overflow tank
Thread Starter
Instructor
Joined: Jun 2018
Posts: 110
Likes: 3
overflow tank
Hello Everyone
Well after all the help i got adjusting my valves I discovered another potential issue.
The engine runs quiet enough for me to notice a knocking sound coming from my water pump.
After cooling I opened the radiator cap and noticed it was low.
So I filled it up and ran the engine with the cap off until the thermostat opened and a began filling it as the level went down.
Ran it a few times at 190 degrees no overheating at all.
Looking into the overflow tank I noticed a bolt plugging the overflow hose.
Also notice the hose from the radiator to the overflow tank has fine cracks and weeps coolant after I took it for a run after filling it up.
Question #1 there does the overflow hose attach to?
Question #2 its the system simply finding its happy level and spewing the excess?
Coolant level is now a little lower, I can see 3 fins above the level of the coolant in the radiator.
Thanks for all the advice.
Well after all the help i got adjusting my valves I discovered another potential issue.
The engine runs quiet enough for me to notice a knocking sound coming from my water pump.
After cooling I opened the radiator cap and noticed it was low.
So I filled it up and ran the engine with the cap off until the thermostat opened and a began filling it as the level went down.
Ran it a few times at 190 degrees no overheating at all.
Looking into the overflow tank I noticed a bolt plugging the overflow hose.
Also notice the hose from the radiator to the overflow tank has fine cracks and weeps coolant after I took it for a run after filling it up.
Question #1 there does the overflow hose attach to?
Question #2 its the system simply finding its happy level and spewing the excess?
Coolant level is now a little lower, I can see 3 fins above the level of the coolant in the radiator.
Thanks for all the advice.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
H-m-m-m-m-m-. Why would someone plug the overflow hose?
A. The Rad cap has too low of pressure setting and blows very easily.
B. The overflow tank has a hole in it that somebody didn't want you to find.
A. The Rad cap has too low of pressure setting and blows very easily.
B. The overflow tank has a hole in it that somebody didn't want you to find.
Thread Starter
Instructor
Joined: Jun 2018
Posts: 110
Likes: 3
Hello Everyone
Well I replaced the radiator cap as well as the leaky hose from the radiator to overflow/expansion tank.
All is good no overheat-
no loss of fluid
no hose collapsing
knocking sound still there but faint
thanks.
Mike
Well I replaced the radiator cap as well as the leaky hose from the radiator to overflow/expansion tank.
All is good no overheat-
no loss of fluid
no hose collapsing
knocking sound still there but faint
thanks.
Mike
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
FWIW: if you have a fill cap on the radiator, you do not need the expansion tank on the fender skirt. A previous owner has swapped the radiator or needlessly added the tank thinking it was needed. The cooling system should have only one fill cap.
Drifting
Joined: Jun 2015
Posts: 1,343
Likes: 753
From: Doctors Inlet Florida
Your car originally came with an aluminum radiator(you can tell by the fan shroud) that did not have a cap on it, coolant was added to the radiator thru the aluminum coolant reservoir.
You only want one cap on your cooling system.
You only want one cap on your cooling system.
Thread Starter
Instructor
Joined: Jun 2018
Posts: 110
Likes: 3
So should i take the radiator cap off the radiator and swap it with the cap that is on the overflow tank?
Drifting
Joined: Jun 2015
Posts: 1,343
Likes: 753
From: Doctors Inlet Florida
You have some options.
1. Replace the radiator with the correct one(expensive)
2. Remove radiator and take it to a radiator shop to see if they could remove/weld up the inlet and continue to use the expansion tank.
3. Remove the expansion tank which will require new heater hoses and some kind of overflow reservoir.
4.Buy a 22lb. cap and put it on the radiator and use your new 16lb. cap on the expansion tank. (i'm not sure that would work but it's worth a try)
I would try #2 first and then try #4. I like using the expansion tank because it is the highest point in the cooling system.
1. Replace the radiator with the correct one(expensive)
2. Remove radiator and take it to a radiator shop to see if they could remove/weld up the inlet and continue to use the expansion tank.
3. Remove the expansion tank which will require new heater hoses and some kind of overflow reservoir.
4.Buy a 22lb. cap and put it on the radiator and use your new 16lb. cap on the expansion tank. (i'm not sure that would work but it's worth a try)
I would try #2 first and then try #4. I like using the expansion tank because it is the highest point in the cooling system.
Race Director
Joined: May 2006
Posts: 18,692
Likes: 2,572
The radiator needs what is called a blank cap, this type of cap only has the large rubber seal to seat it against the top of the neck. There is no spring or anything else under the cap. These type of caps were used on 1970's Jaguars. The part number is eac3424 and I found them at www.xks.com. The expansion tank needs a special cap to prevent a electrolysis interaction between the coolant and the aluminum tank, RC26. All the Corvette vendors carry them, below is an example.
https://willcoxcorvette.com/corvette...15-rc-26-67-72
https://willcoxcorvette.com/corvette...15-rc-26-67-72
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