Itinerant Air-Cooled

Howdy all,
I’m new here, but I had the pleasure of meeting and doing a work day with Colin in Pensacola, back in December 2015, during my first cross country trip in my’69 Westy, affectionately known as Pearl. Since then, I’ve been much less intimidated by the prospects of working on my vehicle myself, and have taken on many different projects.

Currently I’m looking to replace a leaky seal behind the main pulley. I paid someone else to do this on a previous engine, but would like to do it myself this time! I ordered the seal from Bus Depot, and rented a pulley puller tool from Auto Zone. Trouble is, I’m not finding much information on how to do this, short of cracking the block, which is not in the plan! Any input or guidance would be much appreciated!

Hello. I love the mountains!

Front main seal is behind the flywheel. Is that the one you're thinking of - or are you looking at a leak at the pulley? If it's the pulley then you are at the mercy of crankcase pressure and the threads on the pulley itself. There is no seal here normally. You might have had an after market 'sand seal' installed before?

Yeah, sand seal, behind the pulley. I’m told that’s called the front because the aircooled VW engine is backwards.
So if I put that seal in, do I need an after market pulley too?

By the way, I meant to mention that it’s a stock 1600.
I looked all over YouTube and searched here and the Samba forum boards, but found little to no information on this.

You are actually referring to the rear seal behind the pulley. Someone might correct me but there is no real seal there unless you put a sand seal in there. I would suggest getting the correct stock pulley or one with the oil slinging grooves in it and install that one. It will most likely solve your problem. All you need is a pulley puller.

I have the stock pulley now, and it spews oil like crazy. I suspect I have had the belt on too tight, and it has caused wear in the case, from what I understand, so I think I’m beyond the point of just needing a new pulley...

I appreciate any help as I feel a bit over my head in these waters!

Pearl the Bus wrote: ↑

Wed Jul 22, 2020 10:51 am

I have the stock pulley now, and it spews oil like crazy. I suspect I have had the belt on too tight, and it has caused wear in the case, from what I understand, so I think I’m beyond the point of just needing a new pulley...

I appreciate any help as I feel a bit over my head in these waters!

Slow down here! A tight belt does not necessary destroy the case when there is no seal there. Stock pulleys do not have a seal! They merely sling the oil back into the case by virtue of grooves spiraled into the pulley hub.

A leak out the back of a stock upright engine suggests many possible causes. There are gallery plugs back there, check your Tom Wilson book.
Too much blowby from worn rings, for example. A clogged or pinched breather hose from the oil filler breather to the air cleaner.

Start your inquiry with a good cleaning around the case and pulley. Get the engine warmed up at idle and look for a leak while sitting there idling. Check those gallery plugs.
Take the oil filler cap off and rev the engine smartly while checking for a blast of vapor/oil out of the filler cap opening. Now check under the engine, oil leak occur when you revved the engine? Check those gallery plugs.

Leak actually narrowed down to the case directly at the bottom pulley hole?
You might even has a clogged drain passage inside the pulley bore (at the bottom) that can stop your leak with one good blast of GumOut into the drain hole.
Colin

Okay, I haven’t been driving much lately, so I apologize for the delayed response. I cleaned up the engine, particularly around the pulley area, as that’s clearly where the oil mess is centered. I changed the hose from the oil bath to the oil filler, just because it was pretty old and nasty looking. The oil filler has been lose for quite some time now, and I had no idea that this could cause leaking elsewhere, so I tightened it up and replaced the o ring.
When I tried finding the oil leak at idle the other day, it showed no signs, and today I took it for a drive up into the mountains, and it’s still looking good! I thought that it might need to be under load to leak, but I pushed her pretty good today and there’s no sign of a leak!
What a relief
Thanks VW guru!

So does this mean that it was leaking because the engine was essentially ‘breathing’ IN the oil filler and OUT behind the pulley?!?

Pearl the Bus wrote: ↑

Sun Jul 26, 2020 10:44 pm

So does this mean that it was leaking because the engine was essentially ‘breathing’ IN the oil filler and OUT behind the pulley?!?

The engine does not "breathe" like that. Imagine the pistons blasting back and forth, there is a riot of air pressure/vacuum in the crankcase. The only actuall escape of air from the case comes exclusively from combustion gases escaping past the rings.
Colin