Replacement o-ring

[tmbr_wulf]

I'm doing some maintenance and want to replace the o-ring on my dipstick and head cover but they seem crazy expensive online.  Are these common enough that I could pick them up at the hardware store?  When I wrote down what I assumed was the size from the parts fiche they did not match up with the available standard or metric o-rings in the plumbing dept.  I'm going to take them off and run down to the store again to physically match them up, I was just wondering if anyone else had experienced this, because hardware o-rings would be about 4 times cheaper.

And just to help make this searchable, oring, "o ring", o-ring, orings, "o rings" o-rings.   

[Janx101]

You forgot o_ring!

[Big Rich]

If I'm not mistaken, the oring around the dipstick isn't rubber - I think it is made of something similar though. If you use plain orings from a hardware store, they heat up / dry out / get chewed up quickly.

[noworries]

Neoprene.

[The Buddha]

O rings from autoparts stores are usually made of BUNA-N - I believe its a very close relative of neoprene. Its resistant to heat, gas, oil and a lot of others - but it will not stand up to bleach. It is dimensionally stable under heat, oil etc.
The hardware store O rings - if it says rubber - obviously is made of rubber.
That stands up well to bleach, and heat, but it loses shape when exposed to rubber or gas.
That O ring - take it with you, or take the dipstick if the O ring is awol, and fit and check @ auto parts store.

Cool.
Buddha.

[tmbr_wulf]

Very sound advice.  I don't know why the auto part store didn't come to mind, why would I jump right to plumbing supplies?  Thanks!

[Janx101]

Plumbing supplies are fun! ... oooh lookit!  Wuzzat do?! .. lol

[The Buddha]

The schedule 40 section is pure gold ... bike parts, speaker parts anything you need can be cut and ground from plastic ...
Cool.
Buddha.