Aftermarket radiator - unused outlet rubber cap cracked

[Tahoe97]

A GM dealer installed an aftermarket radiator in my 97 Tahoe 2 years ago. One of the outlets just below the cap on this radiator was not required for my vehicle so the dealer tech capped it off with a rubber cap and clamp. I noticed today (see photo) that the rubber piece they used is cracked and poised for a blowout. It didn't even last 2 years. Lucky for me I noticed it today, even though I drove 200 miles several days ago in a rainstorm not knowing about this.

I will remove it tomorrow am. Does anyone have a good recommendation on how to seal this unused outlet off so that it lasts more than 2 years?

Thanks.

 

[OR VietVet]

It is rubber. Don't know the conditions you operate in. Sunny Arizona or bitter weather Alaska. Salt on the roads? I see lots of rust in that pic.

You can bet that, one size fits all, radiator came with that cap in the box with the radiator.

I think a quick fix would be to go to a hardware store and get the correct inner diameter high temp silicone hose piece and clamp a barbed brass plug in the end and clamp the other end to the radiator nipple.

 

[Tahoe97]

NC. Been in the mountains of NC, WV, NY, MA in the snow on numerous occasions so that is where the salt exposure is from over the past 20 years.

The cap that came with the radiator is clearly crap. Can't handle the heat. Your suggestion may be the ticket. I will go that route tomorrow.
Thanks!

 

[OR VietVet]

You want to make sure the hose, whatever it is, can handle the heat as well as the pressure created in the cooling system. Make sure the radiator cap is good too.

 

[Tahoe97]

We are on the same page. Heat and pressure are critical, which obviously wasn't considered with the ACME fix that the dealer installed 2 years ago. Cap is good and relatively new. I will head to the auto parts store and get some hose that is designed for radiator applications. The right size is the key so I need to take off the existing plug and bring it, also measuring the opening if I can.

 

[Big Mama]

See if you can trim down a cork to help you measure inner diameter. Had this same thing happen on a Volvo. The caps lasted about a year so Ron’s idea should work much better. Just remember to check it during oil changes and carry a spare cap and clamp just in case.

 

[Squirrelsmith]

Such ********. I had the same thing with my champion radator. Got ahold of champion and they said oh its not meant to be permanate. Really then what do you suppose i do? Put some hoakey piece of hose on it? Get the **** out of here! I welded mine

 

[Tahoe97]

Repair complete. I picked up a few inches of 5/8" heater hose from Advanced Auto Parts which has nylon braid within the rubber. The lame rubber cap installed by the dealer had no braid reinforcement so it just expanded with the heat and pressure and cracked almost wide open within 24 months. Picked up a brass fitting from Lowes to cap off the end. Before and after pix attached. I removed the overflow line for the pictures. That is back in place now. We'll keep an eye out for leaks and I will have a spare ready at all times. Thanks everyone.

 

[OR VietVet]

Such ********. I had the same thing with my champion radator. Got ahold of champion and they said oh its not meant to be permanate. Really then what do you suppose i do? Put some hoakey piece of hose on it? Get the **** out of here! I welded mine

All right, I'll bite, how do you weld plastic? UNIVERSAL radiators are cheaper for many reasons. Any rubber is never ever meant to last forever. Seals, molding, belts, hoses, caps......whatever, they don't last forever. It is the world we live in.

 

[OR VietVet]

Repair complete. I picked up a few inches of 5/8" heater hose from Advanced Auto Parts which has nylon braid within the rubber. The lame rubber cap installed by the dealerView attachment 236125 View attachment 236126 View attachment 236127 had no braid reinforcement so it just expanded with the heat and pressure and cracked almost wide open within 24 months. Picked up a brass fitting from Lowes to cap off the end. Before and after pix attached. I removed the overflow line for the pictures. That is back in place now. We'll keep an eye out for leaks and I will have a spare ready at all times. Thanks everyone.

Good call. I cannot tell in the pic but I would tighten the clamps just till you start to see rubber squeeze thru the slots where the screw threads of the clamp are. Once the rubber starts to ooze thru those slots it is all tight.

I just took a closer look at the pic and see that, if it was me, I would tighten just a bit more.
I also assume the brass fitting is barbed?