Community Forums

Midniteoyl · 10-26-2012, 09:26 PM

Quote:

Originally Posted by demoon

Ten minutes after water came up in the shower water started running out into the compartments on the drivers side and through an opening near the rear axle. This continued for an hour or more while they tried to see where it was coming from, with no luck. They finally drained the grey tank and of course the leaking stopped.

they overfilled the grey tank??? No wonder it leaked!

And then they let it go for an hour??

Sounds like you have a vent pipe-to-tank problem.. It happens fairly regularly. Seen where gaskets were left off, rubber connector not tightened, etc..

LandKinaMoho · 10-27-2012, 11:15 PM

Yes on that vent pipe, boring to get to it . All the best with it.

)

demoon · 10-28-2012, 09:58 AM

I thinkI found access to the vent pipe yesterday. I will be checking that out after the weather improves. Not at all bad here yet, but the forecast does not look good.
Thanks again for the suggestions.

bbmechanic · 10-29-2012, 03:31 PM

So this sounds suspiciously like something that happened to our Dolphin. Leaking into the basement and only leaked when tank was 3/4 or more full. Tank was removed - leak was in the corner of the tank and would only occur when the tank expanded. There are several options for repair. It can be "welded" if you can find it. We had to replace the tank. INCA Plastics was the manufacturer for National for tanks and have the molds. The cost of the tank is about $350 so our experience said better to not spend too much time looking for leak once you have checked all the normal suspects. Full bill was around $800 for removal and replace and tank. We spent about $2500 trying to patch and learn all of the above prior to the $800, so hence the recommend not to spend too much time and cut to the chase on the tank.

jldunc · 07-15-2013, 07:02 PM

Hello all. I realize this thread has been idle for quite sometime, but I have a couple of questions. I have a 96 dolphin 535s on F53 chassis. I noticed water leaking down on both sides of the gas tank. I posted some questions on accessing the grey and black water tanks and unfortunately was not able to take advantage of the generous responses. I dropped the gas tank and cut 2 small access holes from underneath and discovered the source of the leaks. One is coming from the grey outlet abs pipe where it connects to the grey tank water outlet and the other is from a broken vent pipe on the black tank. I don't have any good way of accessing the areas I need to get to without more invasive action. In other words cutting some larger access holes. Has anyone seen or personally removed the tanks? The tanks on my dolphin are sitting on 3/4" plywood. On the edges/corners of the tanks there is some 2X4 blocking which I assume holds them or helps hold them in place. The grey tank has a molded "neck" that is appox. 3 3/4" in diameter and there is a hose clamp around this and looks like there is some fitting on the inside which reduces down to the 2" pipe. I am surprised that the fitting would not fit around the outside of the "neck" on the tank. But instead, the fitting is on the inside with a hose clamp compressing it. The leak is not from here but where it reduces down. It has been rubbing on a metal crossmember that holds the 3/4 plywood. Sadly, I can not access the hose clamp to loosen it for it is resting against the 2x4 blocking. The tank is not leaking and I don't want to break the neck on the tank, but in order to fix the leak I need to remove the fitting that sits inside the 3 3/4" neck. Has anyone run into this? The black tank is another issue. I can not reach the area where the vent was. It looks like a supply line and the fitting has cracked off. I live in northern, MN and I am assuming that there was water in the line at some point and it froze and broke off. I am assuming that no one thought to try to blow out/winterize the vent line. I am a newbie. I bought the dolphin last summer and we went on one trip and realized it was leaking. The rv is in really good shape but doesn't do me much good with the leaks. This is something that I must fix myself. Any ideas would be much appreciated. If anyone knows a former National RV technician, please turn them onto this post. I apologize for the long written post. And I appreciate any ideas. - thank you, Jason

demoon · 07-15-2013, 09:45 PM

Original poster here. Jason, you know more about the holding tank situation than the two repair shops I had my rig worked on. First place was an RV repair facility that I had good luck with in the past. After $300+ of looking, they admitted they could not figure out where the leak was coming from, nor how to access the tank. Second visit was the dealer. This place was a National Dealer, back in the day. They told me my tank was not leaking, but that one of the flex hoses from the kitchen sink, which is in the slideout was leaking, which they fixed. Long story, shortened. It still leaks, but only when the grey water tank is over half full. So, when we are camped, we leave the grey open until the day before we are leaving, then close it so we have water to flush out the sewer hose. Not a great solution, but in our situation it works. We also found that we have water getting into the compartment right in front of the rear wheels on the driver's side when it rains. Only happens when we are driving in rain. I have tried looking for the entry point using a light at night - no luck.
None of this helps you, but I am just trying to say that you are a lot closer to an answer than we are. I will be interested in replies that you get, and how you make out with a fix.
Best of luck.
Neil

