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Plumbing issues

Hey All, just bought a 1989 38' Grand Villa Osh Kosh with a Cat 3208T.  We are super excited to go on our first RV trip tomorrow morning.  This is my first RV purchase and while I'm extremely happy with what we got, I'm finding it's like purchasing a new home for the first time.  There's just things I didn't think to check or test before handing the owner the check.  Tonight, I went to sanitize the holding tank and while it was filling, I noticed water leaking in some places it shouldn't out of the bottom of some frame bolts.  I immediately turned the water off and started to search.  I finally found the culprit.  Under the sofa on the drivers side was a T-off valve and out of that was a very small plastic pipe (similar to what's running to my water filter) that ran into about a foot long 2" PVC pipe capped at both ends and the pipe was threaded into one end.  The cap had broken at one end and water was spilling out onto the floor.  I fixed it by just turning off the valve and all is good.  However, I cannot figure out what in the world this little reservoir is for?  There is only ONE little tube going in and ZERO out.  It looks like it just fills and sits there.  The PVC reservoir was bolted with a U-bracket to the back of the front foot board on the couch.  Does anyone know what this might be?  I can easily build another, but I'm not sure what the purpose is?  Thanks, Benjie.
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #1
Benjie,
Seems like that was a 1st generation surge tank, it just used trapped air without a diaphragm to dampen the the pump surge.. Hopefully James Holder will chime in he is the guru of the classics.

Welcome to the group
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Plumbing issues

Reply #2
My 1989 36' Grand Villa with the ORED chassis has a new pump under the couch but no surge tank. There are two drain valves towards the driver's side wall. We do not notice any surging or "pounding"that would mandate a surge tank so I would recommend you try the system with the tank turned off. Also, look around behind the icemaker for a shutoff valve in the event you have the hot water preheat option. If so, shutting the valve turns the hot coolant off th the water heater but allows it to flow to the dash heater. I mention this because there was no mention anywhere in any of my manuals.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Plumbing issues

Reply #3
Benjie,
Seems like that was a 1st generation surge tank, it just used trapped air without a diaphragm to dampen the the pump surge.. Hopefully James Holder will chime in he is the guru of the classics.

Welcome to the group

Thanks!  I'm pretty sure you're right.  I've replaced the surge tank just in case I needed it!
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #4
My 1989 36' Grand Villa with the ORED chassis has a new pump under the couch but no surge tank. There are two drain valves towards the driver's side wall. We do not notice any surging or "pounding"that would mandate a surge tank so I would recommend you try the system with the tank turned off. Also, look around behind the icemaker for a shutoff valve in the event you have the hot water preheat option. If so, shutting the valve turns the hot coolant off th the water heater but allows it to flow to the dash heater. I mention this because there was no mention anywhere in any of my manuals.

Hmmm, I'll have to check on that.  I noticed two valves under the jack knife sofa, but I have no clue what they're for, do you?  Just shutting off water to the bathroom and kitchen?

I saw a small shutoff valve under the kitchen sink that the former owner had installed when the ice maker was leaking, but haven't been able to look for the preheat option valve yet to see if I have it.  I guess you would want it off in the case where you aren't using the hot water heater?
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #5
Under the couch: one valve is the drain for the hot water. The other is the drain for the cold water. At least this is how my valves were labeled when we bought the coach. Initially too far away to read the small print with my bifocals.
The hot water preheat option valve--in my coach-- is accessed by opening the rollup door below the sink, then reach in to the right, around behind the icemaker and down in a access "hole" cut into the right wall is a blue fretwork knob. This is the control valve for the water preheat valve. We drove from Northern Wisconsin to FOT without heat up front because we did not know about this valve. Wayne, at Fot, can do a show and tell on this. He works in the Alignment Shop at Foretravel.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Plumbing issues

Reply #6
Under the couch: one valve is the drain for the hot water. The other is the drain for the cold water. At least this is how my valves were labeled when we bought the coach. Initially too far away to read the small print with my bifocals.
The hot water preheat option valve--in my coach-- is accessed by opening the rollup door below the sink, then reach in to the right, around behind the icemaker and down in a access "hole" cut into the right wall is a blue fretwork knob. This is the control valve for the water preheat valve. We drove from Northern Wisconsin to FOT without heat up front because we did not know about this valve. Wayne, at Fot, can do a show and tell on this. He works in the Alignment Shop at Foretravel.
I believe my '94 U225 is identical.
1994 U225
build #4514

Re: Plumbing issues

Reply #7
Under the couch: one valve is the drain for the hot water. The other is the drain for the cold water. At least this is how my valves were labeled when we bought the coach. Initially too far away to read the small print with my bifocals.
The hot water preheat option valve--in my coach-- is accessed by opening the rollup door below the sink, then reach in to the right, around behind the icemaker and down in a access "hole" cut into the right wall is a blue fretwork knob. This is the control valve for the water preheat valve. We drove from Northern Wisconsin to FOT without heat up front because we did not know about this valve. Wayne, at Fot, can do a show and tell on this. He works in the Alignment Shop at Foretravel.

