Radiator Adapter Fitting Options for a 2012 GMC Sierra 1500 4.6L V6

Updated 04/09/2013 | Published 04/04/2013

Products Featured in This Question

Derale Radiator Adapter Fittings for GM

(46)

$17.42

Derale Transmission Line Compression Fitting Kit - 5/16" Line to 3/8" NPT Barb

(7)

$22.46

Derale Transmission Line Compression Fitting Kit - 3/8" Line to 3/8" NPT Barb

(24)

$23.07

Derale Transmission Line Compression Fitting Kit - 1/2" Line to 1/2" NPT Barb

(2)

$23.43

Derale Snap-In Radiator Adapter Fitting for GM

(274)

$16.69

Question:

This part will not fit a 2012 GMC Sierra 1500 4.6 V6. Looks like GM changed the lines/fittings. The lines are not 5/8. Do you know or have the correct fittings? I bought these at your sites recommendation.

asked by: Billy

Expert Reply:

I am not familiar with a 2012 GMC Sierra 1500 with a 4.6L V6 engine, so I did some research, but I was still not able to find a model that came with a 4.6L V6 engine. According to my contact at Derale, the 5/8 Inch Inverted Flare Fittings, # D13018, that you purchased should fit the 2012 and 2013 GMC Sierra 1500 4.3L V6. My contact at Derale also told me that they have not received any information that the fitting sizes have changed on this truck.

The adapter fittings that you purchased were designed to work with 3/8 inch lines. The 5/8 inch dimension on the fittings refers to the threaded portion of the fitting that would thread into your radiator. There are two radiator adapter fittings for GM vehicles from Derale. Derale offers thread-on fittings like part # D13018, that you purchased and a snap-in fitting, which requires the Snap-In Adapter, # D13035. You can determine the type of fittings that your truck requires by checking how your transmission lines connect to your radiator.

If your truck uses threaded fittings and the 5/8 inch inverted flare fittings do not fit, then we do not have any information as to the size that your vehicle requires. You may be able to contact a local GM dealer for this information or I can recommend other ways to install the transmission cooler.

Another installation option would be to use compression fittings. We have compression fittings for 3/8 inch diameter line, # D13032, 1/2 inch line, # D13033, and 5/16 inch line, # D13031. You will want to find the size of your transmission lines by measuring the diameter of your lines. I have attached an installation video on a 2003 GMC Yukon where our installer used compression fittings to complete the installation for you to check out.

You could also just cut and flare your transmission lines. I have attached an installation video where our installer cut and flared the lines on a Chevrolet Trailblazer for you to check out as well.