Trivia Q: What's the REAL reason for the weep hole on water pump snouts?

Ashton Crusher wrote in news: snipped-for-privacy@4ax.com:

I was told it was to protect the bearing from coolant ingress.

My Honda's factory shop manual tells me weepage from that hole is normal.

Two things. One it allows atmospheric pressure in to allow the seals to remain seated. If the hole was missing, as the bearings and housing heat up the air pressure behind the seal would increase and damage the seal.

Second is that it also does allow you to check the status of the seal by checking for leakage.

"Steve W." wrote in news:hj7grq$qlf$1 @speranza.aioe.org:

Quoting from several Honda factory manuals I have: "NOTE: Small amount of "weeping" from the bleed hole is normal."

Quoting from a Toyota factory manual: "Visually check the water hole for coolant leakage. If leakage is found, replace the water pump."

I'm confused.

snipped-for-privacy@4ax.com:

WTF? Every manual I've ever read (NB: I've never owned a Honda, nor in fact any Japanese car) says that coolant weeping out of the hole is a sign that you should schedule an appointment with your helping friendly mechanic.

nate

That Honda factory manual is Right. Some houses and buildings have weep holes too, but that is a whole nother story. cuhulin

I was considering trying an ex-wife joke ......

N8N wrote in news: snipped-for-privacy@14g2000yqp.googlegroups.com:

My eyes ain't lyin', I can tell you that. It says "seepage is normal", plain as day, in all six Honda shop manuals I checked.

I would guess it has something to do with pressure buiding up in the pump...

A couple of you are pretty close. The reason for the "weep hole" is that without it, it would not be possible to press the bearing into place due to trapped air. I think I saw this on a water pump manufacturers web page at one time.

What about pilot bearings/ bushings, I don't recall ever seeing a weep hole in the crankshaft

And the water pumps that have two weep holes?

Ashton Crusher wrote in news: snipped-for-privacy@4ax.com:

At first it sounded as though you had absolutely correct information, but then you said "I think I saw this...". A bit contradictory, no?

They are not sealed like a water pump bearing.

Hey, he did use the word "trivia." Anyway, I think the weep hole is there to let you know the water pump needs replacing. Always worked for me.

--Vic

We probably don't know the real reason for the existence weep holes. However, the only thing we need to know is that they exist and they're our friends. :-)

Vic Smith wrote in news: snipped-for-privacy@4ax.com:

Except that your thought isn't applicable to Hondas.

Don't buy it. The bearing's go in first, into an empty housing. No way for air to get trapped.

twisted wrote in news:490b73cb-540e-4bb1-b11e- snipped-for-privacy@d30g2000vbl.googlegroups.com:

It's to protect the bearing in case coolant should leak past the seal.

That's what I was told.

Car #1 had no weepage from the hole, pump did not leak after I cleaned the cooling system with Prestone oxalic acid/baking soda treatment.

Car #2 had weepage that for years never dripped to the ground. Pump leaked a stream after same oxalic acid/baking soda cleaning.