replacing dump valves on 2551

I need to replace both Auto Drain mechanisms and I think that the black tank valve doesn't seal shut. It is also very stiff to operate manually. I want to install new valves at the same time I do the Auto Drains.

  My question is: do the valves just slip out after removing the four bolts, and are there any tips or tricks to doing this job on a 2551?
 
Thanks in advance!
Dougn

I had to replace the black valve on my 2551.  No, they don't just slip out.  The valve itself is between the flanges that you remove the 4 bolts.  The valve has about a 1/4" rim on either side that will require you to separate the 2 flanges by about 1/2". There are 2 rubber gaskets on either side of the valve. 

So, it depends on how much play you have in the 3" black ABS lines going into the flanges.  On my 2551, it was a real pain because I have the new turbo maserator and the waste lines for both gray and black tanks were fully glued at all joints.  Very little give.   Your 2551 will have the old style maserator and separating the flanges after pulling those bolts may be easier.

Don

Mine slipped right out with old Macerator.

I know its a 2350, but on mine I found quickly that if I removed BOTH valve's attaching bolts, and disconnected the macerator wires, the whole system came off  and was easy to do clean and prep. Assembled the gray one, installed bolts loosely, did the black one, then tightened all.  Hope that helps when doing a 2551   

What Volk said, drop the entire section. It’s not a bad job if you don’t have to fight it and this way you dont