LEAK in a 1998 GMC Sierra 2500? Please Help!?

[Stephen]

I have a 1998 Gmc Sierra 2500 and theirs a small leak coming some where from the engine underneath. I have not yet located the leak but it is a small leak...i really hope its not the rear seal but if anyone knows about these trucks and think they know whats causing this to leak i would really appreciate it, because i am a new owne of this truck so dont know a whole lot about it yet? it does have the 350 vortec in it also? so thank you and please help if you u have an idea what it could possibly be thanks

 

[Molson02536]

The oil filter adapters on these have a rubber o ring seal on the top where they seal against the block. It is pretty common for these o rings to get hard and brittle and to blow out or split and leak real bad. I have seen motors destroyed in just 4 or 5 miles of driving when they go bad because they can leak so much oil so fast as it is under pressure at that location. You may also want to be sure the oil pressure sending unit itself is not leaking. Also pretty common on them. Not hard to repair. Just buy an new o ring and gasket for the adapter, remove the filter, if it has cooler lines, unhook them, then remove the adapter. Some of them have 2 bolts inside of them that are covered by the filter. Some of them you need to remove the threaded shaft that the filter screws onto. Some have an Allen shaped hole in them to install a tool, some have torque shaped and some have a flat area toward the top of the threaded pipe to get a wrench on. Just remove the adapter, clean the old o ring and gasket off, install new parts and assemble. I like to use a little Vaseline to hold the o ring in place while going back together with it. But fix it fast, don't try to drive it or it may cost you a motor. If you do not understand any part of this, drop me a note and I will try to clarify.

Good luck and keep us posted.