[Vwdiesel] more vacuum pump

[sandy cameron]

On 12/15/2012 4:23 PM, Scott Alexander wrote:
> So I got a rotary pump.  It came with some directions that seem to have been translated poorly talking about an oil feed.  In the hopes that it all came down to "make sure that the tab inside the block fits into the slot inside the pump", I assembled it all.  I blocked off the hose from the crankcase to the old pump by shoving a bolt in the hose and tightening down the hose clamp.  Otherwise, I assembled it as I would the old pump.  When completed, I took a quick spin around the parking lot.  The good part is that I now have assist on the brakes again.
>
> The bad part is that, after a short time, the oil light comes on.  Normally, it comes on with the alternator light when I turn the key to "on".  They both remain on until the alternator starts producing a reasonable voltage and they both go off.  That is still happening.  It's just that a short time later the oil light comes back on.
>
> Any ideas as to what I messed up this time?
>
A few thoughts. How stiff did the vacuum pump feel when you rotated it? 
It is driven by the intermediate shaft, which is FRICTION-DRIVEN by the 
smooth BACK of the timing belt. If the pump is stiff, it may cause the 
belt to skid on the smooth pulley.

Did you replace the big O-ring under the vacuum pump? perhaps it is 
being forced down into the slot on the oil pump shaft, binding and 
making it difficult to turn.

I think the tab and slot are offset a bit to one side (used to drive the 
distributor on the gassers) .
There's a 50% chance if there's space, if it's worn, to insert it the 
wrong way and bind it.

Because of the friction drive, make sure everything is free of sticking 
or stiffness, or you may loose oil pressure.

Sandy