[SaberOne]

Your cap needs to be replaced if that's photos of your car, OEM part numbers is what i provided, don't know about old/new numbers but via GM that is the OEM part number radiator cap, your hoses will be/look fine after cap replacement and one heat cycle. I rushed to order without digging into info, hoses will not need replacing was the consensus and i agree as they went back to original form. I had already order the upper one for few $$ i will keep on the ss parts shelf.

Parts shelf? …parts shelf?!
'We don't need no stinking parts shelf! My third bedroom/office/sewing room is now a parts room and would embarrass some dealerships. Not bragging; just a lot of mistakes and some good ole' fashion hoarding. I will stop by the local NAPA to see if I can snag one or two. Thanks for the tip. Nice photo by the way ✌

 

[Jason Lester]

Seems like one could just replace the o-ring

 

[DarthMalaguti]

Just checked and the hoses are partially collapsed (27K miles). I had the coolant flushed and replaced at 25K but neglected to replace the radiator cap. Time for a trip to NAPA.

Thanks for the heads-up.

 

[SaberOne]

Okay, I finally replaced the little bas***d. 🤓 I ordered a spare as there is no apparent indication when it will fail again. For what its worth, the ‘DuraLast’ seems more solid than the somewhat flimsy ‘AC DELCO.’
Anywho, I plan to make a habit of inspecting the hose anytime I open the bonnet.
🦘…

 

[SS WOT]

The small holes on my original cap were blocked, I imagine thats the pressure relief. You can see them on left hand side of Saber's pic. Didn't give it a thought but I think that is the pressure relief Benb446 is referring too? Good to know if on road trip...

I recently replaced my cap, because my hoses were collapsed when cooled off. After looking at the old cap, the pressure release part was stuck. Used a screw driver, popped it loose. And started working fine. Since I had already replaced it, now I just have a spare cap.

Ok, finally replaced the little bas***.
View attachment 294840

 

[Benb446]

The circle metal piece on mine was stuck down. So that's what i was referring to. I'm guessing it's heat activated. Heats up, moves down to seal and pressurize, cools and moves up to vent.

 

[rjcalif]

I had picked up a cap on Amazon last year just in case. Only 35,000 miles my OE has not failed but it's only a matter of time just like a dead battery

 

[FCHolden]

54K miles and 6.5 years of driving but noticed the “collapsed “ hoses yesterday as a result of this thread. Stopped by the local Chevy dealer this afternoon and picked up a new radiator cap. All is good again. The O-Rings on the two caps looked like the ones in the photos and it appeared that the mechanism had stuck in one position.

A thousand miles ago, I replaced the coolant. Should have replaced the cap then.

Thanks all for this thread.

 

[DarthMalaguti]

Mods, your thoughts on a sticky for a failed radiator cap? Not a lot of reference to it but I did see that @wilkin4 reported it as far back as Feb 2018.

 

[Pinetree]

Done, Also recommend setting a "bookmark" save on posts that have part numbers in them.

 

[McSkillet]

Walmart has them too. At the time of this posting they were $11.19 each for OE ACDelco GM# 13502509, ACD# RC115. I have a W+ membership so shipping was free.

 

[16PB6MT]

I bought a new cap just to have on hand without even looking under hood. Opened it to put charger on battery today and both hoses are collapsed.... thanks SS Forums for the heads up

 

[TheGenz66]

I know this is in recent post so not to high jack I'll drop this here.
While cleaning the catch can I noticed the lower radiator hose was collapsed to about half of it's diameter. Not sure how long this has been going on. Hoses feel a little soft. Working on ordering hoses, No one vendor has all 4 pieces. In the meantime I replaced the cap and hoses aren't collapsing. Mentioned by another member is the O ring is flattened. Here is a pick and something to check for when inspecting radiator fluid. Original on left.

View attachment 294766

I had the same issue with my 2014 with 33K miles. I would never have noticed the partially collapsed hoses had I not read about it on this forum. So thank you. I purchased a new cap from Napa. Problem solved. In my opinion, it is not that the o-ring is flattened but I noticed the 4 small holes were blocked with what looks like rubber. Don’t know where the rubber came from. The flattened o-ring is the same diameter as the new o-ring. What ever the failure mode is, I am just happy the issue is resolved.

 

[SS WOT]

Mine was too, some sort of diaphragm. Plus there are two tubes at different heights in the neck of the radiator. Serving some sort of dual function to drive up maintenance cost...

I had the same issue with my 2014 with 33K miles. I would never have noticed the partially collapsed hoses had I not read about it on this forum. So thank you. I purchased a new cap from Napa. Problem solved. In my opinion, it is not that the o-ring is flattened but I noticed the 4 small holes were blocked with what looks like rubber. Don’t know where the rubber came from. The flattened o-ring is the same diameter as the new o-ring. What ever the failure mode is, I am just happy the issue is resolved.

 

[SS WOT]

Been gathering up the hoses as no 1 supplier has all the pieces for upper and lower. If you look at part #18:

Radiator & Components for 2015 Chevrolet SS | GM Parts Store

www.gmpartsdirect.co

It appears twice, the second #18 at end of part list is bogus. After GM parts direct cancelled order for 92457862, so I ordered 12600254. After waiting 3 weeks, I got a 6" piece of 3/16" hose. Not coolant bypass.
Just a heads up. I am trying to keep car as original as I can.

 

[tanisdwninit]

Ran across this thread few months back and no surprise when I checked my 2017 AT upper and lower were collapsed when cool. Replaced the radiator cap with RC115, they are no longer collapsed.

Meant to post when I fixed, thanks all for posting.

 

[SS WOT]

I was cleaning up my shortcuts on PC. This is good reference to drop in here.
Continental Belt and Pulley part finder.

Continental Elite Online Parts Catalog

ShowMeTheParts is changing how the world finds replacement parts for their vehicles.

wholesale.mycontiparts.com

 

[DarkKn1ght]

This is a really silly problem to have. I've noticed this with mine as well. I'm a Mopar guy who's SS is my first non-Mopar. Mopars have a spring in their radiator hoses to prevent collapsing. I really thought it was odd that Chevy's don't.

 

[willy92]

Replace the radiator cap.

It's not venting and is causing a vacuum in the system during cool down.

 

[SS WOT]

With all the new owners lately, I thought this a good time to bump this thread. Something most of us never had on the check routinely list.