Thursday, February 1, 2018

Dirty Deed is Done, AND IT WAS …

At home in Holiday/Tarpon Springs area

Finished Pump Assembly rebuild

Well, there is the rebuilt Vacuum Generator Motor Assembly.  It was a dirty job…but not as “BAD” as I had anticipated (smell and fluid wise), but it was difficult due to the tight squeeze (lack of space to work in) and the heavy calcium build up (yuck!).  After getting it apart, I had difficulty getting the main bolt off which connects the motor and the billow.  I had to buy those two tools on the table above…seems like every RV job adds to my tool collection (unless it is done at Arny’s because he has 3 of EVERYTHING!)  And yes Arny, that  is a 3/4 open end on one side, and closed ratchet on the other.  Hot smile  Once home, I had it all apart lickety-split.

YUCK!The picture to the left is purposefully small…but if you click on it it is larger, but why anyone would want to do that is beyond me.  The only reason I included it was to show the brown calcium build-up that I had to deal with.  There are FOUR duck bills, and they were AWFUL!  I don’t know how anything was passing through the old duckbills…and they were all hard to pull out due to the calcium build up around them.  DuckbillIt took a lot of lime-away type of cleaner to get the calcium out of the cylinder chamber and out of the pipe areas. I also found that to replace the duck bills in the future, I will have to remove the entire Motor Assembly (all that in the first picture)..but I won’t have to take the motor assembly apart, just remove it….this is probably why the duck bills have not been done for who knows how long.)

Pump Assembly, back side showing billows

Here is the other side of the assembly, and you can see the billows, and that large bolt holding it to the motor.  When you try to turn the bolt to take it off, the whole motor turns…which is why I needed that clamp thingy to hold the shaft on the other side of the billow....which worked, the bolt loosened right up.  As this motor turns, the billow goes up and down.  Up brings fluid (and solids) from the vacuum tank…solids are broken up as they pass through the duckbills, and as the motor pushes the billows down, it pushes the mixture through to the black tank.  The duckbills will close on the intake side as the billows goes down, and on the exit side as the billows come up, hence, allowing the mixture to move only in one direction.  After a minute or two, it builds up a vacuum in the vacuum tank…and when you flush, a lot of mixture pushes right through the cylinder chamber to the black tank, the rest of it is pumped as the billows go up and down.

Scratches on arm from working in confinded space

All of these pictures were taken with my cell phone, except the duck bill (above) and the picture below, both of which I got off the Internet.  Above is my arm…the hazards of working in a very tight space.  This was before re-installing it, and it even looks worse now.  Amazingly, the right arm hardly has a scratch. 

Vacuum Pump Rebuild Parts

TWO ISSUES:  I showed the picture above, less the arrow, in a previous blog.  When I put the  motor assembly back together again, I did not get these clamps (red arrow) on correctly.  The beveled end actually faces down, not up.  When they are up, the billows will “seem” to be set correctly, but as soon as you move the motor and add compression, the billow will pop down, hitting the bottom of the cylinder.  The directions are vague on this, and I should have researched the Internet again right before I put those on.  But THANK GOODNESS I tested it before I put it back into the RV, and it was not that hard to take apart and put them in the right way…which holds the billows in place.  WOW, this new motor and billows are much quieter than the old ones.

The second issue is that I have a leak.  When I was at HomeDepot, the person in plumbing gave me the wrong washer for that white pipe shown in the first picture.  So tomorrow (or one of these days when I can bend over and reach into that small compartment) I will need to take the white pipe off, get it over to a nearby Ace Hardware, and get the right washer.  Not looking forward to that…but it needs to be done.

One GOOF:  As I was trying to unloosen the back left bolt holding the assembly in place on the vacuum tank...I dropped the wrench...which went down to the back side of the vacuum tank.  It was easy to get to once I had the pump assembly pulled out, and thank goodness I was able to use a ratchet on the other back bolt...but the ratchet would not work on this once due to the confined space.  By chance, I tried to turn the bolt with my bare hand...and it turned.  I think this is what messed up my left arm so much....


  1. Sounds like a very yucky job. Hope you really sanitized your wounds.. Who knows what germs were lurking in there.

    1. First washed with hot water and dawn, then sprayed with hydrogen peroxide, then Marcia said to pour original Listerine over my kills everything!

  2. Glad you survived your task. Now you can advise others how to do it.
    Keep those wounds clean.
    Be Safe and Enjoy!

    It's about time.

    1. Yes, I tried to document it in blog a bit, and I would certainly advise anyone who contacted me. Arm is fine, mostly scrapes and bruising. Thanks...

  3. That does not sound like fun AT ALL! I would have taken it to a repair shop. Course I wouldn't have a clue how to do it in the first place. A job well done!!!

    1. Not very many RV Repair centers would have seen a system like this...more found in boats than RVs. When I first saw my arm I thought about you and the bush you had a fight with. :)


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