That oil pump shaft bushing is really soft. I knocked it out with a 3/8 extension and it dented the metal where it
won't go back on the shaft unless you hit it with a die grinder. Gotta use an exact size socket for knocking that bushing
in (or out) to avoid having to do it over. Btw, the oil feed hole in the bushing goes to the left side, towards the oil filter.
I tried it the other way to see if I'd get better oil pressure, and I did, but then you get NO vacuum for the brakes LOL.
My old oil pump shaft bushing actually had some gunk in the oil passage, looks like the red paint inside the crankcase
This crud was probably helping the oil pressure, if anything, but not helping the vacuum pump pressure.
I did try the 30mm oil pump after changing the vac pump seal and the oil pump shaft bushing and there was
little difference in oil pressure. The old black vac seals looked really stretched out compared to the new green ones
but the black seals were actually still working good.
I made sure the vacuum pump feed hole was clear. This vac pump I pulled the screen out, like someone did in a vortex thread.
I don't recommend removing the little oil screen, PIA, it came out in pieces and some stay stuck in the edges.
Wish there was documentation to fully disassemble a vane pump.
Play in this vac pump was minimal and with the 36mm oil pump it does pull better vacuum.
Been driving it for a while now,
Oil pressure with the chinese 36mm pump is not great, but better.
Cold startup pressure seems better.
Fully warm gets around 40psi cruising at 65 and 15 at idle.
Never goes above 80psi cold, losing a lot of pressure somewhere (probably IM shaft)
but the lower end pressures are better and that makes me feel better.
The 36mm oil pump seems like a good patch for now.
