Date: Mon, 1 Nov 1999 20:38:00 -0800
Reply-To: Davidson <wdavidson@THEGRID.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Davidson <wdavidson@THEGRID.NET>
Subject: Installing VDO Oil Pressure Sender
Content-Type: text/plain; charset="iso-8859-1"
Volks,
I just finished installing the VDO Dual Oil Pressure Sender on my 90 Westy
Syncro.
It was a real pain in the butt to get a nice installation in such a tight
place, and I thought I would share some of what I came up with.
The stock .3 Bar sender is located behind the engine tin that covers the
push rod tubes on the driver's side (You have to gut under the van). It
simply screws into the engine block. However, it is in a very tight spot and
the after market .5 Bar VDO Oil Senders will not fit into that spot. After
reading the excellent article by Karl Bloss at www.vanagon.com and after
consulting the List Archives and after reading the instructions at the Bus
Boys site at http://www.bus-boys.com/bbvdo.htm I realized there were two
options to connect the VDO sender to the engine block and I didn't like
either one of them.
The option described by Karl and the Bus Boys is to purchase the $25+ rubber
hose and run it to the outside of the engine tin and mount the sender there.
Unfortunately, the hose is 12 inches and it turns out that is a very awkward
length because no matter what way you route the hose the sender seems to end
up near the exhaust pipes. I really don't like all the bends in the hose or
the fact that it is so near the heat of the exhaust pipes... bends and heat
are not good for rubber over time.
(I wouldn't mind the excessive price for a piece of rubber that looks a lot
like the $4.00 hose that goes on the end of a greese gun if it made a nice
installation, but it doesn't.)
The option described by several in the List Archives is to use 1/8 inch
brass pipe... thread about a two inch piece into the engine block and add
fittings to route the pipe to the outside of the engine tin. I really don't
like this method because of the torque (and vibration) that will be
transmitted by the pipe to its attachment at the engine block. It would be
really bad to blow out the threaded opening in the engine block!!
So here's what I came up with:
Mark the engine tin just above the arch between the two lower bolts in the
middle of the fore/aft curve , straight out and down from the stock sender
hole. I drilled and enlarged it with a round file such that a 5/8 I.D.
rubber grommet will fit snuggly, leaving only about 3/8 or 1/2 of a inch of
metal between the grommet and the edge of the engine tin. The idea is that a
short hose will thread into the stock sender hole, come straight out and
angle down at about a 45 degree angle, go through the grommet, attach an
elbow pointed toward the oil filter, and attach the VDO sender to the elbow,
and attach the VDO sender to the engine tin with a 'P' shaped metal hose
strap and a sheet metal screw (Regardless of what anyone says go ahead and
use Teflon tape on the threads of the fittings... rubber hose will not
ground the sender! If the strap has padding or insulation strip it off, the
metal strap makes the ground connection for the Sender if you are using
rubber hose). This puts the VDO sender just forward of the oil filter,
nestled in the curve of the engine tin that runs fore and aft.
I went down to "Hose & Fittings, etc." in Reno (I'm sure most large towns
have such a place... or contact a place that services construction
equipment). I found out I could get a small rubber hose made for about $5.00
or a braided stainless steel with Teflon lining hose for about $9.00. I
chose the stainless steel hose because it will withstand heat up to 2,000
degrees and should not deteriorate under engine heat conditions... (also it
turns out that the nut on the rubber hose was smaller than the diameter of
the hose so it would be difficult to reach into the small stock sender spot
with a wrench at extreme angle and get a bit on the nut.... the stainless
steel hose is smaller diameter than the nut and makes it much easier to get
a wrench on it). After a couple of mistakes I found that the perfect length
for the hose is 3 5/8 inches.... for the ss hose, if they cut it to 3 1/2
inches (end of fitting to end of fitting) it will grow to 3 5/8 inches when
they crimp the collars of the fittings to the ss hose.
Metric fittings are difficult to find, but it turns out that 1/8 inch pipe
threads work great on both the sender and the stock sender hole even though
those threads are 11 mm. I got my hose made up with a 1/8 inch male pipe
thread fitting on one end and a 1/4 inch tapered female fitting (like
tapered gas fittings) on the other end. I got an elbow with 1/4 inch tapered
male on one end and 1/8 inch female pipe thread on the other end. The
tapered fitting works great in that you can install the engine tin with the
hose through the rubber grommet and add the sender with the elbow attached
last such that you can choose the angle you want it to end up at... with
pipe threads once it is tight that is the angle your sender will be mounted
at! I also got my 'P' shaped hose strap at the same shop. (If you want to
use the VDO single sender instead of the dual sender you can use a T in
place of the elbow above such that the VDO sender is at one end of the T and
the original stock .3 Bar sender is at the other end of the T)
Now if you don't like the idea of using 1/8 metal pipe threads on your 11 mm
stock sender hole threads and your newly purchased VDO sender threads
consider this:
I order the Pressure Adapter Hose Kit put out by VDO. It came in a VDO
package, but the hose was labeled with an American hose manufacturer and
both fittings had American size nuts and threads (same as I recommended
above). In addition, the American to metric adapter fitting that comes with
the VDO kit does not fit the 11 mm sender threads any better than the 1/8
pipe thread elbow described above and the nut is sized for an American
wrench! Seems that VDO is making a bunch on a hose and fittings and strap
you can buy for about $8.00.
I like my installation better that the others mentioned above. It is
cheaper, stronger, there are less bends than the $25+ rubber hose kit. Also
my hose doesn't touch any hot surfaces and the sender is near the oil filter
away from the hot exhaust pipes. And I like it better than using rigid pipe
which with enough torque could damage the threads in the stock sender hole.
After calling around to several of the vendors that have been mentioned on
the list I finally bought the sender and gauge from Bus Boys 1-800-792-2697
who had good prices and better advice and service than the others... (Yes,
that's right Bus Boys! Despite all the negative vibes on the list they were
a pleasure to deal with. I talked to Walter and he is giving list members
10% off.) I guess they have a new/better owner.
Good Luck with your VDO Oil Pressure Sender!
Bill
90 Westy Syncro