Cooling system bleeding issue

Hmm never seen that. I have the bleed screw there. Looks like maybe someone replaced it at some point.

I think you can still do a pretty good job of bleeding without it but obviously it would be better if it were there. I wonder if raising the front of the car so the bleed screw on the radiator is higher than the thermostat would help. Probably not as good, but might help.

 

My '75 doesn't have it either. Bleed at the radiator is all you can do. I haven't had any problems not being able to bleed at the thermo neck, though....

 

I didn't think to ask what year. I see now that Buonapart's is a '74 so maybe the bleed screw was a later addition to the housings?

 

No thermostat bleed screw on my '77. Just bleed at radiator, never had a problem.

 

Same here and never had a problem.

 

Remember, the initial bleed is with the engine off and the expansion tank cap off. If the front is much higher than the rear the coolant will just overflow the tank and end up on the driveway. I'd rather not discuss how I know this.

 

Make your own bleeder. What would be so bad about drilling and tapping a hole there? I'd expect the wall thickness to be about 1/8"+......enough to drill and tap in a 1/8" brass pipe threaded plug, which would catch about 3-4 threads. Of course I'd recommend draining down the coolant a few inches, pull off the upper hose and stuff a rag inside to catch the shavings. Have a shop vac standing by too!

Bob

 

Another option is to just (greatly) loosen the hose clamp and then insert a small screw driver, or similar item, between the (unclamped) hose and the housing and over the "ridge" on the housing nipple (just be careful to not damage the ID surface of the hose). This will (temporarily) open an intentional "leak" path between the hose ID and housing nipple OD for bleeding.

 

Is there not a bleed screw on the 1-4 side of the block ?

 

Yes, WAY later in the life cycle of the 308, 1983 or so.

The early cars bleed only at the radiator.

 

My '83 does have the top bleeder. I also modified my brass plug by drilling the double holes (like Verell's) so I do not have to remove it completely to do the bleeding procedure. WAY EASIER and less messy.

 

Just a guess on the year....I have no idea, but there's nothing "missing" off a 308GT4 without one...LOL!

 

My '78 GTS has the bleed screw so maybe mine is not original. Who knows with these cars!!

 

The US SPC illustrations shows that the bleed screw on the thermostat housing was introduced in MY 1978 (but, like wheels, they could be swapped between years after leaving the factory ).

 

That is too low to function as an air bleed Fave. It's only to assist draining the block. I use it to quickly lower the level some minor amount when I need to disconnect any upper hose connections without dumping the whole system.

 

I believe there was a post in the past few years from a guy who invented a bleed screw that had a nipple on it like a brake bleed screw. You could clamp a hose to it and send the excess coolant to a container rather than just the bottom of the car. I have the Verell screw and I have to stuff a rag or towell around the housing to catch as much as possible. This guy's piece was really trick.

 

That sounds even better. But, it won't look "stock" (LOL!)

 

My GT4 was like that until I replaced it with the later housing and modified that further with a brake-bleeder-repairer nipple. The T.Stat housing bleeder does bleed the system much better and with this custom nipple set-up, I don't spill a drop.
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True. I wonder how many concours judges would catch it. Is the OP planning to show at Pebble Beach in the near future?

 

Peter to the rescue... of all nippleless t.stat housings
nice solution !

 

Thanks.

They're available from this Canadian store (although, I'm sure some other places must carry these as well...):

http://www.princessauto.com/workshop/hand-tools/automotive-tools/auto-repair/8237950-bleeder-screw-repair-kit?keyword=brake+bleeder