Review on ACDelco 18M2431 Professional Cylinder Assembly by Jon Dugan

I bought this master cylinder for an 04 Elantra. For some reason the Elantra seems to have a sticky front right brake issue over time. We had a 2002 Elantra and a 2004 Elantra and both cars showed the same thing. The right front pad wears excessively and may damage the rotor. In both cases, I've tried bleeding (in the method suggested by Hyundai), swapping out brake parts like pins, and even swapping out the calipers. None of these things worked, and after digging further I found an article with information that a bad master cylinder can cause some of these failures. Another component to consider are the proportional valves located at the ends of the brake lines attached to the master cylinder. Also, don't forget the year of manufacture of your car. Apparently Hyundai has changed something in its '04 model. I can't remember if my classic part was newer or older, but you need to know the production date of your car to select the right one. Ah, the last one. You must bleed the master cylinder before installation. Otherwise you're pumping a lot of air into the braking system and spending quite a bit of unnecessary effort to bleed it. Before installation, the master cylinder can be pumped into a vise.