Toilet back pressure and shower drain

petarm1 · October 21, 2018, 08:51:11 AM

Good day. I have 2 problems i need a send opinion on, 1st: when flushing the toilet i get serious back pressure, i am thinking the vent is pluged or the area around the vent has serious buildup, what is the best way to fix this,( the prevous owner of my coach did very little maintenance on the holding tanks). 2nd: when showering it seams that i always have to plunge the shower drain to get it to empty but i do not have any problems with any of the sinks.
Any help would be greatly appreciated, thanks

richard5933 · October 21, 2018, 09:05:18 AM

Need a little more information please.

Is this a gravity flush toilet or one of the newer high-tech units? Black tank only or black and gray in separate tanks? Vents to the roof for the black and/or gray? Or some other type of vent?

Etc. etc. Give us a bit more info and it will be much easier to offer suggestions.

Also, what do you mean by 'back pressure' when flushing?

eagle19952 · October 21, 2018, 09:18:11 AM

tank full

?

Dave5Cs · October 21, 2018, 09:27:42 AM

Mexican food?

Astro · October 21, 2018, 09:37:15 AM

In my setup, the black vents through the gray and when gray is nearing full, I get back pressure bubbling through toilet indicating I need to dump gray and clear vent path. Not sure if it is textbook installation, but it works great as early warning alarm.

chessie4905 · October 21, 2018, 11:57:54 AM

With empty tanks, hook a garden hose at the house hot water supply. Run water till good hot water comes out hose. Take hose in to shower drain. Wrap a towel around end of hose which is against drain opening.(towel helps to force hot water into drain without blowing out any plumbing) have someone turn on hot water while you hold this in place. Should dissolve sludge, soap residue out of drain pipe. May take up to a minute. This works great with our kitchen sink drain. You need good hot water.

David Anderson · October 21, 2018, 02:02:01 PM

Sounds like hair in the shower trap. Remove strainer and pick it out with needle nosed pliers.

The toilet is plumbed to the tank in a way it can force liquid to the shower drain easier than to the tank. It would be best to have as straight of a drop to the
tank as possible, ie. minimal turns.

neoneddy · October 21, 2018, 04:22:15 PM

I've got a black tank issue I eventually figured out was from some bad seal or sealing in the squirrel cage blower area.

Essentially, while the bus is running, it's butting a vaccum on the inside. I figured this out because I was getting oder while warming up / airing up the bus. Our toilet doesn't ways seal after a flush, so if it's open up comes the smell. No issues while stationary.

Anyway, make sure your engine compartment fans are not pulling air from.insode the bus.

petarm1 · October 23, 2018, 05:24:52 AM

Black tank seperate from grey tank, black tank vents through the roof, grey tank vents under the kitchen sink.
Regular rv toilet.

richard5933 · October 23, 2018, 05:33:08 AM

Quote from: petarm1 on October 23, 2018, 05:24:52 AM
Black tank seperate from grey tank, black tank vents through the roof, grey tank vents under the kitchen sink.
Regular rv toilet.

With that said, I'd try the usual things first. Remove the vent cap on the roof and make sure that the vent is clear. It doesn't take long for a wasp nest to block a 2" pipe.

The shower I'm guessing is going to be a clogged drain. Hair would be my guess. Try pulling the trap if you have access.