Engine is an 87 Turbo, with emissions removed.

I popped off the LIM to diagnose a minor coolant leak on top of the LIM, near the rear rotor. I thought it was probably the rear o-ring. The o-ring looked fine, but I went ahead and got a replacement just to cover all the bases, along with new gaskets.

When I was reinstalling the LIM, the front housing O-ring caused the gasket to break in two when I was fastening the LIM down, I hadn't even gotten to torquing it down yet. It split vertically right above and below the O-ring. I don't really want to keep breaking the stupid gaskets, so is that front O-ring even necessary? The coolant passage on the front housing is blocked off.

I'm also considering blocking off the rear and running a new line to the turbo to bypass the coolant passage altogether.

Any thoughts?

 

Ya,it will receive coolant system pressure there anyways so a good seal with the O-ring is needed.If not it will pee coolant at that area.
I had a hell of a time getting mine to stick while installing.I used a little dab of sealant and got it realllllllly tacky,installed the O-Ring then put the manifold on.

 

no you dont need an oring on the front one.