The jw case i am usuing has the bigger holes in the case 3/8 inch for the pro brake and i am usuing the full tree brake and it is usuing a 1/4 inch feed out to feed the case. He told me the stock case uses a smaller hole like the one in the full tree brake and that is why i had no problem with the brake holding when i was usuing the stock case ....i have all the problems since i changed to the jw case......so does this make sense by him making the hole bigger in the valve body on my full tree brake to match the same size as the case, it will pressure up and fill the the reverse port quicker..thus holding the trnasbrake....i have 220 psi spring in the tranny and when in gear it goes up over 230 psi and when the brake was applied the pressure didn't drop......i did not have a gauge on the reverse side though....when i put it back in i am going to warm up the tranny good as it seems to hold when it is cold and not when it is hot and put a guage on the reverse side....also i am going to blow out the cooler lines and change the filter....blowing out of the front seal is the first time i had thaT HAPPEN i think that my line from the vent to my can was kinked....i am going to replace with a braided line.......the tranny guy told me if it doesn't work this time i have to take it to someone else and he also told me he is going to charge me for this...well i have spent alot of money all year and have no results with the tranny being taken out 6 times and going to the races and only making one pass and putting it on the trailer is enough pain for me to mention pulling it in and out and all the fluid.so on.u know what i mean............so i do appreciate u replying to my problems.......and i am hoping that making the hole bigger in the transbrake valve body to match the jw case will solve the problem let me know what u think.................thanks alot