Water Pump Top Hole?

Got a new (not reman.) water pump for a '96 Intrepid, 3.3L engine, was surprised to see that the replacement part, a Master CP7140, had the water pump weep hole at the top. The OEM part (with an asymmetric mounting flange) has the weep hole at the bottom. First time I've seen this. Is this now common? Might the reason be to avoid paying a royalty on the original patented design?

Reply to
Woodie
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I've heard that hole referred to as either a weep hole or a hole necessary to allow pressure relief when pressing seals/bearings into the bump casting.

A hole in the top would be useless as a weep hole, but would work for the latter reason.

Reply to
Paul Hovnanian P.E.

Despite being on top, I think it could still function as a stopgap safeguard against the introduction of coolant (caused by a leaking seal) into and resulting in a catastrophic failure of a pump shaft bearing, should that even be the purpose of that hole.

I did however wrap a piece of tape over the hole, not as any type of seal, but for the sole purpose of preventing the accidental entry of foreign chemical, clogging or abrasive material dropping into the hole.

I remain curious as to whether others have observed such a possibly non-standard placement of that hole.

Reply to
Woodie

I've never seen that before. Are you sure you don't have your engine mounted upside down? :-)

Anyway, it sounds like a good idea to me - you might be able to see if the bearing is leaking. I always have to stick my hand under the bearing housing and feel for coolant. Not having to do this would suit me fine. Hopefully, nobody's paying any royalties on a weep hole. :-)

Reply to
dsi1

"dsi1" > engine, was surprised to see that the replacement part, a

Good one.

I think you mean seal.

Good point.

I was thinking any deviation from the overall design might suffice.

Reply to
Woodie

First of all you are talking about a 14 yr. old car with a part that has been around for decades. There isn't anything in the law preventing an after-market supplier from copying the original part except competence. An after-market part may vary from the original because it was copied badly.

-jim

Reply to
sjedgingN0Sp"

it's a mistake. if you look at the same part supplied by most manufacturers, they have the hole at the bottom in the normal way. that this one has it at the top is a design error by that particular manufacturer. you'll see this is you search online and look at the pics.

as to top vs. bottom location, top is a very bad idea. in fact, if you wanted to /deliberately/ mess up someone's car, you should make this mod. why? because it allows coolant to pool against the bearing seal [there are usually two sets of seals on a shaft - one for the pump, one for the bearing. the weep hole should be connected between so the inevitable seepage from coolant can run out before it accumulates], let that coolant seep in, and ruin the bearings. top location is a /very/ bad idea. but i supposes it's a great idea if you want to sell someone a new pump again in a few months.

bottom line - it's not worth trying to save a few bucks with an aftermarket component - buy the 100k mile warranteed oem that has the weep hole where it should be. don't wait - do it now before you get stranded by that piece of garbage.

Reply to
jim beam

Hole on top may even be a manufacturing mistake. Weep holes go way back to the days of rope packing type seals. They required a certain amount of leakage/weepage to ensure the seal was not too tight and overheated to completely fail as the wax melted away. In later designes, it was left there as a good way to detect leakage while allowing the coolant to drip harmlessly out preventing more rapid damage and total failure of shaft bearings. I suspect the coolant will collect around the bearings with the hole on top.

Lugnut

Reply to
lugnut

I was only hazarding a guess as to the reason it might deviate from the original design. Perhaps you're correct, although I can hardly fathom the staggering incompetence required to manufacture and continue to produce a device that poorly copied lo these many years. I wonder if a defective product class action suit might be in order ;-)

Reply to
Woodie

I largely agree with your analysis but its having failed on a Sunday, leaving no option to acquire the OEM part, the two nearby parts stores having a sum total of one replacement item between them combined with an immediate need for the vehicle, meant that there was little choice but to accept what was available.

An interesting side note though, the gasketless aforementioned is very quickly and easily removed and reinstalled (a total of

5 mounting and 3 pulley bolts plus one o-ring) and carries a lifetime, free replacement warranty.
Reply to
Woodie

I concur that at incipient seal failure, coolant will commence to pool and subsequently spill from the hole. Being an old car though, I'm hoping that it might survive the remaining service life of the vehicle. In any case I'll keep an eye on it. Unlike in days of old there's fortunately no chance that a failed shaft bearing can put an attached fan into the radiator ;-)

Thank you all for your considerate responses.

Reply to
Woodie

Some people would probally call it the p.. hole. Oooops,,,,, cuhulin

Reply to
cuhulin

One of the places where I used to work was a cotton oil plant.The pumps in the solvent extraction area where I worked, the pumps had square graphited rope packing.It was a constant chore not having the packing glands not tightned too tight and not too loose.That was Hexane fluid (it is kin to lighter fluid) being circulated around inside of the pipes.Very Flamable stuff it was too! The tools we used in there were bronze non sparking tools.Breathing too much of that Hexane fluid would make you ''high'', but it was the wrong kind of a ''high'' cuhulin

Reply to
cuhulin

The health effects of hexane can be a lot worse than was thought just a few years ago. MSDs today often dont show the full nature of the hazard.

Neuropathy and liver damage, perhaps cancer, may result from hexane's breakdown products in the body.

Reply to
hls

It might collect a little bit, but would that really be an issue?

Those bearings are, IIRC, bronze bushings and they tolerate coolant pretty well. The contact with coolant may provide part of the lubricity. (As you would remember, people used to put water pump lubricant in their radiators, which was nothing more than "soluble oil". Ate up the hoses, but maybe lubed the pump shaft a little).

Reply to
hls

I don't know of any modern automotive water pumps that use bushings for bearings. Bushings do not wear well in high speed applications like modern cars and trucks or small to medium marine and industrial engines. Every automotive app I can think of uses frictionless (ball or roller ) bearings in the water pump. In the old days - and I am sure is currently the case - pumps using bushings required zerk fittings and frequent lubrication during operation. I have seen those in older units. I have also seen pumps that use oil cooling and lubrication for the WP bearings. The weep hole in most of these applications is between the water seal and the neaeest bearing to minimize the chance of coolant getting to the bearings. Water pump lube was never for the bearings. It was to provide some protection and longer life for the coolant/pump seals. Most commercial antifreeze/coolant has enough lube quality for this nowadays. You will still find packing type seals in applications that use raw water like marine units to supply water-to-water heat exchanger cooling systems.

Lugnut

Reply to
lugnut

I cant challenge you because I havent taken a water pump apart and rebuilt it in a long time. And that last one definitely had a bronze bushing.

Water or coolant does have some lubricating ability. Block polyols were evaluated as coolant system lubricants, and did work, but it was for the bearing surfaces, not the seals.

The old "soluble oil" lubricants were also for the pump shaft, and probably worked some, but they did eat up the hoses, etc.

Reply to
hls

"hls" wrote in news:MNednRXnmabr- V7WnZ2dnUVZ snipped-for-privacy@giganews.com:

How far back are we going here? 1960? 1940?

I'd be surprised if any car built after about 1975 had bushings in the water pump.

Reply to
Tegger

Back into the 70-80's. I cant be for sure. We very rarely rebuilt water pumps in the company garage. There was just no future in it.

Reply to
hls

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