Black tank blade valve.

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8Muddypaws

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Hard to believe that with all my years of RV experience I have never replaced a black tank blade valve. From watching YouTube videos it seems that everybody has a hard time spreading the pipes apart enough to get the new valve into position without knocking the seals out of place.

Anybody have a foolproof method? (I'm the fool doing the job in this case)
 
Use plumbers grease on the O rings to hold them in place. As to spreading the flanges apart, without seeing that plumbing I can't say for sure. If that 3" waste line is straight for at least a foot or more, You might be able to use a woodworking spreader/clamp and a block of wood fastened on each side of the valve flanges with large radiator clamps. to spread the flanges apart enough to easily insert the new valve and loosely install the bolts before releasing the spreader/clamp. (top view)
1679889942739.png
 
I was kind of thinking along those general lines. Thanks.
Or if that doesn’t work, you may be able to cut the pipe down stream someplace, repair the valve then connect the two pipes with a rubber sleeve held on with hose clamps. You can get them at Lowe’s or Home Depot. Then if you ever have to do it again, it will be a breeze.just make sure you remove all the burrs inside the pipe caused by cutting.
 
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When I did mine, I flushed both the tanks several times. Then, when I got home and started to work I used the leveling jacks to raise the driver's side of the coach. That way, any residual ran to the back of the tank away from the drain. I think I got less than a cup of liquid out of each tank when I took the valves apart.
 
Or if that doesn’t work, you may be able to cut the pipe down stream someplace, repair the valve then connect the two pipes with a rubber sleeve held on with hose clamps. You can get them at Lowe’s or Home Depot. Then if you ever have to do it again, it will be a breeze.just make sure you remove all the burrs inside the pipe caused by cutting.
I believe these are commonly called a Fernco coupling. The rubber won't hold up to UV of sunlight but it will be in the shade of the RV for its life so it should last a while. The better models have a piece of aluminum that wraps over the rubber for protection and strength
 
I think it might already have a coupling on the pipe. That might make it easier. Who knows, it might be easier than I expect? (Nah, my luck doesn't run that way in spite of being mostly Irish)

I was already planning on raising the rear end to completely empty the black tank, lowering it and raising the front while I work on it.

The old valve leaks.

I'm going to start the job right after lunch. Eating lunch right afterwards does not sound very appetizing.

Thanks for all the great advice Y'all.
Russ
 
It went OK. I tried pushing the pipes with my hands. Nope, that didn't work. After wrestling with it for 30 minutes I cut a piece of 3/4" PVC pipe to the distance between the two tanks + 1/2". I wedged it between the tanks and the valve practically fell out. The tanks are quite flexible.

Installing the new one was easy enough thanks to a small neodymium magnet that held the nut in the socket while I got it started on the bolt. Good thing I have a short ratchet and a pretty decent tool kit from my motorhead and motorcycle days.

I put a few gallons of water in the black tank and so far there hasn't been so much as a single drop leak.

OK, so here's where that 'Luck O' The Irish' curse got me.
One of my Atwood Levelegs jacks bit the big one as a result of all this up & down activity. I suppose I should be relieved that it happened at home and not on the road. It's the left front. It's a 66302 7.5K 13" and so far I've found used ones for about $1200 and rebuilt ones for about $1500 after the core charge.

Yeah, I know the Jack would have failed anyway. But it makes a good RV story doesn't it?
 
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I would look for a. Hydraulic piston repair facility. There is nothing to those rams . Just 2 or 3 three o rings and maybe a quad seal. As long as the cylinder wall is no scored. It should take no longer than a couple of hrs to rebuild and 1 hour for testing. Cost may end up being $300.00 or so.
 
I may have been mistaken but thought I read once that the motor of the Atwood jacks can be rebuilt. If so, it's a whole lot cheaper than trying to find another unit.
 
It's not the motor. The motor spins (and spins and spins). It's either the clutch mechanism, a stripped gear, or a sheared pin. I've heard rumors that they can be repaired but have never found the parts. I took the first one that failed apart and tried to find parts for it but struck out. This one is our third.

If anybody has information about how to repair these I'd appreciate a heads up.

it's a mechanical gear driven system, not hydraulic.
 
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Being a mechanical guy who likes to learn new mechanical things, and having replaced a couple blade valves on RV tank drains before, I don't understand what you mean by "spreading the pipes apart". A blade valve is just a mechanical valve on the end of a pipe. You pull it open to drain, and push it shut to close it again. What motor would be involved?

Blade valve:
61rUo5gqTVL._AC_UF894,1000_QL80_.jpg
 
Being a mechanical guy who likes to learn new mechanical things, and having replaced a couple blade valves on RV tank drains before, I don't understand what you mean by "spreading the pipes apart". A blade valve is just a mechanical valve on the end of a pipe. You pull it open to drain, and push it shut to close it again. What motor would be involved?

Blade valve:
61rUo5gqTVL._AC_UF894,1000_QL80_.jpg












He was kanting the tanks so the contents wouldn't flow. The leveling jack went kaput. Errantly conflating Irish ancestry with Irish ancestry while half enebriated. The latter being necessary to invoke the luck.
 
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Being a mechanical guy who likes to learn new mechanical things, and having replaced a couple blade valves on RV tank drains before, I don't understand what you mean by "spreading the pipes apart". A blade valve is just a mechanical valve on the end of a pipe. You pull it open to drain, and push it shut to close it again. What motor would be involved?

Blade valve:
61rUo5gqTVL._AC_UF894,1000_QL80_.jpg
Being a mechanical guy who likes to learn new mechanical things, and having replaced a couple blade valves on RV tank drains before, I don't understand what you mean by "spreading the pipes apart". A blade valve is just a mechanical valve on the end of a pipe. You pull it open to drain, and push it shut to close it again. What motor would be involved?

Blade valve:
61rUo5gqTVL._AC_UF894,1000_QL80_.jpg
Read post #10.
 
Read post #10.
I did...it says, "I cut a piece of 3/4" PVC pipe to the distance between the two tanks + 1/2". I wedged it between the tanks and the valve practically fell out. The tanks are quite flexible."..."Installing the new one was easy enough thanks to a small neodymium magnet that held the nut in the socket while I got it started on the bolt."

What does any of that have to do with replacing a manual blade valve? It's one valve on the end of one pipe...it's literally like a 10-minute job.
 
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