Bucket test

how fast should my RWP suck up a 5 gallon bucket full of water when I'm doing the bucket test on the pump?

I fill up a 5 gallon bucket before I start the boat, then I keep the hose on feeding the bucket. I can typically run it about 5 minutes before the bucket is empty - even with the hose on I cannot keep up with the water demand.

Like people are saying, you should see the level drop steadily, maybe 30 seconds to drain the bucket? Not sure of exact amount of time, but very fast.

What did you see when you ran the test?

but i've had trouble with rwp--sometimes leaking. had to re-tap one bolt hole so I could tighten up...twice. I think it's sucking air on the intake side. However, I think replacing manifolds is good idea anyway....always a little too hot to touch in summer.

Thanks David. That's what I think too. Impeller is good...change it bi-yearly. The O ring in the pump has been an issue too...It never seems quite thick enough, but I've got several and they're all the same size. If you used permatex, which side of the brass plate would you put it on? pump side or housing/impeller side? I would think pump side, right?

I ordered a new rwp today. The bearing seems good, and it does suck water, but I am thinking it's just not enough--like you said. I figured it should empty that 5 gal bucket in 60 sec or less. I may try the permatex idea and if that seems to fix it I may send the pump back.

I appreciate your suggested sequence...I agree.

If youre only overheating at idle, then you most likely have an air leak between the pick up and the pump. The increased RPM allows the increased water flow to overcome the small air leak. Check all hose ends for damage (cracks, etc) and tighten all clamps with a nut driver (not a screw driver). Also verify your strainer gasket is in good shape and that the bowl is installed very tight.

When a RWP is starting to pull air and fail, it will usually show up as an overheat at higher speeds/loads, not idle. Same goes for a blockage on the intake side.

I have several RWP's that leak externally a bit... but they must not be pulling air because they allow the engine to regulate proper temperature just fine under all conditions.

I have checked all possible air leaks including strainer (doesn't mean I didn't miss one) and think everything is tight. Disconnected hose from hull pickup and did bucket test there. Disconnected hose from tranny cooler and did bucket test there. Same results on time it took to empty bucket, so I'm thinking there is not an air leak between pickup and pump (again--I could be wrong). That's why I'm thinking it may be sucking air at the pump. The bearing seems to be good though.

I will recheck hoses tonight, perhaps I've got a crack in one--or the strainer. I think what Tim says makes sense...overheat at idle sounds like sucking air somewhere besides the pump.

Thanks guys. Merry Christmas!

Run a RWP intake hose straight into the bucket. Go buy some clear vinyl tubing for IN and OUT, this way you'll probably see bubbles coming out if the pump itself is sucking any.

Yeah, I'm usually on top though and then do like 19 edits.

Point being, you can do more free/cheap tests before paying $400 for a new pump. Swapping in a known good one is a always a great idea too.

And we still don't even know how exactly fast a good one empties a bucket...

I love it when I'm not on here for several months, but one post gets responses from old timers like Gary, Tim, and Kevin.

I may not get back to this until Sunday now (Irish playing tomorrow and I have to go to a frickin wedding). I did the bucket test with just the intake hose to the pump put directly in the bucket, but I haven't taken the outlet hose off for any test yet. Will do that like HW said and probably get clear hose to see if I can see bubbles.

OK. Bucket test with clear hose on both intake and output. Running at idle the 5 gallons empty in 90 seconds. There are bubbles in the outflow, but they aren't consistent--some bubbles, then no bubbles, then bubbles again. I made new gasket on the pump side of the brass cover plate and feel confident in the Oring seal. It's just not pumping enough water.

The Dude wrote: I love it when I'm not on here for several months, but one post gets responses from old timers like Gary, Tim, and Kevin.

Finally..not included in the 'old-timers'...altho I bet you did not mean age!
None-the-less...it is always cool to have a Dude sighting!



john

correct 63. Not plumbed to engine...clear hose about 1 foot out of outlet from pump...not connected to thermostat housing. So manifold pressure was not an issue.

Jbear, you are definitely an old timer. However, since you can still barefoot, you are exempted from the title.

installed new rwp today. Wallah. Not only is it sucking the bucket dry fast (about 30 seconds at 800rpm), I took it to the water and ran it and it never went above 125F. manifolds and risers were warm, but not hot at all.

Apparently when I re-tapped the bolt holes on this pump, it's been sucking air ever since. Only in the last year did I really notice the temp jump, but good grief, my risers have never been this cool (Of course I'm usually running in 90 degree water instead of today's 50 degrees, but still!).

Since we were out there, I pulled my 19 year old on a quick run. Nothing better than a January pull.

thanks guys.