Sewer connection too low

G

Greg C.

Active member
Oct 11, 2019
256
23
28
My new to me coach has multiple issues, so I will post one at a time and ask for opinions on how to remedy.

My sewer connection is extremely low and towards the back. I don't know if this is an original black tank or a replacement. One of the PO's put this
cobbled up skid bar on it to protect it, but I'm dragging everywhere I go. The picture below shows some space forward where I may be able to
straighten out the 3" some and get the assembly farther away from the bumper.

"]http://www.gmcmhphotos.com/photos/data/7310/medium/IMG_20200714_084904156_HDR.jpg]

Check out the seat belt mounting straps. They seem to work...

[url]"]http://www.gmcmhphotos.com/photos/data/7310/medium/IMG_20200714_084812782.jpg][url]

I have seen pictures on the photo site where some folks have a macerator that appears to be mounted above the plane of the sewer outlet pipe. Did I
see that right? The macerator will suck upwards enough to evacuate the tank like that? If so, that may be an option for me.

I would even come out the back if that would work better in this case. But I have to do something as there are a lot of campsites I can't back into
with this skid bar situation. Worst case, I can weld up some rollers and mount them.

What would you do?

Thanks in advance!
--
Greg Crawford
Knoxville, TN

1977 Royale, rear bath
Quad bags, brand unknown
 
I am not familiar with royale that you have. they had some different plumbing so I can't say if that is stock or not.

macerator needs to be mounted downhill. it will not suck things that flow away from it's inlet. but the macerator does pump it uphill.

the gmcmhphoto site should have some photos of how to install. or call JimK with applied GMC to see what they do about royales.

www.gmcmhphotos.com

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
 
Greg,

Your sewer outlets and valve handles are definitely too low -- there's no
reason other than poor plumbing replacement -- you should be able to move
them upward at least a couple of inches if not more -- hard to tell in a
photo. I've always mounted my macerators above the bottom of the frame,
but horizontally so that there's gravity flow from the tanks into the pump
inlet. But, I have seen some of them mounted vertically, between the rear
crossmember and the bumper; they reportedly work well (I'm skeptical about
that last little bit in the pipe though). For whatever it may be worth,
here's my long-since replaced installation which I used for 10+ years:
http://www.gmcmhphotos.com/photos/birchaven-macerator/p360.html

I've since redesigned the system with a second macerator to serve only the
gray water tank, which is mounted on Coachmen-built coaches, about where
the GMCs' consolidated tank's located. The outputs of the gray and black
macerators tee into a common 15' drain hose stowed along the left side of
the frame in a piece of the commonly seen fiber-optic conduit.

One modification I've particularly enjoyed is the addition, at the
behind-the-license-plate location, of switches which allow me to lower or
raise the rear of the coach for completely draining the tanks. Added
valves at the air bags and a high-capacity 120vac compressor let me lower
and raise quickly at the dump stations. If I had a vertically mounted
macerator, I'd consider that feature mandatory.

I almost forgot that I'd posted this album for now deceased Dan Hudson:
http://www.gmcmhphotos.com/photos/g4433-dan-hudson-5c-27s-23-5c-27-macerator-installation.html

That's also a Birchaven, but they're both like a rear bath Royale.

Ken H.

On Thu, Jul 16, 2020 at 4:03 PM Greg Crawford via Gmclist <

> My new to me coach has multiple issues, so I will post one at a time and
> ask for opinions on how to remedy.
>
>
> My sewer connection is extremely low and towards the back. I don't know if
> this is an original black tank or a replacement. One of the PO's put this
> cobbled up skid bar on it to protect it, but I'm dragging everywhere I go.
> The picture below shows some space forward where I may be able to
> straighten out the 3" some and get the assembly farther away from the
> bumper.
>
> http://www.gmcmhphotos.com/photos/data/7310/medium/IMG_20200714_084904156_HDR.jpg
> ]
>
> Check out the seat belt mounting straps. They seem to work...
>
> [url"]http://www.gmcmhphotos.com/photos/data/7310/medium/IMG_20200714_084812782.jpg][url
> ]
>
> I have seen pictures on the photo site where some folks have a macerator
> that appears to be mounted above the plane of the sewer outlet pipe. Did I
> see that right? The macerator will suck upwards enough to evacuate the
> tank like that? If so, that may be an option for me.
>
> I would even come out the back if that would work better in this case. But
> I have to do something as there are a lot of campsites I can't back into
> with this skid bar situation. Worst case, I can weld up some rollers and
> mount them.
>
> What would you do?
>
> Thanks in advance!
> --
> Greg Crawford
> Knoxville, TN
>
> 1977 Royale, rear bath
> Quad bags, brand unknown
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
I am not 100% sure but I believe the common macerator has a spec of
'self priming up to 48 inches' which I will be verifying (although not
trying for anywhere near 48") prior to installing the one I purchased
(Jabsco #18590).

