740gl water pump

how does a water pump on a B230F engine work? .It does not look like a
normal impeller on other cars when viewed through the hose connection
with a mirror. is it a gear pump?(can't imagine it being one)

 

Same as any other.

Here's some pumps from one our shop's suppliers, showing 4 brands that fit
my '90. Different designs for the impellers (some have exposed vanes, some
covered by a "disk" on the block side, but still the standard design... suck it in
through the big hose, blow it out the smaller ports.

http://i46.tinypic.com/34yqis6.jpg

 

Looks like I will have to pull it off, Can not see the vanes through the
hose port like I expected to.

 

What water pump can you see the vanes through the hose port? The big
hose is the intake port to the pump, water is plumbed through a
passageway to the center of the impeller and then ejected through the
back into the engine block and through the top into the cylinder head.

There's not much to go wrong with the vanes though, the only problem
I've ever had was when a salvage yard radiator had a pebble in it that
made it into the pump. Usually the bearings and/or shaft seal fail.