2016 BT Cruiser 5210 spare tire mount and black water flush valve.

[mahnh]

We purchased our RV a month or so ago and decided to camp in the back yard to get familiar with all of the systems. We have a black tank flush valve on the back of the RV. The issue is it’s behind the spare tire. When I went to remove the two locking nuts holding the spare tire the bolts just spun in place. I wound up having to dremel slots in the ends of the studs to hold them from spinning so I could remove the nuts. There is a lose metal 6”x6” steel plate on the bolts that the rim sets on. This design sucks because the tire needs to be removed to flush the system and the studs are not secured to a solid surface. Has any one else experienced this? Or did they just forget to weld the studs on my camper?
The studs just seem to flop around and freely spin but don’t pull out. I think I am going to put nuts to hold them in place on the metal plate. Then I’ll mount the tire. Or I’ll just tack weld the bolt to the plate to prevent them from spinning which may be a better option so the rim sits flat on the plate.

Also the black water flush valve seems to be plugged up. Water would not flow into the tank. Is there a shut off to open the valve? Any suggestions?

 

[Just two]

Yes that is a known problem with the spare tire. I added nylock nuts to hold the bolts captive.

I had a chance to replace the outlets on my 2021 5210 and found the plastic toilet cutout loose in the black tank. I guess it was easier for the factory to just let it drop into the tank.
The first picture is of the cutout from inside the tank. The last picture you can see the metal plate that supports the spare tire bolts. The other pictures are replacing the grey and black tank valves adding a tee and calling it a large grey tank. We use a composting toilet now.

 

[mahnh]

Yes that is a known problem with the spare tire. I added nylock nuts to hold the bolts captive.

I had a chance to replace the outlets on my 2021 5210 and found the plastic toilet cutout loose in the black tank. I guess it was easier for the factory to just let it drop into the tank.
The first picture is of the cutout from inside the tank. The last picture you can see the metal plate that supports the spare tire bolts. The other pictures are replacing the grey and black tank valves adding a tee and calling it a large grey tank. We use a composting toilet now.

Thank you so much for the quick response and great information. From your picture I understand why the bolts are so loose but don’t pull through. I feel better about securing them with a couple of nuts.

 

[mahnh]

Have you had any issues with a clogged black water flush valve?
Or do you know if there is a shutoff somewhere?
When I hooked up the hose to flush the blsckwater tank nothing went in. It’s either plugged or the back flow valve shut off.

 

[Just two]

My back flow preventer is on the inside close to the outside connection. I am able to get to it by removing the drawers in the lower kitchen cabinet.. You may be able to see the black valve in the photos attached to the white flex hose. I removed the cabinets to upgrade them. Then I removed the check valve and changed the black tank to gray. We are now using a composting toilet.

 

[mahnh]

Thank you for the prompt response. Yep I see it.
I suspect mine is behind the bathroom vanity or behind the toilet because the inlet is right there. Didn’t want to take the toilet off to solve the spinning spare tire like lug issue because we went on a trip this past weekend. Hopefully the valve is accessible through the opening behind the toilet. That will kill 2 birds with one stone.

 

[Just two]

Good luck with that. I found it easier to remove our camper toilet than the ones in our house. Every time I work on Our Cruiser I learn a lot. This can only help when something breaks while we travel. I appreciate the help that I have found here on this site.

 

[mahnh]

As it turns out the back flow preventer was hooked up backwards from the factory in 2016! The previous owner said she never used it she couldn’t lift the tire. The RV is new to us last year with 4 hours on the generator and 14k miles. I replaced the valve with a new brass one and installed it correctly. I also shifted the spare tire 3” to the left (looking from the back. I had to move the toilet feed line and shift the inside/outside steel plates. I also secured the studs by adding a lock washer on the inside and a locking star washer & nut on the outside of the plate to prevent the bolt from spinning. Now I can access the black water clean out valve without removing the spare tire. The spare tire bolts no longer spin when removing the nuts.

 

[Just two]

As it turns out the back flow preventer was hooked up backwards from the factory in 2016! The previous owner said she never used it she couldn’t lift the tire. The RV is new to us last year with 4 hours on the generator and 14k miles. I replaced the valve with a new brass one and installed it correctly. I also shifted the spare tire 3” to the left (looking from the back. I had to move the toilet feed line and shift the inside/outside steel plates. I also secured the studs by adding a lock washer on the inside and a locking star washer & nut on the outside of the plate to prevent the bolt from spinning. Now I can access the black water clean out valve without removing the spare tire. The spare tire bolts no longer spin when removing the nuts.

