'90 740 Turbo - Water pump installation probs, I got 'em bad

Hey all. Am almost halfway through installing a new water pump. Have
unbolted the old pump, but am unable to pull it loose it loose from
the metal return tube that attaches to the back of the pump. It seems
really stuck, and if I didn't know any better, I would think it was
welded on. Am i just not pulling hard enough? My Haynes manual only
covers 740s until '88 and the Chilton manual I have is effing
useless. The tube is not bolted on as shown in the Haynes manual, and
has a flat bottom to it. It just won't budge. Its not welded on, is
it? Any advice? Thanks to any and all who have pearls of wisdom for
me.

A

 

The tube is bolted in to the water pump all B230F series engines share
the same water pump look harder & you will see what you are missing on
your quest
Glenn

 

Right you are, Glenn, thanks. Its on the underside of the tube or
pipe.

Trouble is, I still cannot free the water pump. The gasket sealing
the pump and the heater pipe is 'baked' on tight. I cannot free it to
save my life. Is there some sort of solvent I could carefully use on
the gasket to free the pump? I've also tried lightly tapping the pipe
fitting, all to no avail. It seems stucker than stuck. Any advice,
fellow Volvoids? Dying to get back on the road.

 

Yes.

Soak it overnight in PB Blaster.

 

Did you remove the bolt clamping the pipe in? Beyond that it just pulls out.

 

Oh man, I wish it was just that. But yes, all bolts present and
accounted for. I know it stretches the imagination, but the gasket on
the tube has hardened, melted or aged to such a degree that it will
not let the pump go. Not sure if I can soak anything overnight, as
the pump is still very much attached to the heater tube, which is
still attached to the car. Perhaps a careful and judicious
application with a rag to catch any drips or spill might do it.
Thanks all for the advice.

 

I don't feel my imagination all that stretched; I've seen a few really old
gaskets do that. I'd also like to think the gasket wasn't "sealed" with
something unwanted.

Perhaps a judicious application of a torch or dry ice to the pipe side of
the joint? I'm hoping the aluminum will expand or contract while the metal
of the pump does not (because it isn't heating or cooling) and the bond will
shear. I've never tried that, though; the times I've come across it the
pieces were in a place I could use a plastic mallet on the side of the loose
piece to crack it.

Don't bother trying to get a chisel in the edge; it chews up the metal and
doesn't really convince the gasket to let go.

Mike

 

Remove the whole tube and work with it on the bench. It goes around the
back of the head and attaches to the heater hose.

 

Shizit, I was hoping to avoid that. I don't trust myself to remove
the exhaust manifold and the turbo. Or rather I don't trust myself to
put it back together correctly. PB Blaster has not worked. A block
of wood and a rubber mallet hasn't either. I fear I'm off to seek
(and pay for) professional help unless there's a magical 8th solution
to all this. Thanks for all the advice.

 

You shouldn't have to, IIRC it will come out from behind the manifold
without removal, you may have to remove the bracket holding the bottom
of the turbo though. Also you might try heating up the water pump until
the rubber seal melts, I'm not sure how it could hold it on so tight
though, you're *sure* you didn't miss a bolt?

 

You shouldn't have to, IIRC it will come out from behind the manifold

Ha ha, I'd say the same thing had I not removed all the bolts with my
own hands and cried tears over its being stuck with my own eyes. I'm
a bit reticent to disassemble things further, but I've already taken
various hoses off so maybe The Next Step is in order. Thank you, Mr.
Sweet. I will update.