Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 10, 2025 ...

Freshwater check valve and greywater plunger issues

April 22, 2022, 02:29:17 pm

Hello Foretravelers,
Just got back from taking our coach out to an RV park to do some spring cleaning and prepping for sale. There were a couple of things I couldn't solve:
1) Water comes out the back end (hose intake) when I turn on the coach water pump while the hose is disconnected from city water. Will a new check valve solve this problem?
2) I couldn't seem to re-engage the greywater plunger to completely seal it after draining and flushing. Had to drain it completely before capping.

Just checking to see if either of these might be straightforward fixes worth saving the standard $160/hr?

Suggestions would be appreciated!

Thanks,
Mike

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Re: Freshwater check valve and greywater plunger issues

Reply #1 – April 22, 2022, 03:09:58 pm

Two check valves. One in the pump, one in the fill path. I replaced the pump and then the fill check valve last year. Problem solved. Same year coach.

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Re: Freshwater check valve and greywater plunger issues

Reply #2 – April 22, 2022, 03:11:39 pm

For #1, sounds like the check valve for shore water inlet needs to be replaced.

For #2, you can try spraying silicone lube on the plunger handle and work the blade.  Worse case is just replace the valve-- not expensive and just 4 bolts (at least on earlier models).

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Re: Freshwater check valve and greywater plunger issues

Reply #3 – April 22, 2022, 10:44:42 pm

Temp cap with plastic male hose plug, the freshwater input when hose is removed until fixed. Good emergency cheap part to carry.

Male Hose Plug

Close gray & black drain valves, pour in a couple quarts of inexpensive vegetable oil. Let it settle to bottom, then many quick open/close drain valves could coat & lube the valves and make them easy to open and close. Good periodic maintenance step to do.

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Re: Freshwater check valve and greywater plunger issues

Reply #4 – April 23, 2022, 07:49:40 am

Agree on trying vegetable oil as a blade lubricant.

But, oil floats on water, so to get it to the valves, the tank will have to be completely empty. Easy to pour some down the toilet for the black tank.  Gray is a little more difficult as the P traps have water in them.  If you have either compressed air or a 3" or so diameter hose, you can blow out the P trap before adding the vegetable oil.

Good luck.

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Re: Freshwater check valve and greywater plunger issues

Reply #5 – April 23, 2022, 10:06:37 am

This is a little late but when using split bolts, after making the connection and think you have it tight you need to twist and move connection around for a little bit and then go and retighten.  You will be amazed when you go and retighten how loose is was.

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Re: Freshwater check valve and greywater plunger issues

Reply #6 – April 24, 2022, 12:17:33 am

Hey, thanks guys! I knew I can count on some of my favorite guys on the best of forums!

Will tinker and report back...

Mike

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Re: Freshwater check valve and greywater plunger issues

Reply #7 – April 24, 2022, 11:51:35 pm

Our first RV was a 5th wheel with four dump valves to control black/gray/macerator.  Each valve had a grease zirk installed just above the pull handle.  I thought this was normal and applied a shot of grease every now and then when pulling or pushing the handle had increased resistance.  Had the rig for 12 years and some time during that period had to replace one of the valves because it was leaking.  Looked all over for a replacement valve with grease zirk.  None could be found.  I then realized the manufacture had installed the zirks.  All that was required was drilling a small hole in the valve and screwing in the zirk.  Valves on our Foretravel are hidden behind a wall so this solution isn't feasible without a lot of trouble.

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Re: Freshwater check valve and greywater plunger issues

Reply #8 – April 25, 2022, 12:38:49 am

No trouble if you modify the wall that hides the valves.

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Re: Freshwater check valve and greywater plunger issues

Reply #9 – June 14, 2022, 12:32:38 am

So much experience and wisdom here.  Saw this post a couple of months ago.  I've been having trouble with binding valves for a while.  Siliconed the plungers and they improved.  Then poured a gallon of Walmart vegetable oil in the shower and toilet drains and they worked even better.  Just wanted to say thank you.  Been passing this home remedy around to all my buddies.     

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