having a 1/2" smc valve problem...... HELP

now the story starts here, i have this friend who owns a 97 dime, bagged by a hack and ive been called in to fix it. for about 6 months on and off ive fixed this and that and now the front fill valve is far beyond pissing me off. simple front/back system, 4 valves. ive replaced the diaphram 3 times with 3 different diaphrams and it still leaks up, slowly but it does. ive cleaned the inside of the valve multiple times and there are absolutly nothing in it that would hold the diaphram open. there are no cracks in the housing and i have ran out of options. anyone have any answers? help a guy out, im dying here . . . . . . .

I have the same problem but I am running GC's. I am in the same boat. JIMMY

Try swapping the spring inside with the rear fill valve.

if the problem then goes to the rear you know it maybe the spring, I would start swapping parts with the rear fill to pin-point the problem.

Sounds like the spring that holds it closed. Just had this prob on my Herions on my daily. Not sure about the inside of a smc but they all pretty similar designs. My spring was broken but the get weak and would cause the slow leak up. Pull the top cover off and it should be right there. Dont even hafta take the valve loose to change it. Hope this helps.

if all else fails....$50 for a new valve. Not to sound like a tool or anything, but if you've messed with it 3 times and on 3 different occasions, look at the time you've put in it, and how much is your time worth? Personally at this point, I would have been so mad with it, I'd have just replaced it. If you can fix it great, but how much more time will it take to chance down bugs?

I had 4 GC's that did this... I pulled the springs out and stretched them a little to try to make it hold better. it didn't work so I replaced them this week and it's ok now.