YMMV of course. I am hoping I get some 'lift' in the sewer line with the
macerator otherwise mine will be dragging on the ground to get enough
drop to stay primed :)

Stu

> I am not familiar with royale that you have. they had some different
> plumbing so I can't say if that is stock or not.
>
> macerator needs to be mounted downhill. it will not suck things that
> flow away from it's inlet. but the macerator does pump it uphill.
>
> the gmcmhphoto site should have some photos of how to install. or
> call JimK with applied GMC to see what they do about royales.
>
>
>
> www.gmcmhphotos.com
 
Thanks for the replies and the information.

Ken, I can't raise the piping any because there is currently little to no fall out of the tank. If I raise the piping, it will be higher than the tank
outlet.

That's why I thought I may be able to move things forward toward the wheels and gain a little clearance when going through dips.

It seems like this black tank may be a replacement, but hopefully someone with a Royale rear bath will see the pictures and chime in.

Thank you.
--
Greg Crawford
Knoxville, TN

1977 Royale, rear bath
Quad bags, brand unknown
 
Guess why I have the rapid up-down mod?

Ken H.

On Thu, Jul 16, 2020 at 8:54 PM Greg Crawford via Gmclist <

> Thanks for the replies and the information.
>
> Ken, I can't raise the piping any because there is currently little to no
> fall out of the tank. If I raise the piping, it will be higher than the tank
> outlet.
>
> That's why I thought I may be able to move things forward toward the
> wheels and gain a little clearance when going through dips.
>
> It seems like this black tank may be a replacement, but hopefully someone
> with a Royale rear bath will see the pictures and chime in.
>
> Thank you.
> --
> Greg Crawford
> Knoxville, TN
>
> 1977 Royale, rear bath
> Quad bags, brand unknown
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Due to my mounting limitations - my Jabsco is mounted above the tank and
primes/pumps just fine. I likely leave more in the tanks than an ideal
situation - but it's so easy to dump with the macerator, I'm not really
very worried about it.

I'd obviously prefer it to be lower - but it is what it is. I was
concerned with protecting the pump and am happy with its performance.

My Jabsco manual states: "The JABSCO macerator is self-priming to a five
foot lift when impeller is wet, four foot when dry".

Rob
Victoria, BC
76 Royale - Rear Twins/Dry Bath

>
> I am not 100% sure but I believe the common macerator has a spec of
> 'self priming up to 48 inches' which I will be verifying (although not
> trying for anywhere near 48") prior to installing the one I purchased
> (Jabsco #18590).
>
> YMMV of course. I am hoping I get some 'lift' in the sewer line with
> the macerator otherwise mine will be dragging on the ground to get
> enough drop to stay primed :)
>
> Stu
 
Larry: Now that I have seen what a Royale is supposed to look like in yours, I can say that the black tank on mine is a replacement. It runs longways
with the coach, not athwartship like yours. My outlet comes out of the side of the tank at the extreme rear end.

This explains why mine is so low as the tank protrudes rearward past the point where the rear frame section slopes upward, making the tank the lowest
point there.

I really like the way you have done your macerator. Very neat and clean. Too bad mine is so different. I'll have to engineer something else for it.

Thank you for the reply.
--
Greg Crawford
Knoxville, TN

1977 Royale, rear bath
Quad bags, brand unknown
 
> Larry: Now that I have seen what a Royale is supposed to look like in yours, I can say that the black tank on mine is a replacement. It runs
> longways with the coach, not athwartship like yours. My outlet comes out of the side of the tank at the extreme rear end.
>
> This explains why mine is so low as the tank protrudes rearward past the point where the rear frame section slopes upward, making the tank the
> lowest point there.
>
> I really like the way you have done your macerator. Very neat and clean. Too bad mine is so different. I'll have to engineer something else for
> it.
>
> Thank you for the reply.

Greg,
That is not what my grey tank looked like when I got the coach. Here is my story.

