I think the o-ring in the cap has failed. I posted earlier about the leaks on this truck, and I thought the passenger leak was actual engine oil. But, since I am STILL using PS fluid for my pump, its pretty similar viscosity to my 10W-30 synthetic oil. Long story short, after replacing the PS pump, it was still leaking. I was already dealing with a leak from the rear cap on the driver side (minor PITA, but I fixed it!) but I couldn't figure out what the leak was on that side, seeing as there was no oil in the timing cover (thank goodness). The stupid leak was traced to the stupid cap. Now, where the heck is this part? I could JUST buy the cap, but it seems a waste:
http://www.toyotapartsdeal.com/oem/t...teering,,44305

 

I have to look closer but if your sure it is a o ring that seals the cap just get another one.

Most auto parts used to have a nice selection of O rings now you might need a industrial supplier

I doubt Toyota has a number for it when a dealer tech has a leaky one there just going to replace the cap

Myself if I did not have the O ring I would just replace the cap

Looking closer

Funny my cap has a gasket and they do wear out maybe yours is gone??

Since in theory there is really no pressure in the reservoir why is yours pushing out fluid ??

Over filled and when the fluid gets hot out the cap is the only place it can push out.

 

Honestly, no idea. All I know is that it is dripping out of the top and pooling a bit in the tool catcher. Maybe I overfilled it during the bleeding process, I'll monitor it over the next couple of days

 

I don't think I have ever seen one that didn't show evidence of having leaked fluid out of the cap and onto the tub. Even Our 2009 Tacoma is greasy up top by the cap.

 

Yeah, I just drove it a while, and it smelled of oil dripping on the manny, but I didn't feel any substantial oil where it was leaking last time, but the PS fluid looked WAAYYYY over filled.