12ht Vacuum pump operation (1 Viewer)

[Silveredition]

I am hoping someone can show me how the oil feed for a 12ht vacuum pump works...
I have had my 12ht rebuilt, but the vacuum pump isn’t working as it should (heavy clutch pedal, brake light on and no brakes at low revs etc). I bought a new alternator/vac pump and new genuine inlet / return hoses ($$$) but there was no difference when fitted..
The inlet / return holes on the block are at the same height, and no oil comes out of either when the hoses are off (engine off). How does it pump oil if they are both above oil height??
Brakes / clutch etc were working perfectly prior the the rebuild...

 

[ceylonfj40nut]

Your oil pump works when the engine is on. Oil pump is located behind timing cover on front of engine and is gear driven of the crankshaft. Oil pressure from pump gets it to the vac pump housing. Vac pump rotation gets oil back to block. I would disconnect oil discharge hos from vac pump, place hose in a bottle and start engine for a brief period to see if oil flows. If not oil inlet side to vac pump is blocked.

If oil flows check you vac hose lines from vac tank to brake booster and other locations. You must have a leak in the lines somewhere.