Repro RC-15 Radiator Cap Problems

[Bill Pritchard]

When I bought my Chevelle 8+ years ago, the original AC RC-15 radiator cap still functioned perfectly but it had a small rust pinhole on the top. For purely aesthetic reasons, I replaced it with a reasonably correct appearing reproduction, but kept the original. Yesterday, I was checking various fluid levels on the car and removed the radiator cap to check coolant level. When it came off, I noticed all this rusty scaly crud in the neck of the radiator. Looked at the cap and was unpleasantly surprised, to say the least....







Both the spring and the piece between the spring and the brass plate that seals againt the opening in the radiator neck were very heavily corroded, as you can see in the first picture. Many of these bits of corroded metal that broke loose can be seen in the second picture. You can also see the rubber ring that had been attached to the brass disc (to help in sealing) had completely detached from the brass disc.

Luckily, I still had the original cap (stored in the box that the repro came in, which you can also see in the pictures) so I dug it out and pressed it back into service. It still works fine, and has not one trace of corrosion in the 'working areas'.

If you have one of these caps, you might want to check it periodically to make sure this doesn't happen to you!

[Postsedan]

Bill,

I have seen this on many cars that I have placed repop caps on. Yes, I agree check them often.

Dan

[Bill Rose]

That condition can be extremely dangerous. If someone is working on a hot engine, and that cap flies off..........

[SuperNovaSS]

How would the cap fly off? It is held in place by the tangs on the main body.


Jason

[Bill Rose]

You're right, It probably wouldn't come off completely, but there's high pressure, and very hot anti-freeze/water that can escape, in a split second. I had a friend who spent the better part of last summer in a lot of pain, from severe burns, when he was burned with boiling anti-freeze. It looks like another piece of junk Chinese part, that can cause more problems, than I'd want to deal with.

[Ark68SS]

I'm the guy Bill R is talking about. What happened to me is when I stopped to gas the car up, coolant puked out of the overflow. When I opened the cap to add coolant, I inadvertently turned it to the fully open position instead of the pressure release position, and that's how I was burned. Totally my fault.
HOWEVER, the reason the car was losing coolant is because the cap spring had rusted and lost tension, and would not hold full pressure. Pics of the cap and more detail can be seen here-
http://www.chevelles.com/forums/showthread.php?t=298116
I've since bought one repro RC-15 cap (from Tamraz) and tested another, and neither of them held 15 lbs. One was 9, the other 11.
I'm currently using a Motorad brand cap I bought from Ausley's at Chevelleabration this year, and so far it's holding the correct pressure, which, to me, is more important than correct markings. :-)
I hope my experience will prevent anyone else from being injured.
BillL

[Bill Pritchard]

Hi Bill,

Nice to see you on this site [img]<<GRAEMLIN_URL>>/flag.gif[/img] Thanks for your post and the link to one of the threads on the Chevelle site about your terrible experience. One thing I neglected to mention previously is that when I removed this repro cap, my radiator was only about half full, so obviously I was losing coolant, too. Obviously you have invested some time and effort into checking out these repro caps....based on your findings, I think I will just purchase something that functions properly, appearance be damned [img]<<GRAEMLIN_URL>>/mad.gif[/img]