TheSamba.com :: View topic

Sat Aug 09, 2003 6:26 pm

Hello,

I have a 1970 Bus with a 1971 engine. Bought it about two weeks ago.

I had a VW shop go over it before I bought it, and they noticed there was oil leaking around the oil pressure sender, so they replaced it.

I noticed oil dripping from the sender's nut today, and when I took it off, I was suprised at the rough seam on the case, running right across where the sender seats.

Here is a photo of what I'm talking about:

http://members.cox.net/jonwade/oil-sensor-hole.jpg

Is this normal? Should I carefully file the raised part away? Also, what's up with the case's paint flaking? Is that paint factory spec'ed? It seems to just rub off with a rag.

I am loving this bus, and he's already given me some good miles of enjoyment. I'm in Tucson, and using Castrol straight 40 weight oil, based on the repair shops recommendations.

Thanks for any help,
Jon Wade
jonwade@cox
http://members.cox.net/jonwade/bus/

Sat Aug 09, 2003 7:58 pm

The paint is definitely something not factory, it is someone elses idea that didn't work since it is flaking off. I personally don't like paint on the case, since it can soak up oil leaks and hide them and it just looks crappy. There are differing opinions on whether or not the paint allows the case to cool as well, I prefer no paint. On the filing I wouldn't unless you really can make sure that no filings get in the hole and plug up your oil galleys. When the sensor was in the case was it flush with the case? if so, someone the hole for the sensor has been stretched out from the person before you overtightening the sensor, they should not be overtightened. Don't put teflon tape on the sensor threads either that will not make a good contact for the sensor itself. As far as the oil leak you can either deal with it until the next rebuild or have someone "carefully" have it filled and rethread or helicoiled??!! I would just keep it wiped up, for now. Good luck with the bus

Sun Aug 10, 2003 5:50 pm

Get yourself a pipe thread plug the same size as the oil sender unit and thread it in as far as it will go. Brute strength is not needed here. Then take a small, fine file and carefully file the seam off. The plug will keep any filings from entering the oil passagway. The guy above may be right about someone threading in the sender, in the past, using too much force. this would in turn, deepen the threads, so you must take some material off the surface of the boss in order for the sender to go deep enough to seal, but not bottom out on the case. I always use a little teflon PASTE (not tape) on the threads. The high point of the threads will still ground completing your circuit.

Sun Aug 10, 2003 5:51 pm

Also, examine the area VERY closely to see that someone has not overtightened the sender and cracked the boss. :shock:

Sun Aug 21, 2005 7:02 pm

Ok what can you do once the boss is cracked as is in my case .
The case is split at the moment i plan to drill and tap for full flow oiling .
And a really dumb question , this is an aftermarket universal case how can I tell if it is aluminum or mag ?
Thanks , Steve

Sun Aug 21, 2005 7:45 pm

vw made 2 case materials AS41 (soft) and AS21 hard (hard), thats all. careful with the assumptions about buying a plug for that sensor hole. hardware stores dont sell metric tapered thread fittings. you could REALLY mess it up.

perhaps it wasnt made clear- the factory left a seam there cuz they didnt use that surface as a sealing/mating surface. the seal is provided by tapering both the sensors thread diameter and the hole diameter is tapered as well- this is what you would call an interference fit of the threads. before the case became stretched/cracked the sensor would have tightened up before it ever reached the seam

Mon Aug 22, 2005 2:33 am

Lots of places have sold unsuspecting owners sensors with 1/8" National pipe threads, similar in appearance, but not the same as the factory's metric threads. Figure out what threads are in there before you re-thread or chase the threads.

Hopefully the metric threads can still be salvaged. If they've been cut too deep for the taper of the sender to seal, a brass extender of the proper thread might help out, along with the aforementioned sealer.

Either sensor will work electrically; the right one will also seal! Best of luck.

J.R.
68 Westy