Leak from Sanicon pump

My Sanicon pump is dripping, not from the weep hole but from the joint in the middle with the half moon holes around it.  I figured it had to be a valve that was not closing all the way so I had my brother adjust them so they close fully now.  It drips right after I dump the tanks and then, as I use it more it stops.  I am thinking I have a valve that is "loose" in the gasket and when more pressure gets behind it it pushes on it and forces it to seal tight.  Anyone have any ideas?  Anyone know what kind of replacement seals go in the Auto Drain three inch valves just in case I get brave and decide to take them apart to repair them?

Hi Bergie,

I just went through a similar situation with a slow drip from my 2010 sanicon.  The reason the drip stops awhile after dumping is because the volume of water trapped between the sanicon and the two tank valves drains out through the leak and no more is coming through the closed tank valves.  So that is good news that the tank valves are not leaking.  The bad news is that the sanicon has a leak.  I took mine apart and found a crack in the housing.  I did some grinding and filling with epoxy and the leak is fixed for now.  You can buy a new housing from various RV suppliers.  Also there are gaskets and a shaft seal that may be the problem, those are available as well.  You may have to just tear it down and see what the problem is.

I didn't buy any parts so I don't have a supplier to recommend, I replaced the paper gaskets with RTV gasket sealer and that worked great.

Bob

Thanks Bob.  A new pump is over $300 so I am willing to do what ever I can to repair/rebuild this one.  Just has been driving me nuts with the leak/no leak situation.  I dumped and flushed the tanks and put it in storage and there did not appear to be a drip at the time.  I went back today to get some things and checked and it started to drip again.  My tanks are as empty as I can get them and since the valves are shutting off any liquid getting to the pump I was completely baffled as to why it continued to leak.  Can there be that much left in the pump after the valves close?  Do you know of any videos or instructions available on how to remove and dismantle the pump?  I want to be as well informed as I can before I start into this.  My brother says to just remove the whole thing and put a manual system in but I don't want to do that.

I had a similar situation at the same point and the housing was not cracked but the "paper" gaskets were basically rotted through.  I remade gaskets with thicker material and that was a definite no-no, DID NOT WORK .  I ended up making gaskets out of plastic coated paper similar to what is on the back of bumper sticker/decals, etc., and the leak was stopped and we never looked back.  What I actually used was the backing from a roll of aluminum ac tape, but because of the one time use I wouldn't run out and buy it, kinda pricey and I had it on hand.  I actually tried the aluminum tape with the backing, but again was too thick in my pump.
FWIW the seals can be repacked with (I used silicone) grease when the pump is apart.

A little leak!

On the last day of our 3 month trip and the last dump at 5:00 AM, in the dark, I opened the gray water valve. Water poured out under the coach. I shut-off the valve. I washed the pavement but did not look for the problem. With a full black water tank and no visable sign of leaking, we headed home. This is what I found.


The macerator bayonet had broken. I've called Carol, she is sending out a replacement at a cost of $40.

I broke the same part (1-70535 Bayonet) and got a new one from Carol for about the same price.
Thetford bought Sanicon and you can get parts diagrams from http://www.thetford.com


This part is a little hard to remove. I used an oil filter band wrench to be able to unscrew the part from the pump.

Ours broke last month and the repair shop was told by Thetford that it was a warranty repair. Our coach is a year and a half old so we were pleasantly surprised but wondered if it is a known problem that they just didn't issue a recall on. In keeping with our not so great luck, the new seals sent with the new part were defective and Phoenix wound up fixing it for us again when we were there.