Ha, just about anything in the Hyundai owners manual tell you to take your car to your Hyundai dealer, even replacing a light bulb or repairing a leaky tire. Nearest Hyundai dealer is an 82 mile drive.
Was faced with the problem with my Cruze with a manual transmission, owners manual said to replace it 45K miles that I just hit. Only suppose to use GM part number 19259104 that the dealer sells for 40 bucks a quart, comes in a quart bottle, takes 2 1/2 quarts, that's 120 bucks plus tax! Guys that had it done with labor, over 200 bucks.
I looked at mine, for years, OE's were using regular motor oil for a manual, from my taste and feel, swore this stuff was Mobile One synthetic, so what is this 19259104 stuff? Did find a cross reference for Royal Purple HPS 5W-30 that claimed to be an exact replacement for 19259104 at 8 bucks a quart, but a drunken driver solved this problem for me. But not even sure why, was super clean and moisture free.
Hyundai says the AT fluid is red, will turn dark, but perfectly normal, ha, this is when I would replace the fluild, A Ford C4 in a motorhome really turned black and really had a heavy load, replaced it every 30,000 miles. My was to do it was to open a coolant line, put the output side into a large container and idle the engine. That would get all the fluid out.
Filters use to be common, history now, claim that still have one, but have to remove the AT first and take it apart to do it. Where the fluid really gets hot is at a red light in traffic, not helpless, switch the AT to neutral. I see the Elantra does have an external cooler, these help a lot.
How do I check for leaks? Easy, when backing out of my garage, just glance at the floor, should be clean and dry. Torque converter lockup really increased the life of AT fluid, no turbine slip. I should be good for 150K miles.
What really has to be changed, three years is my limit is brake fluid, still using Dot 3 that is hygroscopic, gums up and can stall ABS valves so you don't get any braking at all to any given wheel. They lie like crazy when they say ABS does not interfere with your service brakes.
I use the vacuum method where all the fluid goes into jar, put the rear of the vehicle up on oil changing ramps, front I can get at with the wheels turned outward. But first remove the bleeder and coat with Permatex non-hardening gasket maker, if you don't do this, will be sucking air, very little fluid drips out. Do one wheel at a time, starting with the furthest, and pump until the fluid comes out clean with a clear plastic hose.
And you want to make darn sure that reservoir is full, if not, will get air in that ABS pump and really have problems.