LTP 750 Pump bearing replacement

Leisure Time Pump repair - LTP 750

A while back I scored a nice second hand pool pump courtesy of a friend that sensibly recovers gems like this from the local council roadside collection (thanks Mark). Anyway, it found a new life as part of my cobbled together pool filtering system along with a number of other second hand pvc pipes, connectors and valves.

The arrangement has been running well for a couple of years now keeping our $200 kmart kids pool nice and clean, however, recently it started making an ever increasing whine that eventually got to the point where I could hear the resonant frequency from the front street.

Not normally being one to delve outside the realms of computer software and electronics, I decided I'd take a shot at fixing it. Maybe it was something simple I could squirt some oil into. (Ha Ha)

Ok a few bolts and the pump assembly separated from the motor body, so far so good.

Now to remove the impeller... hang on no nuts, bolts, screw heads... Hmm if I force this thing I'm likely to break something and then I need a new pump.

A quick search on YouTube and I discover these The amazing Pump Guys and six or seven instructional videos later I found myself educated enough to get down to the rotor. At this point the source of the noise became apparent. A 6202 bearing on the front side. Ok time to invest in a bearing puller and a new bearing from my local BSC bearings

Getting the bearing back on the shaft was nice and easy using a bit of old pipe that Dad turned up on the lathe for me. A few careful taps of the hammer moved the bearing nicely down to its seat.

Now for the re-assembly. There are four long "through bolts" that hold the ends on the pump and keep the armature centred, the bearings press fit into recesses in these pieces of cast metal. I first tried pulling it together by assembling and then tightening the bolts, however, the armature was binding so I loosened and started again, this time tapping with a rubber mallet.

Weirdly, each time I got the case back together it would spin freely until I tightened, and then it would bind. I tried rotating the back and it improved slightly. (The front has a drain hole that needs to point downwards so it has only one way it can go on)

Time to spin it up (fingers crossed).

You can see the through bolts in this shot. Initially I left them loose, ran it for a while and slowly tightened it. Each time I ran it and then tightened, the armature seems to spin more freely as it bedded into position... And the great part about this bench test was the uncanny silence.. Ok, not quite silent, but sounding more like it should and less like a banshee.

Time for the final reassembly:

This bit is easy thanks to alignment slots and helpful arrows in the plastic to remind me which way is up.

Ok, now where did all those rubber seals go?

Nearly there, just have to add the o-ring in front of the seal

By pressing the spring loaded seal back the small o-ring can then be seated in the shaft groove. After this, there is one more large o-ring that goes around the impeller assembly and makes a seal when the plastic pump body slides on.

Finally, the new improved almost silent version... 

Cost was $20 for the bearing puller and $10 for the bearing. (3 times the price from an online pool parts place)

Now that the "Banshee" is gone from the pool filter, maybe I'm feeling game enough to have a go at removing the "Freight Train" from the washing machine spin dry cycle.