Life expectancy of pumps

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B

budysr

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LifeTime Supporter
Aug 26, 2007
129
Pensacola
I have a two speed sta rite pump that is only about 3 years old. It became very loud this summer and I had the bearings replaced at a local elec motor repair shop. They were very expensive(over 100 bucks). Anyway, the pump was whisper quiet when I hooked it back up, and had worked fine the rest of the summer till about a week ago! It has now become loud again and I'm certain the bearings are shot again :rant: Seemed to really show up after a couple days of heavy rain :grrrr: I don't know that it's still covered from the repair shops job, and I'm Dang sure not gonna drop another 100+ on another bearing job again!
How long are these things supposed to last nowadays? I had one "professional" tell me that they aren't made as well now, and it would be better to look for a new pump altogether. Didn't believe that, but it does appear that I may be wasting my time with this lemon of a 3 year old pump.
Thoughts?
 
I got 5 years out of my Dynamo and the only reason it quit was that the casing on the bottom had rusted through to the motor itself. As long as the pump is not run "dry" for an extended period of time the bearings are usually o.k. I have heard a lot of pros and cons as far as replacing the bearings. It seems to come down to the quality of the replacement materials, quality of the original pump, and the quality of the person doing the work. Unless you can be really confident in any of those factors you would be better off getting a new pump. I would check with the place that did the repair and see if they will offer any warranty or discount to fix it again, and then go ahead and start planning on a new pump. Then you can use this one as a back up.

If you think water might be getting into the works and fouling things up you may try getting a pump cover or making a shelter for the equipment.
 
I think I would also suspect the front seal - the one which is supposed to keep the wet side wet and the dry side dry. If it is not doing it's job, it will allow some of the 'dry' to leak out of the motor side. The motor's front bearing depends upon having a full load of 'dry' for longevity. If it doesn't get enough dry, it will rust/corrode and fail.
 
Replacement ball bearing assy's have gone down in quality in the last 10 years, blame the global market and cheap imports driving the price down. In general I have found the following bearing makers to have superior products and use them interchangeably when ordering replacements, NTN, CR, Timken (premium price usually), SKF, FAG and a few others I can't remember off the top of my head. If there is no name on the bearing I don't buy it...period. "Kit sets" are usually the worst offenders unless it specifically says on the product labelling the mfg of the bearings used in the kit...pretty rare these days.

I have found much of the problem with new bearings is the low quality grease used to pack them and poorly fitted side seals or seals of poor quality materials, for my personal items I usually pick off one side seal and use a high quality low viscosity synthetic grease to pack them 1/3-1/2 full after they are properly cleaned with contact cleaner. One item you can sometimes buy that is a superior item off the shelf is a "snowmobile" bearing, these have synthetic side seals and synthetic grease from the factory so you can use them as they come out of the package...they cost about 10 times the price of a regular bearing but they don't come in all sizes, check the chart below to find out if your motor bearing is listed.

http://www.ntn.ca/model_compatibility.htm

You can garner 90% of the increased life out of a bearing by just cleaning and re-greasing with a superior synthetic grease, proper installation goes without saying and I have seen my share of installation related failures which seems to have become a lost art amongst the next generation of techs out there who seem to think a hammer and punch is OK for installing new bearings.

My current pool pump motor is on its 20 year and is requiring overhaul this winter, I intend to overhaul it using individually bought bearings and synthetic grease to make it last another 20 years. The actual bearings are OK but the grease has dried out and caked, keeping the motor dry and out of the rain will keep your pump in good condition for much longer than one left out in the weather. A leaky mechanical seal will shorten the life of a bearing a 100 times so these should be addressed at overhaul to insure your investment isn't wasted.
 
I've seen bearings which have been running for longer than I've been alive, and I'm old. Properly sized to the load, properly installed, lubricated, and protected from environmental contamination, there is nothing in a bearing's design which should allow it to fail.

When bearings do fail, it is invariably one or more of these things:
1) Improper installation. This is a biggie, and probably the biggest killer of bearings. 'Improper' can range from impact/brinelling damage to misalignment to dirt and contamination to improper lube/packing and improper seal installation, which is contributory. There is a lot to take into consideration when bearings are installed, and it is no wonder that most failed bearings have been given a death sentence when they were installed.

