MikeP
Legendary Member
- Joined
- Apr 12, 2005
- Messages
- 8,674
- Status
- OTHER
- Hatteras Model
- Not Currently A Hatteras Owner
I noticed, being back aboard, that the GM water pump was having some difficulty maintaing pressure with fixtures open. Previously, when taking a shower, the pump would cycle as needed to maintain pressure. Yesterday eve it had to run constantly to maintain pressure.
This AM I disassembled the pump and discovered that the rotor was excessively worn. I thought I had some spares but turned I only had spares for the head pumps.
Anyway, I ordered a couple from Raz (and a new seal kit AND new bearings since I discovered that the current ones are a bit rough). In the discussion, I learned that the method I have been using the past couple of years for dewinterizing probably caused the problem:
When we first bought the boat and as I became familiar with these somewhat odd pumps, I primed them as per the recommendations, dumping water into the priming port. Later I discovered that the pump can self-prime if the water tank is totally full and I cycle the switch on/off a few times, letting the pump run for 5-8 seconds at a time until it finally primes. So that's what I've been doing for several years. If you have been doing that or something similar, STOP doing it. You are damaging/wearing out the stator unnecessarily quickly. Prime it as per the GM instructions.
Per the tech at Raz, ANY dry running at all is very hard on the stator - even a few seconds. The spinning rotor will melt rubber of the stator if water is not present and deposit it on the rotor. The tech stated that the pump should always be primed with water through the priming port and never started dry. Additionally, they recommend that when a stator is replaced, it be lubricated internally with silicone grease.
So at the moment my boat is actually connected to shore water which I find very traumatic. Oh well, I'll have to deal with it for a couple of days.
This AM I disassembled the pump and discovered that the rotor was excessively worn. I thought I had some spares but turned I only had spares for the head pumps.
Anyway, I ordered a couple from Raz (and a new seal kit AND new bearings since I discovered that the current ones are a bit rough). In the discussion, I learned that the method I have been using the past couple of years for dewinterizing probably caused the problem:
When we first bought the boat and as I became familiar with these somewhat odd pumps, I primed them as per the recommendations, dumping water into the priming port. Later I discovered that the pump can self-prime if the water tank is totally full and I cycle the switch on/off a few times, letting the pump run for 5-8 seconds at a time until it finally primes. So that's what I've been doing for several years. If you have been doing that or something similar, STOP doing it. You are damaging/wearing out the stator unnecessarily quickly. Prime it as per the GM instructions.
Per the tech at Raz, ANY dry running at all is very hard on the stator - even a few seconds. The spinning rotor will melt rubber of the stator if water is not present and deposit it on the rotor. The tech stated that the pump should always be primed with water through the priming port and never started dry. Additionally, they recommend that when a stator is replaced, it be lubricated internally with silicone grease.
So at the moment my boat is actually connected to shore water which I find very traumatic. Oh well, I'll have to deal with it for a couple of days.
