Had that problem with mine at one point. Not sure of any aftermarket choices but mine were clogged with mud/wax/ whatever. A needle does wonders of opening them back up if yours arent spraying effectively.
01 TJ. Dana 30/44 4:88's, 4.0 5 speed, 38.5x15 Boggers on 15x10 Streetlocks, CAI, B&M short throw, Neoprene Covers, 4" RC, 3" BL, too much to list and building. >..<