What radiator cap do we trust?

[WVJeep304]

So I've noticed some dried coolant under the hood a time or two. I'd clean it up and tell myself to keep an eye on it to see where it's coming from. Well, what would actually happen is next time I'd open the hood and see dried coolant, I'd gaslight myself into believing I never cleaned it up the first time .


This time, I kept myself honest and today, I opened the hood and saw this.

This Motorad cap was put on around 2 years ago, and I believe this has been happening for nearly the entire time. Any ideas where to find a decent quality cap?

 

[JKP]

I've got the lever vented ones on my YJ and TJ. One is a Carquest, the other a Murray, no issues with either. Carquest is def a MotoRad, not sure about the Murray.

 

[DirtDawg]

When I refreshed my cooling system July 2025 at 90k miles (complete parts replacements, other than previous radiator and apparent original water pump), I read lots of comments here and elsewhere and chose this OEM radiator cap (noting paid $19). No leaks whatsoever subsequently: Genuine Chrysler 55116901AA Radiator Cap

 

[Feralkid]

I use stant lever caps and never had a problem

 

[WVJeep304]

Stant and Murray were previously my go-tos, but i heard a couple of years ago they are both now Motorad. Any truth to that? I've not had much success with Motorad stuff, but sometimes it's the only option, at least locally.

Edit: a quick Google search says it's true. Hmm...

 

[DirtDawg]

Stant and Murray were previously my go-tos, but i heard a couple of years ago they are both now Motorad. Any truth to that? I've not had much success with Motorad stuff, but sometimes it's the only option, at least locally.

Edit: a quick Google search says it's true. Hmm...

The radiator cap on mine when removed and discarded was a Motorad, which hadn't leaked to my knowledge. So, I chose the linked "genuine" Mopar cap, which might have been counterfeit per at least one user comment but made in China regardless, which I don't recall noticing. If so and since Mopar doesn't make radiator caps or any such components, perhaps simply a Motorad stamped with the Mopar P/N...

 

[Travis05Rubi]

I run an oem from tbe dealer. Was 25 bucks and its definitely quality compared to the store brand I had before.

 

[GoldenGorilla]

I read lots of comments here and elsewhere and chose this OEM radiator cap (noting paid $19). No leaks whatsoever subsequently: Genuine Chrysler 55116901AA Radiator Cap

Same, though I bought mine 7 or 8 years ago and it's just been sitting there. Just swapped from my original cap (which I kept as a backup). All good

 

[MikeE024]

So I've noticed some dried coolant under the hood a time or two. I'd clean it up and tell myself to keep an eye on it to see where it's coming from. Well, what would actually happen is next time I'd open the hood and see dried coolant, I'd gaslight myself into believing I never cleaned it up the first time .


This time, I kept myself honest and today, I opened the hood and saw this.
View attachment 696263

This Motorad cap was put on around 2 years ago, and I believe this has been happening for nearly the entire time. Any ideas where to find a decent quality cap?

I got my Mopar radiator cap on Amazon

 

[JKP]

The radiator cap on mine when removed and discarded was a Motorad, which hadn't leaked to my knowledge. So, I chose the linked "genuine" Mopar cap, which might have been counterfeit per at least one user comment but made in China regardless, which I don't recall noticing. If so and since Mopar doesn't make radiator caps or any such components, perhaps simply a Motorad stamped with the Mopar P/N...

Well, MOPAR thermostats are stamped MotoRad now, so most likely the caps are made by them too.

 

[MikeE024]

Well, MOPAR thermostats are stamped MotoRad now, so most likely the caps are made by them too.

Motorad is the OEM manufacturer. This means they make that part to Mopar’s specs and quality standards.

 

[JKP]

Maybe... A lot of the MOPAR parts for the older vehicles are not the same quality as the originals.