2004 Bolens 38 inch cut. 15.5 HP engine MTD transmission. I replaced the upper and lower drive belt on my Bolens/MTD. It starts fine. I can put it in gear but no matter how hard I push on the brake/clutch it will not come out of gear. I can put it in forward and it runs fine. I have to stop the engine to put in reverse or neutral. If I put it in reverse it will run fine but I can not pull it out of reverse without shutting off engine. I have adjusted the disc brake so it is barely engaged without pressing brake/clutch. I have also recently cleaned the transmission and replaced the grease with the MTD brand grease. Approximately 19 to 20 ounces. I can fix most issues but this has me stumped. Any help or advice will be greatly appreciated. I wonder if I just need to wear in the new belts?