You folks are a wealth of knowledge already!  I haven't had a chance to look yet, but will try and read the tags when I run out to the RV this week.  I'm learning that I came into this pretty naive.  I don't think we made a mistake just yet, but I'm realizing these older motorhomes are going to be a little more work than maybe I first realized!  Our first weekend trip turned into a 12 hour nightmare (probably mostly due to my inexperience).  Hoping we're through the rough patches and on to some fun!  My kids want their dad playing with them, not head buried in some plumbing or electrical issue.  Anyway, thanks again!
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #8
Oh, Oh, was I ever wrong!! I just came in from flushing the water system in prep for an outing. Guess what I found under the couch? A white PVC thingee with a tire valve on the top! Now that I know it is a surge tank, or as it is known up here as an anti-hammer air bladder, what should the air pressure be and how/when do I check it?
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Plumbing issues

Reply #9
Check it with water system depressurized(no pump or city water on, one sink valve open) pressure should be 2 psi below rated water pump pressure.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Plumbing issues

Reply #10
Thanks Brett,

Your response then begs another question. How do I check the water pump pressure? I can check the air pressure using a standard tire gauge but how about the pump pressure?
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Plumbing issues

Reply #11
Norm,

There is a discussion of accumulator pressure at Water tank pressure question. It includes the method I used to set up the accumulator on my coach. There are also some alternate suggestions for appropriate pressures.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Plumbing issues

Reply #12
I'm can't remember if my busted hammer reservoir had a valve to read pressure.  I don't think it did, but it was all busted up so I guess it could have.  Is this something I should thread and install?

All I did was cut about an 11" long 3" PVC pipe, cap it at both ends, and then thread it for the water valve that was originally installed in the bottom.
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #13
Norm, I set mine at 29 lbs. I think that is a pretty safe pressure.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Plumbing issues

Reply #14
Kent, help me out here. Do I pressurize the surge tank after draining all water and leaving the drain valves open?

For bzeller: you will need a tire valve stem or equivalent on the top end of your new surge tank in order to introduce air into the tank.

Thanks Kent, Amos. You guys are helping more than just me by providing the info we need.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Plumbing issues

Reply #15
Brett, yes let all of the pressure out of the system to test the tank pressure and set it at the pressure you choose. If you have one of the fancier new high pressure pumps, you may want the tank pressure higher but I am very happy at 29 lbs.
The selected media item is not currently available.Kent Speers
Locust Grove, OK
1993 U300 SSE 40' (Restored at FOT 2009) Build 4323
720 watts Solar
6V92TA DDEC Silver Engine
2014 Subaru Outback

Re: Plumbing issues

Reply #16
Kent, help me out here. Do I pressurize the surge tank after draining all water and leaving the drain valves open?

For bzeller: you will need a tire valve stem or equivalent on the top end of your new surge tank in order to introduce air into the tank.

Thanks Kent, Amos. You guys are helping more than just me by providing the info we need.

OK, I can put one in, but I'm not sure I understand how to pressurize it?  If I drain all the water and leave drain valves open won't I just be be pushing air through empty piping?
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #17
Good morning Kent and Benjie.


Same question as Benjie's. I don't think this surge tank has a rubber bladder in it like the tanks used on wells. So it must just use the air trapped in the PVC tube which is why it is mounted vertically like the ones in the walls of a home.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Plumbing issues

Reply #18
Some pictures would be really helpful.
1994 U225
build #4514

Re: Plumbing issues

Reply #19
Kent, help me out here. Do I pressurize the surge tank after draining all water and leaving the drain valves open?

For bzeller: you will need a tire valve stem or equivalent on the top end of your new surge tank in order to introduce air into the tank.

Thanks Kent, Amos. You guys are helping more than just me by providing the info we need.

OK, I can put one in, but I'm not sure I understand how to pressurize it?  If I drain all the water and leave drain valves open won't I just be be pushing air through empty piping?
It is just like the tank on a well pump in a stick house.  Has a internal rubber bladder and the water only goes into it, not thru it.  It give you water pressure when the pump pressure is low.  Keeps the pump from running all the time.  You need to pump air into that rubber bladder
1994 U225
build #4514

Re: Plumbing issues

Reply #20
I'll take some pics soon.  FYI... I don't have a rubber bladder.  All I had was a small T valve off the main pump line.  The hose is a very small diameter plastic flex hose like you might attach to an ice maker.  At the end of the hose, was a PVC pipe capped on both sides and the hose was threaded into the PVC.  I didn't see the presto valve on mine, but it could have been there since it had basically exploded one end of the PVC cap when I caught it leaking all over.

Nighthawk, would love to see some pics of how yours looks if you get a chance to snap some.
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #21
OK, so here are the pics of what I have now.  The first pic is the T-valve, second is the bottom where it enters the PVC chamber, third and fourth are pics of the chamber side and top.  It sounds like I need to install a pressure valve into the top of the PVC chamber in order to pressurize it.  I'm still not clear on how/when this is done.  I would think you would do this with the water pipes pressurized either by the pump or city water.  If not, then how else will the chamber retain pressure as I'm pumping air in?
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #22
Nighthawk, check it out!  Found them all!

Couple questions.

1. For the cold and hot water drains, where do they drain to?  Back into the holding tank?

2. WRT the water pre-heat valve, it says close for max dash heat.  So if open, it basically helps the water heater be more efficient by not having to use as much propane to heat?
Benjie, Ashley, Zoey, Fallon, and Lake
Round Rock, TX
In search of our next monster...

Re: Plumbing issues

Reply #23
Nighthawk, check it out!  Found them all!

Couple questions.

1. For the cold and hot water drains, where do they drain to?  Back into the holding tank?
On the ground under the coach.  At least that is where it should drain to.  They drain the lower water lines.

2. WRT the water pre-heat valve, it says close for max dash heat.  So if open, it basically helps the water heater be more efficient by not having to use as much propane to heat?
I'll let someone else explain this.  Afraid I'll get tongue twisted and mess it up.
1994 U225
build #4514

Re: Plumbing issues

Reply #24
The gate valve going the water heater, when open, sends engine heated coolant through the water heater as well as through dash heater core.  It is called a motor-aid water heater and will get water in water heater up to full operating temperature-- no propane or electricity needed if you have been driving.

When valve closed, all engine produced hot coolant in that line goes to the dash heater core.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020