7 PSI radiator cap for my IDI

MTKirk

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Hey all, like the title states I need a part number for a 7 psi radiator cap.

I have a problem with my block heater building up too much pressure on the 13 psi cap. I have two 13 psi caps and they are both letting the pressure go over 20psi when it gets very cold. The higher pressure pushes out a little coolant from the lower rad hose to radiator connection. At operating temp I have no leak, nor did I this summer when the truck got very hot towing. My theory is, the cold makes the spring too stiff to let coolant into the overflow tank. When the truck warms up the spring functions normally and all is well. Sooo I'm thinking I'll put on a 7 psi cap in winter.

Thanks, and Happy Holidays!
 

chris142

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Stant # 10228... Any parts place can convert that number over to theirs.
 

riphip

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I've been using the 7 psi for years. Stant 328 with lever is correct I think. Easier on radiator also

Rick
 

MTKirk

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I've been using the 7 psi for years. Stant 328 with lever is correct I think. Easier on radiator also

Rick
Thanks, I like the lever kind. Stant caps start with 10 so I'm thinking the right part #must be 10328? Summit shows 10328 to be the cap for early '60's V8 trucks, so I'm guessing that's the right number. Plus the 10228 that chris posted up is just a digit away (indicating non-lever?) Think I'll go ahead & order.

Thanks guys
 

yARIC008

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I recently switched to the 7 PSI cap too. I forget who it was on here, maybe type4 that said he had been running one for years without cavitation issues. Figured half the pressure would make half the leaks...
 

opusd2

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This comes at the right time as I was looking at changing my cap as well. Thanks!
 

Rot Box

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Been seeing the exact same issue on mine.

Going to pick up a lower psi cap in the morning. Thanks everyone for the thread/info.
 

Runningaford

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I'd certainly like to hear others weigh in on this. I remember reading a caviitation article which spelled out I believe the importance of the higher pressure cap to safeguard against cavitation.
 

CDX825

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Switched mine to a 7lb cap years ago as well. Less likely to leak that way. I also highly recommend constant torque hose clamps.
 

lotzagoodstuff

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Hey all, like the title states I need a part number for a 7 psi radiator cap.

I have a problem with my block heater building up too much pressure on the 13 psi cap. I have two 13 psi caps and they are both letting the pressure go over 20psi when it gets very cold. The higher pressure pushes out a little coolant from the lower rad hose to radiator connection. At operating temp I have no leak, nor did I this summer when the truck got very hot towing. My theory is, the cold makes the spring too stiff to let coolant into the overflow tank. When the truck warms up the spring functions normally and all is well. Sooo I'm thinking I'll put on a 7 psi cap in winter.

Thanks, and Happy Holidays!

Just wondering: when was the last time you had your lower radiator hose off? A little corrosion could be the cause of your leak. Nothing wrong with changing your cap, but a clean/dry lower radiator connection might be a nearly free fix and allow you to run your current 13 psi cap.

Small coolant leaks are annoying. Good luck whichever method you apply.
 

franklin2

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I heard also that the higher pressure may help prevent cavitation. But cavitation has always been one of those mysterious phenomenons that you have to read about and just believe what you read. I did run a 7 psi for awhile trying to keep my rotten radiator from leaking till I as able to buy a new one.

One thing you will notice with 7lb cap, your water level in the overflow will change more dramatically. When the engine gets hot, there will be more coolant in the overflow with a 7lb cap.
 

chris142

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We do not like the lIke the lever caps. They seem to fail more often than a regular cap. Coolant boils up around the rod that the lever moves.
 

MTKirk

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Just wondering: when was the last time you had your lower radiator hose off? A little corrosion could be the cause of your leak. Nothing wrong with changing your cap, but a clean/dry lower radiator connection might be a nearly free fix and allow you to run your current 13 psi cap.

Small coolant leaks are annoying. Good luck whichever method you apply.
Brand new Champion Radiator and new gates hose. This is only happening at very cold Temps. Single digits F.
 

MTKirk

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Switched mine to a 7lb cap years ago as well. Less likely to leak that way. I also highly recommend constant torque hose clamps.
Yeah, I think this is the way to go. Do you have a part # for clamps that are working for you?
 
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