Lubricant For FPS Well Pump "Motor"

From time to time I pull and repair residential wells and pumps.
I have just slowly as quick as I can pulled 650'+ of 2" schedule 40 pipe to get to our Franklin Electric 6" High Capacity Pump
Model-50FA10S6PE

What happened was we were inspecting the motor and took the sealed cap off the end of the motor. This sealed cap contains a shaft stabizer. It also contains a lubricant of some kind, I think it's a water base lubricant, but it could be I guess mineral oil, IDK. This lubricant is circulated through the center of the motor. When we popped the end off it spilled out, really wasn't much though. It felt just a slight lubricity and the next day I dragged my finger across the shop floor where is spilt and you couldn't feel anything, it just seemed to evaporate.

Now I'm not looking to guess and dump any old lubricant in. I'm hoping someone on here may know what to use and how much if possible. Don't ask me to call Franklin, already did and they're sworn to secrecy. Even when I buy their pumps and parts from time to time, swindlers.

What is a shaft stabilizer? Help us out with what function this has.

It's a spring loaded plate, that has a qty of 3 pads that are each dual pinned for placement. The well pump is attached to the well pipe, below the well pump is the motor. Between the two is a screen, this screen is to keep large sediment from getting into the pump. The small sand and rock still get into the pump, this is what wears out pump impellers. At the other end of the motor the end of the shaft sticks out, it has a brake rotor looking part. This is where the o-ring sealed steel cap is attached. The cap holds the spring, stabilizer assembly, and holds the lubricant. Have you ever had air in your water line? It makes your pipe shake, this stabilizer I am calling helps keep the shaft loaded, from running out. The stabilizer helps the motor and probably pump from prematurely wearing out. It also circulates the lubricant up and down the motors I.D.

This is a submersable 6" diameter water well pump that pumps 50GPM. So when it starts and that well pipe is dry, it has some shake and that's bad for the motor.

The motor is good, the pump is bad. I want to rebuild the pump by installing a new impeller, but I meed to know the type lubricant they use and if possible how much. Do you fill the motor up pump end down and then put the cap on? It's not a flat cap, it's like 6"-7" long I'd say. Any help is appreciated. I would expect anyone that knows anything about these would be involved in drilling wells, repairing wells, or be involved in manufacturing them.

Heavy-duty stainless steel discharge head and motor bracket.
Stainless steel shaft, shell, intake screen, and cable guard provides corrosion resistance and longer pump life.
Glass-filled Modified PPO impeller stage assemblies provide exceptional strength and durability.
Ceramic shaft sleeve and rubber discharge bearing minimizes bearing wear and shaft misalignment.
3-inch NPT heavy-duty stainless steel discharge head.
Modular motor bracket enabling 4-inch or 6-inch motor mount for 5-10 hp units.

Off of manufacture website. Not much, but might give a idea.
This is for the pump, but does gives an idea of the pump.
I will look for the motor, problem is I don't have the motor model # due to tag wearing off. I should be able to find it, although all these submersable well pump motors are designed like this.

FRANKLIN ELECTRIC 10 HP Deep Well Submersible Pump Motor,3-Phase,3450 Nameplate RPM,230 Voltage - 1CXE9'|'2366029020 - Grainger!

Here's the motor listing on grainger, highly overpriced ther as well.

search "dielectric mineral oil"

Is mineral oil used in any such things?

Someone thought it soumded lile brake fluid, but IDK.
It is 10 years old, maybe it broke down to a almost water like consistency?

Petersen, just missed your comment before commenting, thanks for the reply.
I have seen dielectric mineral oil and I will look further into it.

That sure sounds like what I need.

The stuff showed up in a search before you mentioned it, but if I recall it was being used/advertised for use in pneumatic grinder or something. So I just overlooked it and kept looking.

Thanks a bunch Petersen, that's a $2000-$2300 motor on the low side. The good ol'crooks at grainher want $2800.

If was mineral oil it would not evaporate over nite on your floor would it. Maybe it is some kind of silicone and it soaked into the floor. The cheap sump pumps for fish pond pumping out, flooded basements are filled with a mineral oil. That would be bad if it leaked out into drinking water.
Bill D.

its a water/ glycol mix I dont know the ratios of mix but a pump motor rebuilder should be able to get you some thats who I talked to but its a grundfos dealer. grundfos sends it out in basically a milk jug and it does deteriorate over time.
you will need googlefo and just start calling it take a few calls to get someone to help you but you will need the horse power and diameter of the pump

Bill D, I truly doubt this thing would leak, its a 316 stainless I think incased motor.
The pump and motor have been in the well for 10 years and are in cosmetically good condition. You may be right though. Now to your point of evaporating on the floor, I don't know for sure. It is used and 10 years old, I don't know how it would be after all that use. I can't really accurately duplicate this accident again by just spilling fresh mineral oil on floor.

