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Chasing a Plumbing Leak in my Sprinter van

| Updated Jun 20, 2023

I had an eventful day solving a problem I always dreaded – a water leak in my Class B Sprinter campervan. The water pump was coming on briefly every 15-20 seconds, no matter how much I tried to get all the air out of my system. It could have been just a bit of debris in the water pump check valve which allowed the water pressure to bleed back down, instead of a real leak, but looking underneath the van, I found a drip. Something was leaking somewhere – hopefully I could get to it and fix the problem. If it was a water line behind a cabinet or underneath the flooring, it was going to be a real headache.

Chasing a Plumbing Leak in my Sprinter van 1The drip was down one of the supports for the fresh tank underneath the driver's seat, but that really means nothing. Depending on the angle you're parked at, water which goes down onto the sheet metal van floor can travel in any direction for any distance before finding a path down and out of the vehicle. There weren't even any pressurized water lines within a yard of the drip, and the tank itself wasn't leaking, because the drip stopped when I turned off the water pump. What I needed to do was look at all the water lines I could access and see where the water was coming out of the pressurized fresh water system. In a Sprinter, the easily accessible water lines are in the ottoman boxes (the cabinetry surrounding the rear wheel wells) and under the galley.  So that's where I started.

Chasing a Plumbing Leak in my Sprinter van 2
The culprit is that white connector, bottom center. Sorry, but I had to redact part of this photo – there are strange things in my unit that don't officially exist.

Everything around the water pump in the passenger side ottoman box looked tight and dry, and under the galley was also innocent of any leakage, despite my suspicions since I had just replaced the faucet a week ago and might have left something loose. You want to find something that's accessible, so I was getting anxious as I checked the driver's side ottoman box, my last hope for an easy fix. Jackpot – there was a glistening dampness on the connector where the cold water went into the Alde pressure regulator and frost control valve. Aldes are combination hot water heaters and cabin heater systems you find in some of the new Roadtreks, and they use what are called Sharkbite connectors. These are snap-in, push-to-connect joints, as opposed to the PEX line crimp connectors used everywhere else on Roadtreks . As luck would have it, I found and fixed a leak on one of these connectors before I ever left the factory, and snarfed up a few extra connectors in case they came in handy down the road. And here I was down the road.

Chasing a Plumbing Leak in my Sprinter van 3
Here's the magician's hat for resourceful RVer do it yourselfers – a panoply of items at your fingertips that you'd have to order online and wait a week for.

I dug into the long-term storage deep under my bed and pulled out the magical fairy bag of odds and ends I had squirreled away in case I ever needed them – extra cabinet latches, circuit breakers, ceiling lights, stuff that you can't buy at Home Depot but you most certainly need if you break down out on the road. I have all kinds of Alde parts, wiring, a veritable assortment of nifty things. I even had an extra goose-neck reading light I installed for one of my RV buddies whose house we overnighted at. And there were two brand-new Sharkbite connectors of the precise type I needed – ones which adapted from the SAE 5/8 inch outside diameter PEX line to the metric 15 mm line used by Alde. They're all color coded for size  – blue is for standard 1/2 inch PEX, which is 5/8 inch outside diameter; gray is for the Euro-spec 15 mm outside diameter PEX.

Chasing a Plumbing Leak in my Sprinter van 4

Chasing a Plumbing Leak in my Sprinter van 5





On the left above is the connector I dug out of my magic bag, on the right is the special Sharkbite tool that allows you to disconnect the lines from the connector. You put it over the water line and slide it up to the connector until it depresses the color-coded rings on the ends, which releases the grip the connector has on the line. Nothing but trouble ensues if you try to disassemble these connectors without the tool – you're going to break something.

Chasing a Plumbing Leak in my Sprinter van 6
The frost control valve. Press the button at the base, dummy.

Swapping out the connector was a ten minute job, but in my desire to minimize water leakage I had drained the Alde by tripping the frost control valve, an Alde feature which protects the Alde from damage by draining it whenever the temperature drops close to freezing, and when I reset it water continued to pour out underneath the vehicle. I'm ashamed to admit I was forced to reference and follow the procedure in the manual I had helped Yan Seiner write four years ago before I got the reset procedure straight – turn the handle parallel to the line and THEN push the button at the base of the frost control valve. Water stopped cascading down under the van. That was a bit humiliating, but you can't remember everything. Apparently, I can't. I had to look it up when winterizing my unit for the trip back from Europe a little over a year ago.

All went well after I got the frost control valve reset – the new connector didn't leak, and the water pump quit coming on two or three times a minute all day and all night. With the right parts, tools, and know-how, many of these problems aren't so scary after all.


RV Lifestyle

Published on 2019-01-29

6 Responses to “Chasing a Plumbing Leak in my Sprinter van”

August 16, 2019at4:18 am, Judy rach said:

Your review “what’s under your etrek” is wonderful. I have white pipes connected to the Webasto with pitcocks for winterizing. Have been under there three times, cannot find them. Can you shed light. Thanks, Judy

July 30, 2019at12:29 am, steve harmon said:

where can I find that blue/grey Sharkbite connector?

January 30, 2019at10:26 am, Art Lehmann said:

Totally unrelated to your plumbing problems, (and resourcefulness) i’d Like to explore your European adventure a bit more. Is there a blog site i’ve Missed, or perhaps even a book?



January 30, 2019at10:52 am, campskunk said:

no book, no blog, it’s just a series of blog posts I wrote for Mike here on this website. look back to the January 2017-November 2017 period and you will see them.

January 29, 2019at10:55 am, campskunk said:

Yan is innocent, in this particular case anyway. he wasn’t the one slipping me parts.

January 29, 2019at10:27 am, Mark Bryant said:

Sounds to me like Yan saved you giving you all those spare parts. Nice article about two resourceful guys.

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