I have acquired a 1988 5 speed 240 that was badly neglected by the previous owner. I fixed some things that required it, and am now confronted with a new issue. I suspected the timing was off. ( It wasnt. ), but I changed the belt on principle. While doing that, I noticed A LOT of corrosion on the water pump and the hose connection. Thought I would change it on principle also. I had a difficult time removing it as it was corroded in place. It had a pump of unknown origin so I put a used but functional Hepu pump on, no gasket sealer. Leaked like a sieve when I filled the radiator. Cussed a while, removed fan, belts etc., applied gasket sealer, re installed. Leaked just as bad. Removed pump, put new gasket, ( thicker one ), sealer, and instead, installed a used but functional Volvo pump. LEAKED LIKE A SIEVE. I am beginning to wonder if PO had this issue and put some liquid sealer of some kind in the radiator. This is the 7th. or eight pump I have put on a 240, never had a problem before. I tightened the bolts until I feared they would strip.

Has anyone ever had an issue with pump installation leak??? I am stumped.

Where exactly is the pump leaking? From behind where it is bolted to the block?
From above where it mates wih the head? From behind where the heater return pipe is pushed into that outlet on the pump?

Did you polish the mating surface on the block before installing the replacement pump?
Did you, using a small mirror, check for and clean/polish the matting surface on the head; where that "mushroom" seal at the top of the pump meets the head?

FYI, using sealant on the WP gasket opens you up to the following risk: Some of that sealant gets squeezed out to the edges and may drop off and get circulated around and end up in the radiator blocking the channels. (ask me how I know this!)

CB, Thank you for your response. A friend of mine came over yesterday and we were discussing my issue. He crawled under the car with a flashlight and easily found the problem. The used Volvo pump was leaking at the rubber seal found at the six o'clock position on the water pump. We looked at the Hepu pump, and it had a leak at the same position! We surmised that a new pump in a box may have an unlimited life span, and perhaps so with a pump in use. ( as other boarders have stated.) It seems that an old pump, though non leaking, after being left dry for years, is not a viable backup to put in your trunk. Not in the case of these two pumps anyway.
Thanks for the tip on gasket sealer though.
PS Boy do I feel dumb.

"The used Volvo pump was leaking at the rubber seal found at the six o'clock position on the water pump. We looked at the Hepu pump, and it had a leak at the same position!"

Curious about the rubber seal at six o'clock.

Years ago my brother in law described something like that on a 940 water pump. On the phone. I had no idea until I saw the old part. It had some sort of black plastic plug on the bottom where all of my 240-experience places the weep hole for the cavity between the bearings.
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Art Benstein near Baltimore

“Prefer knowledge to wealth, for the one is transitory, the other perpetual.” -Socrates

Yes, the Volvo pump had a rubber thingy that I pulled off with my fingers. The Hepu pump had a metal plug that was visibly deformed. Maybe by being abused while in storage. As I remember, these were both good pumps that I had replaced on principle and saved to put in the trunk for emergencies. My guess is that a working pump that has been "cured" by heat, water, and anti-freeze can not be put on a shelf to be used later. Of course, a new one can. Any thoughts on why they leaked?

The only way to know for sure is to take it apart.

Over the years I have done this on half a dozen hepu volvo pumps.

Most of the time it was the rubber bellow (polymer ?) seal between the bearing and the mechanical seal that ruptured. I saw it once so tender I could tear it in pieces with 4 fingers. That was on the last surgery and it got me realy disappointed about hepu.

Some time it was the mechanical seal itsef that broke, or came loose from the bellow. Other time the bearing was shot.

The mechanical seal is carbon like washer that contact perfectly the impeller.

Unless in an emergency it is better to use a new pump.

Of course I always keep spares parts in the trunk like: ALL USED - water pump, alternator, fuel pump, distributor cap and dizzy, spark plugs and wires, ignition coil, small light bulbs etc.

I take a chance that it will work when needed, crossing my fingers here.

Though I have nothing against used parts, ( I would rather have a junk yard Bosch alternator than a new auto zone one ) , Theis experience made me swear off saving used water pumps. Sorry to hear Hepu is not a good one. Bought two today.

"Sorry to hear Hepu is not a good one. Bought two today."

Don't be sorry, I myself would buy( and have bought) Hepu water pump again.

Only thing that puzzle me is: have they had a new bellow supplyer at that time?

is it because I used orange Prestone coolant ?

I know people here want to see the green coolant in the volvo system. Somehow I found the orange stuff keep less fat (deposit) in the cooling system. In winter I found it is noticeably better heat with orange Prestone.

Have not had anything negative using orange Prestone 15 years on this 1982 with original heater core at 300k miles except this hepu bellow failure.

Crossing my fingers again ...

Forgot to mention,

I replace coolant always before the posted 5 years limit printed on the jug.

Hepu has been my choice for nearly 20 years, and I've certainly replaced a number of them. Difference is, I've never once had a "failed" pump, if you don't count the Airtex pump I bought in '99 which pumped insufficient volume at idle speeds. Never have I had coolant leaking from the weep hole. Never experienced a bearing failure resulting in shaft wobble.



The pump on the left is one of the very first Volvo pumps I changed. It wouldn't circulate coolant at idle from brand new. An emergency purchase at a local auto parts place. Fixed with the one on the right, and yes, I learned to not use RTV on the seals.

The reason for replacing the pumps in every other case was corrosion at a sealing surface, combined with age. Sometimes that just added up to balancing the cost of a replacement part with the risk and time to clean up the old one. And for some silly reason, I kept most of the used ones until I needed the shelf space. No, not in the trunk.

One day I needed a pump and found I had two of the other kind on the shelf instead of one of each (B21/23 vs B230). Here's the story behind that.
http://cleanflametrap.com/wasserpumpen.html

Bottom line is, the Hepu I bought 20 years ago isn't exactly the same as the one I restocked the shelf with last year.
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Art Benstein near Baltimore

Expert: An "ex" is a has-been and a "spurt" is a little drip under pressure.

Hepu is also my choice because they have the similar impeller as the Volvo pump.

I had once replaced a pump with one that had a sheet metal stamped formed impeller. I think it is similar experience you had. That gave no performance at idle for the heater in winter.

Your practice of replacing coolant pump with a new one when there is problem in that area and you feel it has enough mileage is the optimum waranty that you don't have a problem on the road. No need for a spare in the trunk as you say.

I actually keep the belts not thighter that specification. Just keep these from making noise. That is good no doubt for the pump bearing.


I take a pump out of service when there is some play on a worn bearing. Or a leak at the mushroom seal if there is a lot of mileage on the pump.

A rubber bellow failure is the worst because it is most of the time a major coolant leak. On the road ...

Good story and info on the cleanflametrap site.

Many thanks.

There is a lot of talk about cast impellers vs stamped impellers. Since original pumps Volvo installed at the factory were from a supplier who used cast impellers, I think folks believe that is ipso facto a better design than any pump with a stamped impeller. I'm skeptical. Especially, noting, Volvo began supplying their pumps with stamped impellers in the blue box you would obtain from the dealer parts department. Funny how prejudices form in our minds.
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Art Benstein near Baltimore

Don't be irreplaceable. If you can't be replaced, you can't be promoted.