dark_waters

Hi there everyone, here we go - first time to this forum and my first post.

I have a 1981 blazer with a 305.
After some extensive bodywork restoration over the past 18 months, i've got her back on the road. Since it was last run (18 months ago) its developed a major oil leak from the top of the engine, at the back (around the intake manifold)

I've got the inlet manifold off, and im doing the headgaskets,exhaust gaskets etc etcat the same time. I suspect the leak was from the intake manifold gasket as the olst owner bodged it all up with instant gasket.

However I have noticed that the oil pressure switch (near the distributor cap) revolves completely around in the block. The switch unit is tight on the shaft out of the block, but the whole sharft into the block revolves, it doesnt seem to tighten...is this normal or do I have another problem?

Ideally want to check this out before I put it all back together. Any help would be greatly appreciated.

Kind regards,
Rob.

BrianE

sounds like the threads are stripped you need to get the tube and switch out and rethread the hole. It is pipe thread so you can go a larger size and adapt the tube down to the oil switch size. the oil tube must be tite and use pipe sealant this is most likely the source of your leak. On the Intake manafold I use High heat rtv silicone on the ends. BUT after you put it all back together let it dry overnight the silicone needs time to setup a lot of people make that mistake and end up with a leak.

dark_waters

Thanks for the advise, replaced the union that screws into the block, engine is back together, no oil leaks!!