garygann · 07-15-2013, 10:18 PM

Ihave the same issue with my 08 surfside, grey water leaks when full, I agree that the vent pipe is probably the issue. Mine is too hard to access so I just monitor the levels and drain before full. Good luck.

Walter5555 · 07-15-2013, 10:51 PM

I assume that when you are in a Camp Ground and you have connected to the sewer dump station that you leave your gray water valve open while you are in the Camp Ground.

That way it will not back up on you.

Keep the Black water valve closed until you are ready to leave the Camp Ground then you can flush it with clear water.

If the flush valve does not work you can always get a bucket and pour water down the toilet.

Just a thought.

jldunc · 07-16-2013, 08:12 AM

Hello,
The grey water leak that I have is not due to a vent pipe. It is leaking around the 2" abs pipe after it is reduced down that comes of the neck of the grey tank. The pipe was rubbing against a metal cross-member that holds the 3/4" plywood. It leaks after I have about 4 gallons of water in it. I am wondering if anyone has removed the fitting from the tank before. Mine has a hose clamp on it and I am unable to access the screw to loosen the hose clamp because it is resting against the 2x4 blocking.

The black tank is where the vent pipe broke off. It is the vent pipe the terminates under the bathroom vanity. It looks like a water supply line. I want to fix everything and have it work as it should so I don't have to rely on a sewer hookup every time we camp. - thanks for your reply.

varankins3 · 01-15-2014, 01:12 PM

Quote:

Originally Posted by jldunc

Hello,
The grey water leak that I have is not due to a vent pipe. It is leaking around the 2" abs pipe after it is reduced down that comes of the neck of the grey tank. The pipe was rubbing against a metal cross-member that holds the 3/4" plywood. It leaks after I have about 4 gallons of water in it. I am wondering if anyone has removed the fitting from the tank before. Mine has a hose clamp on it and I am unable to access the screw to loosen the hose clamp because it is resting against the 2x4 blocking.

The black tank is where the vent pipe broke off. It is the vent pipe the terminates under the bathroom vanity. It looks like a water supply line. I want to fix everything and have it work as it should so I don't have to rely on a sewer hookup every time we camp. - thanks for your reply.

Did you ever figure out how to get the fitting off of your grey water tank?

My hubby has sprayed that rubber stuff all over the fitting and it still leaks there. I told him that maybe the fitting is cracked as we have been in areas where we have frozen up. That seems logical to me. Can one buy the pvc fitting at Home Depot? We are in Key West for the winter and there does happen to be a Home Depot on the main drag through town

jldunc · 01-15-2014, 02:02 PM

Yes, in fact I did finally solve the grey water leak issue. It was not very much fun. What I had to do is drop the gas tank and cut an access hole from underneath and I also had to cut an access hole in front of the bed from the topside. The neck that is part of the casting of the tank has a fitting that fits inside the neck. It is secured by a hose clamp. The hose clamp was intended to compress the neck to the inside fitting. In addition to that there was some sort of silicone/caulking sealant of some variety that overtime had degraded. My leak was coming between the neck and the fitting that sits inside of the neck. (In my thinking, it is a bad design to have a fitting inside of another against the flow of water.) The screw to adjust the tension of the clamp was resting against the framing and I was unable to reach the screw. I took a small dremel tool and carefully cut through the band of the hose clamp without cutting into the molded neck of the tank. After that the inside fitting pulled right out. I then cut the 2" pipe back aways and bought a flexible coupler from home depot and attached with hose clamps supplied with the flex fitting. It is very tight quarters but doable. It is quite possible that you can fix this from cutting an access hole through the top in front of the bed without dropping the gas tank. I dropped the gas tank initially to verify where the leak was coming from. I have attached some pictures that I hope will provide some use.