Carrs 4x4 Expansion Tank Radiator Cap

donniefitz2

Well-known member
Sep 15, 2020
138
56
Scottsdale, AZ
fitzventure.com
I have the aluminum Carrs 4x4 coolant expansion tank on my Disco 2. I really like it but, it dribbles coolant out the pressure relief hole (under the traditional radiator cap). My system is not over pressurized. If I use the plastic tank everything is fine.

I noticed that the radiator cap used for this tank is a 16psi cap. The coolant pressure for these trucks is supposed to be 20psi from what I have read. So, it makes sense that this thing would piss coolant out because the cap is rated 4psi too low.

I'm going to try putting on a 20psi cap to see what happens.

Has anyone else used this aluminum tank before? Did you have this problem?
 
Aug 20, 2007
2,727
45
Nashville TN
I was in my mechanic's shop yesterday and he was showing me one where he said the spring was too loose stock, and he likes to tighten up the nut that holds the spring on so it holds pressure better, but not to tighten it a ton. I'm not saying you should do that, but it might be worth testing out?
 

donniefitz2

Well-known member
Sep 15, 2020
138
56
Scottsdale, AZ
fitzventure.com
I was in my mechanic's shop yesterday and he was showing me one where he said the spring was too loose stock, and he likes to tighten up the nut that holds the spring on so it holds pressure better, but not to tighten it a ton. I'm not saying you should do that, but it might be worth testing out?
That's definitely worth a try. I'll give it a shot. Thanks.