First you can try bleeding or
Check for small leaks or sweating. Look inside the cab where the peddle connects to the master on the firewall if carpeted pull back and see if there is any fluid.
Crawl underneath and look at the slave cylinder if internal look for drops on the bottom if the bell housing.
If you find no leaks you may just have a worn out master bypassing internally.
89 2.5 TBI, 4" RC lift, 1" Booms, SYE, Adams Driveshafts front and rear, Ford 8.8 with 4:88s, BFG 33X12.50X15, and a ton of other stuff.
AF Jeep Club Tail Number 184