Repairing broken sink drain flex hose.

[Gary and Judy]

Drain Hose Repair – 2001 Alpine 34 fdds

The kitchen of the Alpine is in the slider on the left side of the coach. The sink drain and other utilities rest on a slide plane under the kitchen sink. In the 2001 coaches, and probably others, the drain hose is flexible but rather stiff. This hose connects the two inch sink drain PVC piping in a sweeping loop to the two inch PVC “tee” just above the grey water tank behind the shower. The run of the “tee” is the tank vent and continues up to the roof vent. The branch of the “tee” receives water from the kitchen sink via the above described hose.

After many cycles the connection between the flex hose and the “tee” separated. Both parts of the connection were intact, although the branch of the ”tee” had a crack in it and broken pieces of the glue-in fitting on the end of the hose were still in the “tee.”

Repairs were accomplished as follows:

• I removed the center shelf of the sink cabinet to gain access to the area.
• I used a 2 inch hole-saw to clear and true up the receiving bell in the branch of the “tee.”
• I purchased these supplies:
  • Female screw fitting to two inch female glue fitting – to fit the hose end.
  • Male glue fitting to female glue fitting – to glue into the branch of the “tee.”
  • One two foot section of two inch outside diameter vinyl shop-vac hose. (At Ace Hardware.)
  • PVC pipe primer and PVC pipe glue.
  • A tube of “3 M 5200 Marine Adhesive Sealant” or equivalent product.
• I primed and glued the male glue fitting into the branch of the “tee.” Be sure to slather it good and rotate the fitting in the fitting to spread the softened plastic well. (This leaves you a virgin female socket to accept the vinyl hose.)
• I screwed the other fitting onto the flex hose. (This also leaves you a female socket to accept the other end of the vinyl hose.
• I cut a four inch section of vinyl hose, and trimmed the ends square and true.
• I built up a layer of the 5200 caulk inside the socket on the end of the flex hose, and also forced the caulk to the bottom of the spiral groove in the first half inch of one end of the vinyl hose.
• I let this assembly set for an hour for the caulk to get rigid.
• I looped the hose assembly back under the sink and aligned it with the exposed socket on the “tee.”
• I repeated the 5200 caulk application on the other end of the vinyl hose and in the socket of the “tee.”
• I inserted the caulked vinyl hose into the caulked socket and braced the flex hose with some heavy objects to keep things properly aligned until the caulk had set up completely. This would be at least overnight.

I will save the rest of the two inch vinyl shop-vac hose for future repairs. So far it has been working well. All of the flex now is absorbed in the vinyl hose. Before there was a lot of torque applied to the “tee.”

Just a reminder: It is so tempting to place supplies in this little cupboard. To understand why not, open the door and remove the hatch. Have your mate run the slider controls and watch how the hose arches across the whole width of the slide deck.

[takepride]

Nice job Judy!

[takepride]

G&J:

I have one concern about the flexible vacuum hose. I've seen them of several different materials. The common ones become a bit brittle with age and heat (near water heater or just during storage). Some high quality hoses have a clear plastic film over them and are weightier. True PVC flexible conduit is available for electrical wiring (seen at Lowe's just today) in various sizes and has water-tight fittings to boot.

I'd be most concerned about the connection of the flex-tube to the PVC or ABS fittings. All that caulk might be a place to collect debris inside the fitting.

Lastly, though I haven't checked mine (and now I will) the type of plasic is important. The glue to hold PVC does not work for ABS and vice versa, in spite of some glues' claims to handle both (it just ain't true). The photo looks like ABS and problems arise when connecting ABS to PVC. (I had that problem myself on an underground drain that I then covered with a stunning slate patio. It ate deeply into my SWOM.)

Not that I'd change anything right away, but I would keep a close eye on it.

[Rich and Cork]

I have had issues with the rubber connection to the drain on my 2001 since last Summer. It had cracked and leaked. Did not notice until the leak became large. I purchased the new rubber adapter and connected up again as the factory did. Have had it come loose a couple of times. Even purchased a second adapter. Has been OK the last few trips, but I am now paranoid about looking at it before using the kitchen sink each time the slide is extended. I have looked for more flexible hose, but have not found. I assume over time the hose has become stiff. I did make a bit of a notch in the cabinet with the slide in the extended position so that it did not put a stress on the rubber adapter. Will see. This worked well for over seven years.

[Gary and Judy]

Thanks Takepride:

I will check out the flex conduit next time I am close to Lowe's or Home Depot.

I just checked and the fittings are ABS. However the glue I used was for CPVC pipe. I do know that it really softened the ABS fittings and they locked up tight.

Gary

[dgerstel]

Flex PVC pipe is available in 1 1/2" and 2" sizes, and can be obtained from pool and spa shops. This is what WRV uses in out 2007. The "flex" PVC is not real flexible and the piece used in our coach is long to allow for its flexing. I have found that the flex PVC does get stiffer with age. There is a glue available for use with PVC and ABS together. I have found it at some Home Depot, but not always.

[John-D]

I usually use automotive radiator hose for that kind of thing... However, that said, Good job

[takepride]

Dale:

I've used the glue for connecting PVC to ABS. It does melt the PVC a bit, but never chemically alters the ABS. If the joint is not pressurized (like a drain-pipe in the ground) it works, but if the connection moves (like in a motorhome) or is under pressure (backed up drainage, verticle flow, heavy flow or freshwater pressure, it gives way.

When we use it in buried drains, we also surround it with concrete to prevent flexing.

[Gary and Judy]

Report on above fix after 18 months:

I am happy to announce the repair is still performing perfectly after 18 months.

Gary

[wa8yxm]

I too use automotive radiator hose for Flex Drain hose repairs.. Though I've never done one in a motor home.. Did one in my parent's house many moons ago.

Worked very well for many years and when they moved the "Sink" to another house... The professional (?) plumbers.... Kept the hose in the line.

Lasts about a decade as I recall

That hose is designed to take chemically treated water at over 220 degrees and under pressure... As a drain hose.. Well. let's just say "Loafing" is the word that applies.