Can the modulator valve be resealed? I have looked all over and don't see a breakdown for just the valve. Mine is leaking the the leading edge. It looks like I could just unscrew the bolt in the end, but I don't want to take it apart to realize I just ruined it.

I have looked through the sticky.

 

Any ideas?

 

Uhhh, modulator valve? Got a picture you can post?

 

https://www.dieseltruckresource.com/...d.php?t=231863
Third picture down, part 37,pressure modulation valve.

 

Looks like the KSB to me. There's one o-ring behind it. Remove the 2 torx bolts and the hard line coming into the top of it and replace the o-ring. The torx bolts are kinda tight and can give you a hard time when trying to remove them. They're prone to stripping out so you'll have to be extra cautious that the bit is in the head straight. I used a small pick to get any debris out of the bolt head to allow the bit to sit as deep as possible. Also, I'd suggest pulling the vacuum/powersteering pump to give you additional room 'cause it will become an interference with whatever tool you decide to use to remove the bolts. Unplug the oil pressure sensor, otherwise the pump can't move.

 

KSB it is. Its been a while since I messed with this truck. The leak isnt coming from the back side, I replaced that gasket when I had it out the last time. It is leaking from the leading edge, where the exposed hex head is, pointing at the front of the truck.

Thanks for your info.

 

You should be able to just pull that plug and replace the o-ring. Just keep a catch pan ready in case there are any shims and a spring behind it.