also wanted to make sure I bought the right one.... it was 1/2 inch and I also checked for metric, but that 13 mm was a sloppy fit....

Does anyone have any strategy for using the flared nut wrench? or is it one of those, "be careful and go for it" moments..... The only other time I have removed these, is with a vise grip... it always worked and I was lucky.... I don't want to push my luck with this one.... I need this done right because it pulls my fishing boat.... priorities!!!

Also. if it does get screwed up, can a new fitting be used and tied to the older metal transmission line using a neoprene hose patch and clamps?

Thanks for everyone's help...

Gumby22

You could splice in a short piece of rubber line - the trans cooler is low pressure (around 30 psi or less), but to make sure the line stays attached and prevent leaks, I’d recommend flaring each side of the line and position the hose clamps within a 1/4” of the flares.

professor229

First, it has been an amazing morning, and thanks for all those that provided advice.... I have one more request though.....

Back about 20 years ago, I replaced a water pump on a Blazer with a 4.3 and when I was done, it seemed to overheat ..... I remember doing some research and if I remember right, some air gets trapped under the intake manifold which causes the engine to overheat.... If I remember right about the solution, I had to loosen a plug on the intake to let the air escape.... Is that right??? I remember dooing that and the over heating immediately stopped..... Please let me know if this is correct....... and if it is kind of a square bolt I have to loosen... and do I do that when the engine is running or not running? Thanks.....

Now for the day... I ordered a radiator online from Advance Auto with a 25% off coupon and the promise of free delivery TODAY.... at about 8 a.m. a delivery guy shows up with the radiator.... I paid $114 total.... Decided there was no better time so dug in.... took my time.... and got my hands dirty... vowed I would never ever get my hands dirty again but it felt good.... I started in 1968 doing this...... Anyway.... it went well... usual mistakes.... it happens... but overall it went smooth and by 11 a.m. I was doing the test drive... The transmission flare wrench worked flawlessly.... and when I was done and let the truck idle for 20 minutes, there were no leaks... but, I still think there might be some air trapped.... it is NOT overheating but just seems to run a little warmer than usual.... and yes, I took off the cap and pumped the upper hose like crazy for awhile too and watched air bubbles fly out of the radiator ...... Took it for a test drive and everything seems to be fine.... but I still want to know about the bolt on the intake and if I have to remove that to bleed some air that is trapped under the intake......

Suggestion appreciated and welcome......

Little Bear

Never heard of removing a bolt to let the air out. All you have to do is idle the engine with the radiator cap off, let it come up to temp so the thermostat opens. Watch the radiator level, it will drop as the air escapes, add coolant as necessary and once the level stays constant and you can see good flow you should be good to go.

professor229

What you have suggested, I have done... I know that on a Subaru, you have to burp the system by squeezing the upper radiator hose.... I did go back and looked a the intake on this 4.3 and there is a very square headed bolt off to the passenger side that is there for no apparent purpose... it looks like a plug.... I will have to research this some more, but for now, the motor is not over heating but seems to want to fluctuate in temperature more than it did before this intervention.... It may even out with use... I will research this bolt on the intake just a little bit more.... but again... thanks for the information.... and ideas....

Gumby22

If it’s not overheating then you’ll be fine either topping off the coolant in the radiator before each drive or making sure the reservoir is full and letting it fill as the system cools down and draws a vacuum.

The only thing you really need to bleed is the heater core, because that can trap air - with the engine up to temp, set cabin heat and blower to high on the panel setting and let it run for about 5 minutes.

Air will always rise to the highest point, so if you think air is trapped, you can always park on ramps or a slight incline and run the engine with the pressure cap off.

The plug in the manifold you’re looking at could be for bleeding the cooling system or it could be a port for adding a vacuum fitting - you won’t know unless you pull it.