Early cars just had overflow...not good since there was always air in radiator for expansion. Later cars have recovery so radiator stays full and when motor cools coolant can go back where it came from. Caps are different....you have to use later cap in order to get the coolant to return. Basically a 2 way cap rather than just puke.... Does that help?
Why do you need a special cap? I thought the philosophy was under heat and pressure the fluid goes out the top radiator nipple through the hose into the bottom of overflow tank and as radiator cools and pressure reverses the fluid gets sucked back into radiator. But that doesn't mean I understand how any of this stuff works that is just what I thought happened.
So they have different radiator caps???? Since when?? Never heard of any such thing! Please explain this to us, cause inquiry minds want to know! Keith
^^^^^^^^^^^^^^ Ditto^^^^^^^^^^^^ I put a apple juice jug in my 67 for a coolant recovery tank.... work fine... My Rad is a GS 400 4 core not stock. It doesn't have the factory full line on it, so this was my way to make sure its full. I just keep a eye on the AJ bottle no reason to pop the cap...
A cap for a recovery system has two rubber seals: on the face of the main valve, which seals against the lower inner diameter of the radiator neck (all caps have this seal), and a larger seal, just under the cap’s underside, which seals against the outer upper diameter of the radiator neck. This forces overflow coolant through the overflow tube rather than gushing past the cap, and when the system cools down and coolant volume in the radiator decreases, the suction is channeled to the overflow tube, which instead of sucking air draws coolant from the reserve tank back into the radiator.
MANY caps you buy today have BOTH seals on them. Maybe reason some have had no problems. They were just not aware of the double seals.
thanks!!!!!!!! does not answer my ?changing to a billet alm tank. summit offers recovery and exp.tank! which should I get to replace stock unit?thanks Kenny!
Recovery tank. We don't need an expansion tank. http://blog.cantonracingproducts.com/blog/setting_up_your_cooling_system_expansion_vs_recovery
Thanks for the link. I learned something today. The "expansion tank" was called a "Surge Tank" in the bus business.
Looking for a home-made cheap recovery tank/bottle any clue ? For a 68 Skylark w/stock 350. Thank you
Yes, I use an old water bottle about the same size Tom suggested above. It fits snugly in between the radiator and (what's left) the core support. Make sure the hose from the overflow is long enough to get down into the fluid, or you won't get any return. This is obvious, but I can't help but say it.
Dorman - https://www.v8buick.com/index.php?t...swap-into-66-67-skylarks.375018/#post-3273764 cheap and looks decent
I recently bought mine a AutoZone, they were a few dollars cheaper than the other big box auto parts stores that I looked at. Thanks,
When I put a recovery bottle into my '68 'Camino, I grabbed a mid-70s Nova recovery bottle from the Treasure Yard, and hid it behind the battery. Be sure to use a rad cap suited to use with a recovery bottle. The non-recovery-bottle rad caps don't have the secondary seal to prevent air entry into the rad.
This Dorman one is cheap and easy to find a location for. It should work well for you. Like $10 for one. Greg
I have a 151 bottle in my car and my son has a Crown Royal bottle. Use what ever you would like just run the hose to the bottom.