I am planning on replacing o-rings of fuel injectors. The Haynes Manual says that I should lightly lubricate the rings with "light grade oil," but I am not sure what "light grade oil" means.

Can I use a little bit of engine oil I have (Mobile 1, 5W-30) to lubricate them? If not, exactly what kind or brand of oil should I get?

 

Engine oil or vaseline.

 

Thanks. I never thought of vaseline, though.

 

vaseline works great! Just make sure you don't overdo it at all.

 

while you can use petroleum based products (vaseline is a petroleum based product) for o ring lubrication, it is NOT advisable. you should instead use silicone grease. rubber can have serious reactions to petroleum based products. they can swell and soften as a result of using petroleum based lubes for o rings. this leads to the potential for failure. stick to the smart side and use silicone based grease.

and that we use rubber to keep petroleum products from leaking is a mystery (sarcasm). must be cheaper than other methods.

http://en.wikipedia.org/wiki/Silicone_grease

 

Thats freakin hilarious, because last I checked gasoline was petroleum based too. All O-rings are not created equally.

 

O-rings are neoprene are not affected by petroleum products.

 

O-rings in atomotive engine applications are neoprene and not affected by petroleum products.