Pump Shaft Seal Kit Fitting Instructions

Pump Shaft Seal Kit Fitting  Hot Tub DIYIf your hot tub has a leak from the back of the impeller housing you will need to replace the shaft seal on the pump. This can sometimes be a little tricky, the following guide should help and gives you a check list if you have never changed one before.

Difficulty level - Medium to hard depending on location and age of the pump.

Hot Tub DIY Tip: To ensure correct hot tub parts are ordered, you will need to remove the old shaft seal from your existing pump to compare the size the shaft seal to the information given here as there are a variety of different types of hot tub pump seal kits to choose from

Shaft seals consist of several components but are the same and all pumps are the same: a ceramic face, a carbon face a small spring and a retaining bush's.

Tools Required

Cross head screw driver

Spanners to remove pump retaining bolts

Small spanners to remove wet end retaining bolts

Filter whip to remove impeller

Lubricant - (Vaseline or Other)

Flat Headed Screwdriver (Or Armature Tool)

Remove the cause of the faulty seal

Seals fail due to chemicals, not age or any other reason.

Make sure you are using quality hot tub specific chemicals and not swimming pool or cheap re-branded chemicals. If you are using quality chemicals pay attention to the pH in more detail and check you're test strips are not faulty.

It is cheaper to pay slightly more for quality chemicals than it is to replace and repair hot tub / spa components.

How to fit.

*note: never hit the shaft of a pump with a hammer it has to be perfectly straight to produce a seal.

  • Remove pump
  • Remove face plate (screw driver)
  • Remove Impeller (rotates anticlockwise)
  • Remove wet end (make a note of how it fits and which way the wet end return is pointing)
  • Clean the Impeller and the wet end faces where the shaft seal will sit.
  • Clean the shaft buy removing the rust with a screwdriver and putting a little Vaseline on to prevent further rust.
  • Use a little silicon to slip new hot tub pump seals into location and make sure they are correctly seated.
  • Put the wet end back together making sure that the impeller is completely screwed on by looking down the return on the wet end.
  • The 2 Ceramic plates of this shaft seal must meet to create a seal.

*Note: Never run a pump without water or without bleeding the air out if plumbed for more than 15 seconds, the seals are designed to be water cooled and will get hot.

Broken Impeller

The main reason for a shaft seal change is due to the seal failing and letting out water, if the nut that holds the impeller on is still seated correctly and has no cracks enabling it to fall out / off and the impeller itself is still in 1 piece the all you need is the seal.

Note: The shaft will always be cracked snapped or split, this is due to the steal underneath expanding due to rust. If this is the case do not rush out to buy a new impeller, because it may not exist, cut of the swollen part of the plastic that covers the shaft, and fit the impeller part of the seal with a little silicon to guarantee a seal.

*Note: Never put any dirt or silicon on the faces of the seals, they will wear very quickly or fail straight away.

What to do if the seal still leaks

It is possible that the impeller isn't screwed on completely check this first.

Is the seal seated properly

you may need to put a small washer in-between the impeller housing and the motor to shim out the seal for a tighter fit. (this is very rarely required)

*Note the shaft of the pump shaft needs to be able to rotate freely and shouldn't feel tight.

If all else fails we offer a service to replace these parts for you, and arrange collection of you pump to our office to repair it for you. - Contact for more detail.

Hot Tub DIY - Parts and Advice

This guide was written by Jon Pennington @ Hot Tub Help Ltd for the Website www.hottubdiy.co.uk.

Please note all Hot tub Parts sold are UK Spec, which means designed for 230 V at 50Hz