Radiator Question

[Joe F]

As a Fiat owner for almost forty years, I am almost embarrassed to ask this question...

I just installed a re-cored radiator in my X and stopped all the leaks.

Question: On the upper left top of the radiator is the 8mm hex bleed screw, about 1-1/2 inches long. How many turns before it starts to bleed? I've gone almost one full turn and I do not see anything. I would hate to pull it all the way out, it would be a pita to get it back in.

Thanks for any insight.

 

[bbrown]

Joe, in my experience with

bleeding the radiator, I turn it 1/2 to 3/4 turn and fluid (and air!) will bleed through.
Shouldn't take no more than 1 turn unless they changed something on ya.

Hope this helps.

 

[EricH]

It's way more than one turn

Question: On the upper left top of the radiator is the 8mm hex bleed screw, about 1-1/2 inches long. How many turns before it starts to bleed? I've gone almost one full turn and I do not see anything. I would hate to pull it all the way out, it would be a pita to get it back in.

It's way more than one turn to bleed, and it will be loose enough to flow air and water several turns before there is any danger of it dropping out.

If there is a lot of air in the system, it will flow just air for quite a while, so I listen for a faint hissing sound as I slack the screw.

And.... Don't forget to remove the cap on the expansion tank when you're bleeding. You need air to enter the top of the expansion tank to replace whatever comes out through the bleeder, or it won't bleed at all (you may even, god forbid, draw air into the system through the bleeder).

 

[EricH]

Bob's right, I'm right, and Tony's right

... when he says that no two X's are the same!

Half to three quarters of a turn doesn't do it for me on any of four different '74s.

 

[Jim Young]

not sure ,,

I think I use about a turn. I removed mine to put never-seize on the treads. It was easy to put back in. If you do ,,note the angle of the allen key before removal,to get a better idea as to how to replace it ,,also use the long end in the hole to get a better angle view.

 

[eflexter]

I just did mine a week ago.

Mines an '86 though. But it only took 1/2 turn. 1 full turn was more than enough. The seal is the rubber O ring under the head of the screw. At least on my '86.

 

[Joe F]

And.... Don't forget to remove the cap on the expansion tank when you're bleeding. You need air to enter the top of the expansion tank to replace whatever comes out through the bleeder, or it won't bleed at all (you may even, god forbid, draw air into the system through the bleeder).

Very good point, I'll make sure I do.

Thanks all, for your comments

 

[TonyK]

Bleed screw.

The bleed screw is hollow with a hole drill through the centre and another one just below the head of the screw at 90 degees. On the early X rads a fiber washer was used rather than an O ring, over tightening would cause it to fracture and you were now faced with a leak. I hope the rad shop just didn't install a new bolt and O ring, the O ring should be okay, but to expect the air to bleed around the threads may take a while longer than you think. Possibly the hole in the bolt is pluged, but you will have to remove it to find out.


TonyK.

Grimsby Ontario Canada.