AST overflow connected to nothing!
03-20-20, 09:04 PM
#1
Supermade
Thread Starter
AST overflow connected to nothing!
After I got done taking care of my heater hose that was cracked, I saw some coolant leaking. After inspecting where the leak was coming from, I realized that the top overflow hose on the AST was connected to nothing and was just spilling out on the floor.
Is this normal? I just recently got the FD. I believe the overflow tank is still there but nothing is connected to it. But I'll check if there are lines running to it. I'll try to get some pics up.
Is this normal? I just recently got the FD. I believe the overflow tank is still there but nothing is connected to it. But I'll check if there are lines running to it. I'll try to get some pics up.
03-21-20, 05:51 AM
#3
No, dumping overflow coolant straight to the ground hasn’t been “normal” on cars for over 60 years.
The top “overflow” pressure relief hose should go to your overflow tank.
I don’t disagree with deleting it, especially if you have a stock plastic AST but it is optional with a metal ast. And search for the proper way to delete it. Banzai’s billet filler necks are really nice if you chose that route.
http://www.banzai-racing.com/store/93%2B_rx-7_AST.html
The top “overflow” pressure relief hose should go to your overflow tank.
I don’t disagree with deleting it, especially if you have a stock plastic AST but it is optional with a metal ast. And search for the proper way to delete it. Banzai’s billet filler necks are really nice if you chose that route.
http://www.banzai-racing.com/store/93%2B_rx-7_AST.html
Last edited by Sgtblue; 03-21-20 at 05:56 AM.
03-21-20, 09:35 AM
#4
RX-7 Bad Ass
iTrader: (55)
For now, just get it hooked up. The AST has been covered to death, you can search around and find a lot about it.
The very top nipple just under the radiator cap on the AST should go to the overflow tank. When the coolant warms and expands, some is pushed into the tank. When it cools, some is sucked back from the tank.
With the car cold, make sure the coolant in the car (check both caps) is full to the top. The AST should have a regular radiator cap with a spring plunger on it. The other cap stock is a flat cap with no spring, if someone put a regular radiator cap there that's OK. You just don't want a flat cap on the AST.
Also, make sure the overflow tank is filled to the Max line. You do NOT want it filled to the top - you have to have room for coolant to go into the tank when the engine warms up. The dipstick will show you how far it's filled.
Dale
The very top nipple just under the radiator cap on the AST should go to the overflow tank. When the coolant warms and expands, some is pushed into the tank. When it cools, some is sucked back from the tank.
With the car cold, make sure the coolant in the car (check both caps) is full to the top. The AST should have a regular radiator cap with a spring plunger on it. The other cap stock is a flat cap with no spring, if someone put a regular radiator cap there that's OK. You just don't want a flat cap on the AST.
Also, make sure the overflow tank is filled to the Max line. You do NOT want it filled to the top - you have to have room for coolant to go into the tank when the engine warms up. The dipstick will show you how far it's filled.
Dale
03-21-20, 10:26 AM
#5
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and blow through the overflow hose (~1psi is plenty) they like to clog.
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