Idacal, thanks very much, that is the first I've heard of this secret sauce or from anyone "I think" that has dealt with well pumps. We had a Grundfos pump in there last time, it only lasted 5 years, but I think it was only a 5HP if I recall. The pump/motor is a 6" diameter 10 HP @ 50 GPM. I've been on the phone, but to the manufacture, that's the problem. I will get on the �� and see what I can find, much appreciation to you and the other members.

The motor is filled with a mix of deionized water and propylene glycol to prevent freezing at a temperature of -40 deg F. The maximum shelf storage time of a pump is two years at moderate temperature. After two years the motor coolant needs to be checked and depending on condition refilled.

Reference: Franklin AIM manual This can be downloaded from the internet.

AIM Manual | North America Water | Franklin Electric

Hi Robert R, thank you for the reply, I have discoveres this as well.
I was also told I could make my own for $14.00. Amzon sells food grade propylene glycol for $13.00 @ 32oz., plus a $1.00 jug of distilled water.

This pump/motor was in the ground functioning great for 10 years unserviced.
That would exolain why there was not as much coolant as I guess you would expect to spill out.

I would like to rebuild the pump, but I am having a time finding the parts.
Franklin has not gotten back to me yet and I haven't been able to find anywhere on their site for replacement pump parts or a rebuild kit.

Seems to me the motor should always be underwater so if any fluid leaks out water would leak back in when it cooled off. I think such motors are smaller then expected since they are liquid cooled and would never run above water temperature as ambient.
Bill D

The pump is filled with a anti freeze mixture to allow it to be stored safely in freezing weather before installation. Once installed, water will slowly leak past the rotary shaft seal and maintain the coolant within the motor housing.
The small clearance on the shaft seal prevents sand from entering the motor housing. The manufacturer fills the motor housing with coolant to permit the pump to be installed as is.

Even though the motor is liquid filled to permit heat transfer from the coils to the surrounding well water it can still overheat if there is insufficient water flow past the motor housing. This is a problem when the pump is placed below the well casing screens. In this instance, the water is flowing from above the pump to the pump inlet. The motor is surrounded by stagnant water.

Overheating can also occur if the pump on -off cycle time is too short. There is insufficient time for the flowing water to cool the motor before the motor shuts off. The Franklin Pump manual specifies a minimum of 3 minutes on time and there is also a maximum number of on-off short cycle times per hour.

The smaller pumps are not cost effective to rebuild. The larger sizes might be worthwhile. I suspect the process involves sending your old pump to Franklin and then receiving a rebuilt one in exchange.

Your pump has 22 stages and is driven by a 15 HP motor.

The original post suggests that there are other problems:

"This is a submersable 6" diameter water well pump that pumps 50GPM. So when it starts and that well pipe is dry, it has some shake and that's bad for the motor. "

THE OUTLET PIPE SHOULD NEVER BE ALLOWED TO EMPTY. There is a replaceable check valve on the pump outlet and there should be a second check valve installed at the well head. If the pipe is allowed to empty the pump bearings will be damaged at start up. The damaged shaft bearings may then cause the impellers to fail. There may also be damage from water hammer. In the worst case the motor will still be spinning backwards during startup if the pump is running on short cycle times.

I did not know water leaked past the shaft seal to refill the coolant level.
Good info, doing this on my phone in full site mode is a pain.

Robert R said:

Even though the motor is liquid filled to permit heat transfer from the coils to the surrounding well water it can still overheat if there is insufficient water flow past the motor housing. This is a problem when the pump is placed below the well casing screens. In this instance, the water is flowing from above the pump to the pump inlet. The motor is surrounded by stagnant water.

Click to expand...

A pump in this situation should have a shroud installed to force water flow past the motor end of the pump.

Robert's comment on a 15 horse pump is on target given the OP's stated conditions. I could only guess at dynamic water depth, but I came up with 12 HP required.

Hello:
The 22 stage 15 HP pump is what would be required for 50 GPM at a water depth of 600 feet and a 40 psi storage tank pressure. I am looking at the pump performance curves for the Franklin J-class pumps.

The performance curves are shown in the catalog:
https://franklinwater.com/media/248807/mj5060_j-class_residential_submersible_catalog.pdf

The 8 stage pump is sold with a 5. HP motor and is designed for a maximum water depth of 250 feet.

The 6 inch 15 stage pump with a 10 HP motor is capable of pumping 50 GPM into a tank at 0 psi.

My very limited experience is that medium size farm pumps in the 500 GPM range have a operating life of 20 years. These pumps are operating for 12 hours continuously maybe once a week during the growing season. This is in a area were sand flows past the gravel pack and the screens and is pumped with the water.

My house pump is 30 years old and runs for 3 minutes to fill the pressure tank. It runs 5 to 10 cycles per day.

Your community well should have a operating life of more than 10 years.

It may be that a 50 GPM pump is too large for your current needs and is running on too short of a cycle time. The majority of the sand that is pumped out of the well occurs during the first few minutes of pump operation. If impeller wear is a problem a better strategy might be to use a smaller pump to fill the 1000 gallon storage tank. The house pressure tank is then supplied with a booster pump connected to the storage tank. This has the additional advantage of a lower cost for the pump and a lower standby fee from the power company.