Johnson Impeller Pump

[squarehead]

I am currently putting together my Johnson pump
it's a F35B-9
I can't remember if the seals go opposite to each other or face in the same direction with a spacer in between
Does any one know?
I don't want to put it back incorrect!!!

[Viking Sailor]

The smooth sides of the seals seals face each other. The impeller side seal has the spring side of the seal facing the impeller. The other seal has the spring side rotated 180 degrees so htat it is facing away from the impeller. Volvo recomme4nds not replacing the O ring between the seals. And, don't block the drain holes with the seals.

[squarehead]

Great, Thank you!!
I thought it was that way but I just wasn't sure
It goes back in tomorrow

[Acushla]

When there is pressure present it should try to press the seal lip to the shaft to get a better seal to help your understanding. Also most of us change the springs for O-rings when on water sealing duty.

Jim

[squarehead]

I managed to download the assembly print for the pump. It doesn't show any springs. Am I missing something? I didn't find any springs while disassembling. The seals require a press to assemble correctly with a coating of lubricant so they slide on easier. I'm planning to use an arbour press over a socket to protect the seals and space them over the drain hole

[Acushla]

The seal springs are small coil springs that help keep the pressure on the lip in operation. They all have them and are integral to the seal structure. Seals have two parts generally, the seal proper and its spring.

Jim

[squarehead]

I got you now, the springs in the seals.
When I purchased the replacement seals the springs were part of the seal
So if I understand you correctly you remove the spring and replace it with an o-ring. Do you find that altering the seal this way gives you a better seal or does it last longer? I remade the shaft out of stainless and finished it to the high end of it's tolerance If you replace the o-ring what size do you use and will it last longer than the spring?

[Acushla]

I buy my seals from a seal supplier and get them to change the springs over to o-rings at time of purchase. If you want a size just flip out the coil spring and measure it. The o-rings do not corrode and weaken the same as a coil spring.
The shaft finish for a shaft that has seals running on it needs to be a ground finish and hard. My pump shaft is chromed by the manufacturer and provides the requisite hardness and wear characteristic. A ss shaft will be quite soft unless you made it from a hardening type ss in the 400 series and heat treated it before finishing to size. Otherwise you will find that the seals will wear a groove in the shaft over time.

Jim

[squarehead]

I have the two old shafts from rebuilds from the original owner and they are both soft, so maybe that was the problem. They do show wear, but I believe they were ordered from the supplier. I intend to have the stainless ion nitrided to give it a nice hardened case yet allow for some flexibility to prevent it from breaking
Thanks for your help