Whats your pressure set at?
1. De-gas the regulator. Replace the relief valve seat o-ring by taking a pick and pulling the old o-ring out. Replace the relief valve seat with a new one as shown in figure 1. Make sure the o-ring is flat and secure in the recess.
2. Examine the piston o-ring for damage, if it appears to be damaged remove it with a pick, then replace the o-ring by hand. Most of the time the relief valve seat is causing the leak, but sometimes it is the piston o-ring.
3. Replace the parts and cover in order shown in Figure #1, pressurize again and check for a leak.
4. If you remove the cover and see a leak at the bottom of the piston, then the leak is in the regulator seat. (All leaks are seen at the bottom of the regulator.)
5. De-gas Regulator. Remove the retaining nut with 3/8" Allen wrench. Then remove poppet guide. (See Figure #1) Insert your finger, turn assembly upside down and remove remaining pieces. Set aside as they were removed again referring to Figure #1.
6. Using a Q-tip and alcohol clean the inside of the regulator body. Then remove regulator seat, seat hose support, poppet, and spring guide.
7. Remove the filter from the spring seat and rinse the filter under hot water to remove dirt.
Clean the spring, seat and put the filter back on. Clean the spring by wiping with a cloth and alcohol.
8. Clean and inspect the poppet. Look carefully at the cone shaped area at the center of the
poppet. Look for nicks, scratches and pitting. Inspect the larger diameter end of the poppet for rub marks and burrs. If the poppet is damaged, replace it. If the poppet is all right, lubricate the larger diameter end with a small amount of Rekoil oil, spread evenly.
9. Study the valve seat cap, base and seat seal. Look for marks and cuts on the seal and ensure no dirt is trapped in the seal. Study the assembly detail #3. Remove base seat and clean internals. Replace any damaged item you may find. Refit base seal seat, seat seal and seal cap in that order ensuring they are all clean.
Maybe that will help