Lets Play "What is the PN"

[Easy Ed]

The part number does come up when Googled with pictures https://www.google.com/search?q=52458184&rls=com.microsoft:en-US:IE-SearchBox&tbm=isch&tbo=u&source=univ&sa=X&ei=34bYU s2pGsb4yAHPyYCgDQ&ved=0CDYQsAQ&biw=1366&bih=652 to compare, most likely used on may GM vehicles. It looks though in the pictures that you do not get the valve core item 24, (valve core looks the same as a tire valve stem valve core) so if you are leaking out the top the valve core could just need screwed in to seal, can get a valve core tool at a parts store. If you are leaking farther down on the fitting near the joint of the two mating parts it could be the sealing O-ring has gone south. O-rings are cheap and easy to get, hell I deal with them every day in our business.

Good luck, Ed

Edit: Ignore the above, it appears to not apply. It looks as though HUMTECH may have gave you the parts number to the front one (it appears to be replaceable) and you need the tube and fitting the is in the rear of the attached picture. Went out to the truck to look (damn the garage floor is cold) and took the picture. Now we need to find that part number for #34 like you requested. I will look around the web to see what I can find or maybe HUMTECH can see if he can get the part number.

Edit: No luck finding the part number, sorry.