Gasket kit, expiration date?

[Dericsh]

I searched but didn’t see any threads like this. How do we feel about gasket kits having an expiration date? Are all the gaskets going to turn to dust if I open it?

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Thanks in advance for sharing your experience,
Deric

 

[BLACK'98DSM]

They usually have an expiration date if it contains rubber components. Regardless of climate control, rubber components will harden a certain degree over time (as I'm sure you already know).

Will they fall to dust? Likely not. Will they be soft enough to allow a good seal? Nope.

Not sure if you've ever tried, but take a NEW valve cover gasket from the packaging and stretch it. It's pretty crazy how far you can stretch it, usually 3x the standard length. Try the same thing with some old gaskets, they break long before this point.

I'm curious to see what's inside that package now. Some early stuff for sure. I definitely wouldn't use any of the rubber components though.

 

[Dericsh]

They usually have an expiration date if it contains rubber components. Regardless of climate control, rubber components will harden a certain degree over time (as I'm sure you already know).

Will they fall to dust? Likely not. Will they be soft enough to allow a good seal? Nope.

Not sure if you've ever tried, but take a NEW valve cover gasket from the packaging and stretch it. It's pretty crazy how far you can stretch it, usually 3x the standard length. Try the same thing with some old gaskets, they break long before this point.

I'm curious to see what's inside that package now. Some early stuff for sure. I definitely wouldn't use any of the rubber components though.

Good points,

new valve cover gaskets are definitely a lot more flexible than the ones they are replacing. Those have been exposed to hundreds or thousands of heat cycles.

I kinda wondered about how long it would be good for past some printed/made up expiration date, considering it’s sealed and, MAYBE, kept in a conditioned space.

This is for a 1G engine gasket kit. So, a lot of paper and a few rubber things as well. I wonder how long after manufacturing it’s considered expired? 5-10 years possibly?! we are pushing a quarter-century past EXPIRATION, not manufacture date! How am I this old?! .

 

[danl]

Many Mitsubishi paper gaskets have rubber embossed onto them. I don’t think the paper itself will age out, but I’d like to know if someone has information to add here.

One of the things I learned from my other hobby, mountain biking, is that rubber deteriorates when exposed to UV light. The bike tire manufacturers do not put as much UV protect in the tires as a car tire because they are not expected to be stored outside. I’ve used NIB tires that were over 2 years old and they were fine. I’ve had tires go bad in less than a year due to UV damage. It is likely the rubber used in automotive gaskets has zero UV protectant. So keep the gaskets away from UV.

I have a couple oem front case and thermostat housing gaskets. I used a thermostat housing gasket, circa 2006-2008 in 2023 and it was still flexible and pliable.

I used a non-oem valve cover gasket that is likely 10+ years old and it was flexible, pliable, and does not leak.

I’m confident that if you expose either of these to sun for a couple hours per day for a year from new, they would be trashed.

FYI these gaskets were stored outside, in a barn, sealed in a plastic bag, and the bags put into a plastic storage container.

 

[pauleyman]

I haven't been overly concerned with my stored rubber gaskets either. I have bins full of stuff I've had for years and all of it is still pliable.