Rejuvenating rubber firewall grommets

[monkeymissile]

Is there a good way to rejuvenate those chunky rubber firewall grommets? Mine are hard and no longer fit well. I have heard soaking them in brake or tranny fluid works. Any other ideas?

Thanks,
Justin

[w30bob]

Justin,

I was thinking the same question. I'd be a bit leary of brake fluid.....the grommets are made of a foam-type material and brake fluid might just eat them up. I was thinking along the lines of rubbing dielectric grease on them....but there may be better solutions. I'm anxious to hear what others have to say.

regards,
bob

[WarrenD]

My experience has been that nothing will replace the natural oils in the rubber nor the damage done by time. Most everything I have tried has accelerated the decay or disintegrated the part on contact. If you want to preserve the look (but not the flexibility) you could use an epoxy. It will make the part hard and you'll likely have to cut any wires going thru it to replace it. If there is a motion thru the grommet, best to replace it.

[monkeymissile]

Hmm, pretty sure my grommets are solid rubber and not a foam. I'm talking about the (2) split ones for the L&R sides of the front wiring harness.
I have one that's in bad shape and another that's good, but hard. I may try to make a mold and cast some in silicone, then I could sell them!
I'll try the bad one in some brake fluid, nothing really to lose.....

[w30bob]

Hey Justin,

My bad....I thought you were talking about the oval grommet with the big and little hole over on the passenger side of the firewall. I've never done it before, but I would expect molding new ones wouldn't be that hard if you have an original to make a mold from. Let's us know how the silicone version turns out.

thanks,
bob

[N1VSM]

I've had the most luck soaking parts in Gibbs. Let me rephrase that ... the only thing that I have ever used that showed even the slightest hint of softening old rubber is Gibbs.

http://www.gibbsbrand.net/home.html

The claims read like snake oil, but don't knock the stuff until you have tried it. Best penetrating oil I've ever used.

[Tanner]

Straight Glycerin on old rubber... many people have used glycerin to try & bring some 'life' back into old rubber parts. Old car crowd has used it for years.

http://www.cvs.com/shop/product-detail/ ... uId=483707

If you don't plan to use the parts immediately after treating, place them in sealed plastic bags to keep them 'lubed'.

It SHOULDN'T create any swelling issues in rubber parts, but if swelling does occur & lasts longer than 5 hours, you might visit a doctor...

'Tanner'

[monkeymissile]

I have glycerin too so I'll try that as well, thanks!

[w30bob]

Tanner.......that last part was funny!! Good one.

bob

[jordankjcm]

I've got the same issue with those large grommets that the wiring harness passes through (each side). They were so brittle and bonded to the firewall that I had to cut them out as I am in the process of replacing my wiring harness. Is there a source for these grommets, either new (preferred) or NOS?

Thanks,

Jeff

[m-37Bruce]

The grommets were available, I bought a pair of 'em from Sid Beck a couple of years before he passed away. I had thought that Brent Mullins bought his stock, a call to him said other wise.

[mike_l]

Wait, what? Brent didn't buy up Sid's stock? That was the general info at the time and I'd noticed a "Dodge" link added on his website afterward (though nothing ever comes up if you click it).

There was a fellow out of Michigan, IIRC, that had some repro grommets made and was selling them for a while at the local shows here in the midwest. I'll look around and see if I can find his contact info. Can't say I remember any on his table at the last show I saw him at.

[m-37Bruce]

Good luck with that, Sid had so much stuff, railroad cars full from what I recall?

[Cal_Gary]

I don't know what Sid had, but the late Jack Tomlin had railroad cars of stuff above and underground too-told me that's where he created his "indoor rifle range". Figures, as he was loading up a 30 cal belt when I arrived on his site a few years back.
Gary

[scooterbob]

Hi Justin.
I would consider windshield urethane glue over and around the grommet. It may well cover the cracks and give you a fresh seal. $20 a tube at Carquest. Alternatively ask for a spent tube at the glass shop. My 2 cents worth.
Wolff.