Coolant expansion tank cap - pressure problem
09-22-19 | 01:31 PM
#1
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Joined: Feb 2013
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From: ca
Coolant expansion tank cap - pressure problem
Has anyone noticed that on gen-1 LS (maybe on the 2nd gen too?), the coolant expansion tank, or reservoir in everyday speak, will rather blow the coolant level sensor than open the cap in case of high pressure?
To make things worse, I only now realized that at some point few months ago, I had increased pressure and it blew my heater valve and my OEM radiator, but the stupid cap did NOT open!!! I even found tiny trace of coolant around the fill hole at the front (so it even leaked there, that's how high the pressure was), but NOTHING around the cap.
Now, that angers me. OK, there is a chance that my cap is old and not performing to spec (I may have to check that), but so many others complain of the level sensor leaking, which points to a problem with the cap not letting the pressure out, that I am begging to think that we have a systemic problem with that cap. A $20 part that can inflict expensive damage.
The rated pressure of the cap is 88kpa, which is 12.7psi. That sounds a bit too high to me. Any way to lower that? Any "adjustable" aftermarket caps" I would much rather have a leak at the cap then have to replace radiator ($350), heater valve ($100), coolant level sensor ($200) and who knows what else.
To make things worse, I only now realized that at some point few months ago, I had increased pressure and it blew my heater valve and my OEM radiator, but the stupid cap did NOT open!!! I even found tiny trace of coolant around the fill hole at the front (so it even leaked there, that's how high the pressure was), but NOTHING around the cap.
Now, that angers me. OK, there is a chance that my cap is old and not performing to spec (I may have to check that), but so many others complain of the level sensor leaking, which points to a problem with the cap not letting the pressure out, that I am begging to think that we have a systemic problem with that cap. A $20 part that can inflict expensive damage.
The rated pressure of the cap is 88kpa, which is 12.7psi. That sounds a bit too high to me. Any way to lower that? Any "adjustable" aftermarket caps" I would much rather have a leak at the cap then have to replace radiator ($350), heater valve ($100), coolant level sensor ($200) and who knows what else.
09-22-19 | 03:49 PM
#2
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Joined: May 2018
Posts: 649
Likes: 63
From: TX
Has anyone noticed that on gen-1 LS (maybe on the 2nd gen too?), the coolant expansion tank, or reservoir in everyday speak, will rather blow the coolant level sensor than open the cap in case of high pressure?
To make things worse, I only now realized that at some point few months ago, I had increased pressure and it blew my heater valve and my OEM radiator, but the stupid cap did NOT open!!! I even found tiny trace of coolant around the fill hole at the front (so it even leaked there, that's how high the pressure was), but NOTHING around the cap.
Now, that angers me. OK, there is a chance that my cap is old and not performing to spec (I may have to check that), but so many others complain of the level sensor leaking, which points to a problem with the cap not letting the pressure out, that I am begging to think that we have a systemic problem with that cap. A $20 part that can inflict expensive damage.
The rated pressure of the cap is 88kpa, which is 12.7psi. That sounds a bit too high to me. Any way to lower that? Any "adjustable" aftermarket caps" I would much rather have a leak at the cap then have to replace radiator ($350), heater valve ($100), coolant level sensor ($200) and who knows what else.
To make things worse, I only now realized that at some point few months ago, I had increased pressure and it blew my heater valve and my OEM radiator, but the stupid cap did NOT open!!! I even found tiny trace of coolant around the fill hole at the front (so it even leaked there, that's how high the pressure was), but NOTHING around the cap.
Now, that angers me. OK, there is a chance that my cap is old and not performing to spec (I may have to check that), but so many others complain of the level sensor leaking, which points to a problem with the cap not letting the pressure out, that I am begging to think that we have a systemic problem with that cap. A $20 part that can inflict expensive damage.
The rated pressure of the cap is 88kpa, which is 12.7psi. That sounds a bit too high to me. Any way to lower that? Any "adjustable" aftermarket caps" I would much rather have a leak at the cap then have to replace radiator ($350), heater valve ($100), coolant level sensor ($200) and who knows what else.
https://www.rockauto.com/en/catalog/...,radiator,2172
09-23-19 | 08:04 AM
#4
Pole Position
Joined: Dec 2009
Posts: 3,277
Likes: 314
From: ct
And yes, these engines sure do get hotter then you'd think.peterls; I've had the sensor go bad and leak on both my LS's. Not sure if the caps were bad, I never changed them. I just put some kind of sealer around the sensors. Don't ask what it was cuz I don't know. It was a sealer we used at work on our spray foam insulation machines. Wish I grabbed some before I stopped working.
09-23-19 | 11:50 AM
#5
Racer
Joined: Sep 2018
Posts: 1,383
Likes: 66
From: California
09-23-19 | 08:16 PM
#6
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From: Japan
I worry that the cap you used was not working right when you had the problem.
09-24-19 | 07:44 AM
#7
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Joined: Feb 2013
Posts: 752
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From: ca
Thanx everyone for the responses!
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