When we first got our coach, I noted that we had this black tank smell about the coach. Got to looking under the coach and saw a huge 1/4” steel
plate completely covering the black tank and most of the plumbing associated with it. I took that plate down only to find a plumbers nightmare put
together by the PO, and a black tank broken across the top of the tank. I decided that a new tank with a macerator would simplify this whole thing.
I would have to remove all of the existing plumbing and redesign the system to include the macerator. So I got a big empty pan and pulled the gate
valves to empty the two sewer tanks. Nothing came out so the tanks appeared empty. With that knowledge, I raise the coach up on ramps, crawled under
there, laying on the ground with a saws-all to just cut all of the plumbing out. Half way through, a small leak, all of the way through the pipes fell
and dumped about 5 gallons of black tank “stuff” on me. My first shower of the day. :( Later after my second real shower, I got to looking at
the gate dump valves and found the system plugged up just up stream of the gate. I replaced all of the stuff I cut out of the system with what you see
in my Macerator install post.

There is a lesson to be learned here....I'll let you decide what ;)
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
 
Early in my GMC experience, a good customer brought his coach to me for a
lesson in operating the valves on his sewer tanks. I turned on the tank
fill gages and it registered full on both tanks. He had just had the coach
worked on at Camping World and they claimed that the tanks were drained.
So, I got out my CSI light, turned off the pump, and shined my light down
the toilet. Sure enough, the tank was brim full. So I had him return to
Camping World and have them empty the tanks they said were empty. So, he
did, and returned in a couple of days saying that Camping World claimed
that they had drained the tanks. Well, l checked down the toilet again,
still full. Sent him back to camping world again. They pulled the levers on
the tanks, and nothing came out of the drain, so they exclaimed that the
tanks must be empty. He told them to look down the toilet. Which they
reluctantly checked, and found it full. An argument ended with Paul taking
the coach. Tanks full, he brought it to me. So, I jury rigged a mascerator
pump with a pick-up that would fit down the toilet and hooked up to a
garden hose that I ran to my septic tank. Pumped it out, and dumped a bunch
of bleach water into the tank, and took the coach for a drive on country
roads. Pumped them again. Crawled under the coach, found broken cable to
the valve. Pulled on the broken stub, no joy. Frozen solid. Drilled a hole
in the opposite side of the tank valve, put a punch in the hole and beat on
it until it moved. Nothing drained out. So, I crawled under the coach with
my trusty sawzall. Same thing happened to me. Got a bath in crap water. The
drain lines were full. Made a hell of a mess in my shop. Stinky stuff.
Vowed then and there to NEVER MESS with another black tank that had been
used. I haven't, either. I will replace whole systems, with new stuff, but
that's it.
Jim Hupy
Salem, Oregon

On Sat, Aug 1, 2020, 6:09 PM Larry via Gmclist
wrote:

> > Larry: Now that I have seen what a Royale is supposed to look like in
> yours, I can say that the black tank on mine is a replacement. It runs
> > longways with the coach, not athwartship like yours. My outlet comes out
> of the side of the tank at the extreme rear end.
> >
> > This explains why mine is so low as the tank protrudes rearward past the
> point where the rear frame section slopes upward, making the tank the
> > lowest point there.
> >
> > I really like the way you have done your macerator. Very neat and clean.
> Too bad mine is so different. I'll have to engineer something else for
> > it.
> >
> > Thank you for the reply.
>
> Greg,
> That is not what my grey tank looked like when I got the coach. Here is
> my story.
>
> When we first got our coach, I noted that we had this black tank smell
> about the coach. Got to looking under the coach and saw a huge 1/4” steel
> plate completely covering the black tank and most of the plumbing
> associated with it. I took that plate down only to find a plumbers
> nightmare put
> together by the PO, and a black tank broken across the top of the tank. I
> decided that a new tank with a macerator would simplify this whole thing.
> I would have to remove all of the existing plumbing and redesign the
> system to include the macerator. So I got a big empty pan and pulled the
> gate
> valves to empty the two sewer tanks. Nothing came out so the tanks
> appeared empty. With that knowledge, I raise the coach up on ramps,
> crawled under
> there, laying on the ground with a saws-all to just cut all of the
> plumbing out. Half way through, a small leak, all of the way through the
> pipes fell
> and dumped about 5 gallons of black tank “stuff” on me. My first shower of
> the day. :( Later after my second real shower, I got to looking at
> the gate dump valves and found the system plugged up just up stream of the
> gate. I replaced all of the stuff I cut out of the system with what you see
> in my Macerator install post.
>
> There is a lesson to be learned here....I'll let you decide what ;)
> --
> Larry
> 78 Royale w/500 Caddy
> Menomonie, WI.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
Greg, Typical error bt aRV shop that does know much about the GMC.
Yes it seems to be about 3" too low.
Youll need to take some pics and relay them to me so I can show you or your
shop how to do it.