Nice job. You really went the extra mile getting it right.

 

[Just two]

I combined both waste tanks. We use a composting toilet so a black tank isn’t needed. When I removed the waste gates, I flushed both tanks. The black tank had a 2 1/2” hole saw slug in it. I believe it is from the GS factory. I could only imagine what that would have done if it made it’s way to the gate valve?

 

[Ronald1955]

As it turns out the back flow preventer was hooked up backwards from the factory in 2016! The previous owner said she never used it she couldn’t lift the tire. The RV is new to us last year with 4 hours on the generator and 14k miles. I replaced the valve with a new brass one and installed it correctly. I also shifted the spare tire 3” to the left (looking from the back. I had to move the toilet feed line and shift the inside/outside steel plates. I also secured the studs by adding a lock washer on the inside and a locking star washer & nut on the outside of the plate to prevent the bolt from spinning. Now I can access the black water clean out valve without removing the spare tire. The spare tire bolts no longer spin when removing the nuts.

Our 5230 (2022) had a loose spare tire, and I found the bolts would spin. So I now keep a 1/2 breaker bar socket and extension to tighten or loosen the spare tire plus a wrench to hold the bolts. We had also installed a larger ceramic toilet with a shut off valve at the toilet. We have access to the bolts.

 

[Just two]

R1955 you should add the nylock nuts on your spare tire bolts or lock washer, like MAHNH did. I added nylock nuts on the metal plate behind the toilet, this makes removing the spare easy. A one person job.

Pro tip. You can strap a bottle jack in the spare tire. It’s a nice place to store it. Storage space is a premium.

 

[Ronald1955]

I will consider doing that with Nylock, as for a jack, I would also need coveralls, knee pads, boots to change a tire. We have Road Service. Plus age 71 limits what I can do. I was an equipment mechanic
For 46 years. Thank You.

 

[Just two]

I will consider doing that with Nylock, as for a jack, I would also need coveralls, knee pads, boots to change a tire. We have Road Service. Plus age 71 limits what I can do. I was an equipment mechanic
For 46 years. Thank You.

True, Road Side service is nice. Enjoy traveling.

 

[mahnh]

R1955 you should add the nylock nuts on your spare tire bolts or lock washer, like MAHNH did. I added nylock nuts on the metal plate behind the toilet, this makes removing the spare easy. A one person job.

Pro tip. You can strap a bottle jack in the spare tire. It’s a nice place to store it. Storage space is a premium.

Great idea with the bottle jack. We just got back from the trip to PA and VA with no jack! We have roadside assistance etc. but I did not like not having the option of changing a tire myself.

 

[mahnh]

Nice job. You really went the extra mile getting it right.

Thanks. We are getting older and although I can still lift the spare tire by myself not sure how much longer I will be able to. I figure now is the time to get things right. Additionally, the previous owner never used the black water tank flush valve because she definitely couldn’t remove the spare. The valve works the nuts. We were putting a hose in the toilet to add a few gallons to the black water tank.
We just went on our first big trip about 2000 miles and as we were driving we had water trickling from under the kitchen sink cabinet. I meticulously inspected all the plumbing under there and it was bone dry. When we got back I pulled the jack knife seat out to expose the water tank. Turns out the air vent tube on top of the tank came off the nipple with the screen on it located by the water fill. The hose dropped down low and the sloshing water while driving leaked out of the hose. The reason was because the hose clamp that GS used was too big and didn’t tighten on the fitting. I replaced it with a smaller clamp problem solved no more water. I am putting a trap door in over that area of the water tank for easy inspection of all the fittings and water inlet. All of the fittings coming out of the tank were lose they just used a ton of Teflon tape to prevent leaks. I tightened them down as well. I like the GS design overall but wish they would pay more attention to detail during assembly.

 

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Have you had any issues with a clogged black water flush valve?
Or do you know if there is a shutoff somewhere?
When I hooked up the hose to flush the blsckwater tank nothing went in. It’s either plugged or the back flow valve shut off.

Your valve could be hooked up backwards, you may just need a new valve, better yet you may have some mud dobbers that built a little home in your hose.