Water pump replacement

paul4be · May 12th, 2006, 07:20

Is there anything particular I should know about when replacing a water pump on a B21A, or is it really as easy as the manual makes it sound?

It has a very slight leak from the pump to head seal, so will be getting swapped in the next week or so.

Many thanks.
Paul.

Andrew (UK) · May 12th, 2006, 09:31

The pump to the head seal is the difficult bit about replacing the water pump. If that is what is leaking then just get a seal set unless you really want to do the whole pump or it is very old, the amount of work is the same though.
It is really easy to get that top seal wrong when re-installing the pump, it also makes getting the bolts to line up with their holes quite hard. You really do have to lever up on the pump to make it happen. You may get two different versions of that top seal to use with different thickness head gaskets, don't try and use the bigger one with a normal (thin) head gasket as it will never line up the bolt holes then.
That top seal can fail if it gets soaked in oil from a leaking camshaft oil seal or valve cover gasket. So make sure you don't have oil leaks in that area or you may be doing the job again after a while. The camshaft oil seal can leak if your PCV system is blocked somehwhere (flame trap, oil trap, manifold nipple or connecting hoses - check them all).

Andrew

Mike_Brace · May 13th, 2006, 22:11

There is a top hat seal or a tubular seal available - the top hat works fine on pump replacement whilst the tubular one is only ok when replacing head. It is important to clean out the recess it fits into well. Also you can get problems if the pipe running down the side of the block is corroded.

Mike

Clifford Pope · May 21st, 2006, 19:54

I'd also add:
make sure you get the right gasket set - pumps and main gaskets are not all the same for different models.
Apart from the levering trick to compress the pump/block seal, the pump to heater pipe rubber sleeve can be tricky. Put it partly on the pipe, then partly insert the unexpanded portion into the back of the pump, then press it back so that it slides neatly over the pipe and into the recess in the pump at the same time. Some people favour some sealant. If you get the seal too far onto the pipe first, it can catch in the pump recess and turn up the edge so that it doesn't sit properly. I think some pumps have a flange with a nut and bolt as well.

I certainly concure with the warning about leaking oil getting onto the upper seal. Mine blew out once without warning, leading to total water loss within seconds. Fortunately I was going slowly so saw the steam and was able to turn off instantly. The temperature gauge never got a chance to register.

May 12th, 2006, 07:20	#1
paul4be Junior Member Last Online: Apr 16th, 2008 21:24 Join Date: Dec 2005 Location: North Yorkshire	Water pump replacement Is there anything particular I should know about when replacing a water pump on a B21A, or is it really as easy as the manual makes it sound? It has a very slight leak from the pump to head seal, so will be getting swapped in the next week or so. Many thanks. Paul.

May 13th, 2006, 22:11	#3
Mike_Brace Former contributor Last Online: May 15th, 2024 09:52 Join Date: Dec 2004 Location: Rhosgoch, Anglesey	There is a top hat seal or a tubular seal available - the top hat works fine on pump replacement whilst the tubular one is only ok when replacing head. It is important to clean out the recess it fits into well. Also you can get problems if the pipe running down the side of the block is corroded. Mike __________________ A Volvo is for life not just for Christmas!

May 12th, 2006, 09:31	#2
Andrew (UK) VOC Member Last Online: Dec 3rd, 2021 08:39 Join Date: Jan 1970 Location: Sutton, near Ely	The pump to the head seal is the difficult bit about replacing the water pump. If that is what is leaking then just get a seal set unless you really want to do the whole pump or it is very old, the amount of work is the same though. It is really easy to get that top seal wrong when re-installing the pump, it also makes getting the bolts to line up with their holes quite hard. You really do have to lever up on the pump to make it happen. You may get two different versions of that top seal to use with different thickness head gaskets, don't try and use the bigger one with a normal (thin) head gasket as it will never line up the bolt holes then. That top seal can fail if it gets soaked in oil from a leaking camshaft oil seal or valve cover gasket. So make sure you don't have oil leaks in that area or you may be doing the job again after a while. The camshaft oil seal can leak if your PCV system is blocked somehwhere (flame trap, oil trap, manifold nipple or connecting hoses - check them all). Andrew

May 21st, 2006, 19:54	#4
Clifford Pope Not an expert but ... Last Online: Yesterday 15:38 Join Date: Dec 2001 Location: Boncath	I'd also add: make sure you get the right gasket set - pumps and main gaskets are not all the same for different models. Apart from the levering trick to compress the pump/block seal, the pump to heater pipe rubber sleeve can be tricky. Put it partly on the pipe, then partly insert the unexpanded portion into the back of the pump, then press it back so that it slides neatly over the pipe and into the recess in the pump at the same time. Some people favour some sealant. If you get the seal too far onto the pipe first, it can catch in the pump recess and turn up the edge so that it doesn't sit properly. I think some pumps have a flange with a nut and bolt as well. I certainly concure with the warning about leaking oil getting onto the upper seal. Mine blew out once without warning, leading to total water loss within seconds. Fortunately I was going slowly so saw the steam and was able to turn off instantly. The temperature gauge never got a chance to register.

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