Black and gray holding tank valve replacement

[Gunnerbob59]

Hello,

I have a 2020 Redwood 3991RD and have leak-by on the Gray tank #1 valve. The Black tank Valve is very hard to open and close. So, I plan to replace the (1) black tank valve, and the (2) gray tank valves while I have the belly cover removed and access to all 3 tanks.

I plan on replacing all valves with VALTERRA valves. I believe the black valve would be TC372 (3" valve w/72" cable) and the two gray valves would be TC172 (1 1/2" valve with 72" cable). I tried calling Redwood customer service to confirm valves sizes and cable length only to be told they cannot provide that information, and directed me to Trekwood parts website. Not much help there either.

Question - Can anyone confirm the Black Holding Tank Valve is 3" inch size with a 72" cable? Are the Gray Tank Valves 1 1/2" inch size with 72" cable?

Thanks in advance for your replies and recommendations. Much appreciated!!

Gunner Bob

[travelin' texans]

Originally Posted by Gunnerbob59

Hello,

I have a 2020 Redwood 3991RD and have leak-by on the Gray tank #1 valve. The Black tank Valve is very hard to open and close. So, I plan to replace the (1) black tank valve, and the (2) gray tank valves while I have the belly cover removed and access to all 3 tanks.

I plan on replacing all valves with VALTERRA valves. I believe the black valve would be TC372 (3" valve w/72" cable) and the two gray valves would be TC172 (1 1/2" valve with 72" cable). I tried calling Redwood customer service to confirm valves sizes and cable length only to be told they cannot provide that information, and directed me to Trekwood parts website. Not much help there either.

Question - Can anyone confirm the Black Holding Tank Valve is 3" inch size with a 72" cable? Are the Gray Tank Valves 1 1/2" inch size with 72" cable?

Thanks in advance for your replies and recommendations. Much appreciated!!

Gunner Bob

IIRC There's at least 2 different brands that may have been used, Valterra & Bristol, don't recall if they're interchangeable. I'd verify before purchasing replacements. You'll only need the the blade assembly with seals, not the entire valve, doubt there's enough piping to be able to cut the old out & reinstall new.
Also I believe the cables are universal 6' & cut to fit. May not need cables either, rerouting for a straighter route & lubrication may be all that's needed.
Don't quote me on any of this information, confirm for yourself.
Also recommend shopping around for the valves from other sources, from my experience Trekwood is absolutely ridiculously high on their shipping charges. Might try E Trailer, PPL or United Rv, even CW may be cheaper.

[travelin' texans]

Originally Posted by Gunnerbob59

Hello,

I have a 2020 Redwood 3991RD and have leak-by on the Gray tank #1 valve. The Black tank Valve is very hard to open and close. So, I plan to replace the (1) black tank valve, and the (2) gray tank valves while I have the belly cover removed and access to all 3 tanks.

I plan on replacing all valves with VALTERRA valves. I believe the black valve would be TC372 (3" valve w/72" cable) and the two gray valves would be TC172 (1 1/2" valve with 72" cable). I tried calling Redwood customer service to confirm valves sizes and cable length only to be told they cannot provide that information, and directed me to Trekwood parts website. Not much help there either.

Question - Can anyone confirm the Black Holding Tank Valve is 3" inch size with a 72" cable? Are the Gray Tank Valves 1 1/2" inch size with 72" cable?

Thanks in advance for your replies and recommendations. Much appreciated!!

Gunner Bob

IIRC There's at least 2 different brands that may have been used, Valterra & Bristol, don't recall if they're interchangeable. I'd verify before purchasing replacements.
Also I believe the cables are universal 6' & cut to fit.
Don't quote me on either of this information, confirm for yourself.

[Ford truck guy]

I also have a 2020 3991RD.. I had mine at a small repair shop last year to have my 3 replaced.. The guy ( who has done work for me in the past ) said that he would not do it as the black tank would need to be dropped to REPLACE THEM..

I called another small repair shop and I asked them to replace the valves… Made the appointment, dropped off the Redwood. They called my later that morning to tell me they dropped the belly pan and lubed the valves and they would not be replacing them.

They have worked just fine after he lubed them….

[Gunnerbob59]

Originally Posted by Ford truck guy

I also have a 2020 3991RD.. I had mine at a small repair shop last year to have my 3 replaced.. The guy ( who has done work for me in the past ) said that he would not do it as the black tank would need to be dropped to REPLACE THEM..

I called another small repair shop and I asked them to replace the valves… Made the appointment, dropped off the Redwood. They called my later that morning to tell me they dropped the belly pan and lubed the valves and they would not be replacing them.

They have worked just fine after he lubed them….

Ford Truck Guy,

i assume the repair guy drilled a hole in the top of the valve body and sprayed or injected lubricant into the valve assembl? I've thought about doing this, however I have one valve that will not open fully, and when closed, I still have leak by. Thanks for your reply.

[travelin' texans]

As stated earlier, take the basement wall down & check the routing of the cables. Ifound mine had a couple figure 8s in them over & around stuff to take up the extra cable. I was able to loosen it at the the handle in the convenience center & twist a good bit of the loops out of the cable, made the world of difference.
Also I periodically would after dumping the tanks pour about a 1/2 cup of cooking oil in each tank, seemed to also help.

[Gunnerbob59]

Originally Posted by travelin' texans

As stated earlier, take the basement wall down & check the routing of the cables. Ifound mine had a couple figure 8s in them over & around stuff to take up the extra cable. I was able to loosen it at the the handle in the convenience center & twist a good bit of the loops out of the cable, made the world of difference.
Also I periodically would after dumping the tanks pour about a 1/2 cup of cooking oil in each tank, seemed to also help.

Travelin' Texans,

Thanks for all the great advice. I will remove the carpet wall and check the cable routings to ensure they do not have tight bends or loops. I will remove the belly covering and check there too. While under the rig, I will attempt to lubricate the stiff working valves, however I will need to remove gray tank #1 valve to see what could be obstructing it from opening and closing properly. I cannot pull the T-handle out as far as the others, and when it it pushed in closed position, I still get leak-by. Hopefully, with fingers crossed, it will go smooth. Do you or anyone else know if the gray tank #1 is above/below/adjacent to the black tank? I'm not sure of the 3 tanks configuration or how they are mounted. As stated, Redwood customer service and Trekwood were uselesss. Thanks again for your reply.

Gunner Bob

[Ford truck guy]

Drop me your email.... I have 2 drawings for you that I am unable to link up on the site

Joe


joeyd208@gmail.com

[Andover]

Lube the blade seals with Dow Molykote 111