2) Contamination. The tolerances of bearings are miniscule, and there is no clearance for any form of trash. I have personally witnessed a bearing destroyed by a tiny bit of cigarette ash. A very small bit was tapped into a spinning bearing (spun by hand) and it ground immediately to a halt. The bearing was destroyed, as the races and balls were brinelled by the ash. I saw this with my own eyes. It is a wonder to me that any vehicle wheel bearing is able to survive a single brake job. Water is also a problem, especially once the surface of the metals begin to oxidize. Chlorine is also a strong oxidizer, and will exacerbate the damage.

3) Lubrication failure. Most often caused by seal failure, using the wrong lubricant, not enough lubricant, too much lubricant, or bad design. Back in the late 70's, car dealers had problems with vehicle axle bearings due to 'false brinelling' caused by vibration during the distribution trips on trucks and rail cars. Vibrating while stationary, the races became imprinted with the roller patterns causing ride vibrations and customer complaints. Thicker grease in the bearings at assembly fixed it.

4) Faulty design. Possibly overloading causing a push past the design limits. These failures are probably the least frequent, but are often the hardest to diagnose and correct, until a lot of failures can be logged. Loads, shaft/bore sizes and parallelism tolerances, heat, lube, sealing, all the things that must be considered at design time, all can cause problems.


Just some ramblings from my experience.
 
Thanks for the feedback guys. I suspect faulty installation of the new bearings to be the problem. But I still don't believe the original build of this pump should have gone bad in 3 seasons. Seems like I remember the repair guy saying something about that front seal too. He had broken the metal plate on the front of the motor by the shaft when he disassembled. I have no confidence in taking this thing back to the same place(they already ripped me off on the price anyway) I may just search for a new pump altogether. Not sure I want to risk more $$ in this one again
 
A 2sp will certainly serve you well, but if you are on a budget I have been running mine on a 0.5hp (fullrated) Pentair superflo and love it, very quiet compared to my neighbors 1hp uprated pump.
 
Interesting original question.

I've been thinking along the same lines and have seen the results others posted in replies. Have also rebuilt several pumps with various parts and have seen the damage over the years due to weather, rust, dry, wet, you_name_it .. condition(s).

This led me to conclude I wanted a pump that would run almost 24 hours a day, if not literally and I wanted the full system that would support as complete automation as possible.

The Pentair IntelliFlow VF seems to fit the requirement and considering that I have in the past spent 500+ for 1 HP pumps that lasted only 3 years until repairs needed, this VF will likely pay for itself in 3 years in power savings alone. It is now running literally 24 hr/day and uses just 122-130w of power which is pretty amazing for a 4 HP (with service factor).

Another reason I wanted a system that would always run is that all cars I've had that were in constant use had 300,000+ miles on odometer before any major repairs. Something to do with maintenance, oil, reduced startup wear and engine temperature. Figured it might work for a pump that runs at 10% of it's capacity same as for a car engine.
 
I have some customers still using the same pump and motor that was installed 10+ yrs ago when the pool was built with no problems at all. On the other hand ive swapped motors after 2-3 years. Its frustrating to say the least. NOTHING is built well anymore. It really bothers me when i install a new motor and i see that darn "made in china" sticker. What happened to america making good quality products to serve its american ppl??? IM only 27 so im only going onwhat ive been told by guys before me. If large companies werent alll about making large amounts of money and using cheap products they could build quality products HERE! Besides, if i had to,I'd pay more for something i knew was built well, and buit HERE :blah:
sorry, rant over :grrrr:
 

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I realize this is an old post, but thought I'd update my last post about our pump getting loud, in case it could help someone in the future. The noise on our pump, as it turned out, was that the pump was jarring a bit. I tilted two brick pavers onto the plastic thing that the pump is bolted to and it's been purring like a kitten since - and still going strong today. So for those of us with the above-ground pools that have the little cheapo plastic base, bear that in mind if your pump starts getting loud after a short while.

Update (Aug. 2013) to last year's (2012) post: Our pump has been running on low 24/7/365 since we installed it 4-5 years ago and have never had a problem with it. I don't even turn it off to replace the skimmer socks - it's easy enough to just pull the sock out, then the skimmer basket. The socks work so great that I rarely have to backwash. I still keep the pavers sitting against the plastic base - really should take care of that issue, I suppose - and it just hums along.
 
I'll also add to this older thread. I have to replace a booster pump for my Polaris cleaner. Its only 3 years old. A guy at the motor repair place said it has an internal short. He said I need to get the new one covered so rain and snow aren't dumping on it. There's also some fine dirt in the pump (kicked up by rain)....so I need to make sure there's no dirt near the pump.
 
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