On Sat, Aug 1, 2020 at 8:03 PM James Hupy via Gmclist <

> Early in my GMC experience, a good customer brought his coach to me for a
> lesson in operating the valves on his sewer tanks. I turned on the tank
> fill gages and it registered full on both tanks. He had just had the coach
> worked on at Camping World and they claimed that the tanks were drained.
> So, I got out my CSI light, turned off the pump, and shined my light down
> the toilet. Sure enough, the tank was brim full. So I had him return to
> Camping World and have them empty the tanks they said were empty. So, he
> did, and returned in a couple of days saying that Camping World claimed
> that they had drained the tanks. Well, l checked down the toilet again,
> still full. Sent him back to camping world again. They pulled the levers on
> the tanks, and nothing came out of the drain, so they exclaimed that the
> tanks must be empty. He told them to look down the toilet. Which they
> reluctantly checked, and found it full. An argument ended with Paul taking
> the coach. Tanks full, he brought it to me. So, I jury rigged a mascerator
> pump with a pick-up that would fit down the toilet and hooked up to a
> garden hose that I ran to my septic tank. Pumped it out, and dumped a bunch
> of bleach water into the tank, and took the coach for a drive on country
> roads. Pumped them again. Crawled under the coach, found broken cable to
> the valve. Pulled on the broken stub, no joy. Frozen solid. Drilled a hole
> in the opposite side of the tank valve, put a punch in the hole and beat on
> it until it moved. Nothing drained out. So, I crawled under the coach with
> my trusty sawzall. Same thing happened to me. Got a bath in crap water. The
> drain lines were full. Made a hell of a mess in my shop. Stinky stuff.
> Vowed then and there to NEVER MESS with another black tank that had been
> used. I haven't, either. I will replace whole systems, with new stuff, but
> that's it.
> Jim Hupy
> Salem, Oregon
>
>
> On Sat, Aug 1, 2020, 6:09 PM Larry via Gmclist

>

> > > Larry: Now that I have seen what a Royale is supposed to look like in
> > yours, I can say that the black tank on mine is a replacement. It runs
> > > longways with the coach, not athwartship like yours. My outlet comes
> out
> > of the side of the tank at the extreme rear end.
> > >
> > > This explains why mine is so low as the tank protrudes rearward past
> the
> > point where the rear frame section slopes upward, making the tank the
> > > lowest point there.
> > >
> > > I really like the way you have done your macerator. Very neat and
> clean.
> > Too bad mine is so different. I'll have to engineer something else for
> > > it.
> > >
> > > Thank you for the reply.
> >
> > Greg,
> > That is not what my grey tank looked like when I got the coach. Here is
> > my story.
> >
> > When we first got our coach, I noted that we had this black tank smell
> > about the coach. Got to looking under the coach and saw a huge 1/4” steel
> > plate completely covering the black tank and most of the plumbing
> > associated with it. I took that plate down only to find a plumbers
> > nightmare put
> > together by the PO, and a black tank broken across the top of the tank. I
> > decided that a new tank with a macerator would simplify this whole
> thing.
> > I would have to remove all of the existing plumbing and redesign the
> > system to include the macerator. So I got a big empty pan and pulled the
> > gate
> > valves to empty the two sewer tanks. Nothing came out so the tanks
> > appeared empty. With that knowledge, I raise the coach up on ramps,
> > crawled under
> > there, laying on the ground with a saws-all to just cut all of the
> > plumbing out. Half way through, a small leak, all of the way through the
> > pipes fell
> > and dumped about 5 gallons of black tank “stuff” on me. My first shower
> of
> > the day. :( Later after my second real shower, I got to looking at
> > the gate dump valves and found the system plugged up just up stream of
> the
> > gate. I replaced all of the stuff I cut out of the system with what you
> see
> > in my Macerator install post.
> >
> > There is a lesson to be learned here....I'll let you decide what ;)
> > --
> > Larry
> > 78 Royale w/500 Caddy
> > Menomonie, WI.
> >
> > _______________________________________________
> > GMCnet mailing list
> > Unsubscribe or Change List Options:
> > http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
> >
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502
 
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