Volvo RWD 700 Forum

INDEX FOR 1/2026(CURRENT) INDEX FOR 1/2006 700 INDEX

[<<] [>>]

THREADED

THREADED EXPANDED

FLAT

PRINT ALL

MESSAGES IN THIS THREAD

REPLY TO THIS MESSAGE

SAVE

Bosch Water Pumps..... 700

posted by Will740turbo on Mon Sep 7 19:52 CST 2009
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS]

[IGNORE ALL POSTS]

last visit: Wed Oct 22 16:09 CST 2014

[RELATED]

Which sucks... Bosch water pumps or my belt tension?

90 740Ti.
I replaced the factory water pump with a new bosch unit - eight months later, it was leaking quite a bit from the weep hole.
I replaced that bad one with a factory replacement (free).
Now I can find coolant along the water pump fins. (AKA, same leak as before.)

Am I doing something wrong, like weird belt tension, or do the bosch pumps suck? I mean, I can keep getting free new water pumps, but this is RIDICULOUS. I haven't had one last two years yet.
I do notice that my alternator belt bounces, despite it being rebuilt and having its bearings replaced, might that contribute?

I do drive pretty hard sometimes, but I don't know if the bosch seals are not up to it, or it's unrelated.

If not, I guess I'm going with the hepu unit. Does anyone have any advice on this?

I'm getting VERY annoyed with constant problems with my cooling system.

Thanks,
Will
--
1990 740 Turbo, on its way to stock specs, maybe beyond

REPLY TO THIS MESSAGE

SAVE

Bosch Water Pumps..... 700

posted by Uncle Olaf on Mon Sep 7 20:44 CST 2009
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS]

[IGNORE ALL POSTS]

last visit: Mon Oct 10 19:04 CST 2011

[RELATED]

Hey Will,

Sorry to hear about your trouble. The comment about the alternator belt bouncing troubles me. Is the pulley or shaft of the alternator is bent? Or worn bushings? If the alternator pulley doesn't spin true, it could put excessive load on the water pump. If you mean the belt flutters (sort of vibrates in the middle), thats not a big deal. It could mean it needs a bit more tension, but not always. Does your water pump share the belt with the crank and the power steering? The alternator is then driven from the second groove on the water pump? Thats the configuration on my '92 740. Its possible to overdo the tension of the p/s belt. I try to set it just firm enough so it doesn't make noise under load. However, I think after replacing one pump, you'd be rather judicious setting the tension on the second. My guess is the pumps are lousy.

I have no experience with the Bosch water pumps. I did have trouble with rebuilt Bosch alternators for an old Cadillac, but I don't think Bosch actually rebuilt those. I think it was farmed out to a third party company. Perhaps thats the case with those water pumps. Not sure. I know how frustrating bad parts can be.

The OE Volvo and Hepu pumps are both good choices. I would go with the Hepu since its more reasonable, and I've heard nothing but good things about them here.

Regards, Jon 'Uncle Olaf'

REPLY TO THIS MESSAGE

SAVE

Bosch Water Pumps..... 700

posted by Will740turbo on Tue Sep 15 20:15 CST 2009
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS]

[IGNORE ALL POSTS]

last visit: Wed Oct 22 16:09 CST 2014

[RELATED]

Thanks for the response.

I'm just wondering because it'll be the third pump (and fourth time) I'll install.

I've been looking though, and I'm not seeing any more coolant on the pump itself. Is it possible for high pressure to make the pump leak like that? It wasn't condensation from the air, it's been far too warm here for that.

I'll go with the HEPU or the OEM (which is apparently not Bosch, though I was told it was) unit.

Happy Bricking
-Will
--
1990 740 Turbo, on its way to stock specs, maybe beyond

<< < > >>

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.