# JB Vacuum Pump Maintenance/Rebuild



## Schroedc

@manbuckwal had his vac pump give it up after ingesting some resin and was debating ordering a new cartridge for the inside and in a moment of boredom I told him to send it to me and I'd give it some new life. I've had this happen before after sucking resin into my pump and/or not changing the oil on a regular basis and I'm cheap so instead of spending 150-200.00 on a new cartridge I prefer to see if they are fixable. I've done several and they run just fine as long as you don't bend up the reed valves and don't put any major scratches in the metal parts. Since a number of folks have one of these I thought I'd show you that it doesn't have to be scary and in a pich might get you back up and running in 30 minutes or so.

Note- I've had these pumps build up resin inside even without sucking liquid resin into them, with a JB pump and a really tight chamber you can draw a full atmosphere of vac and that can cause the resin to boil off or any water still in the wood to boil and that will carry resin vapor into the pump where it hardens darn quick on the hot surfaces inside the pump. 

Here goes on a step by step to clean and reassemble one of these pumps.

First I had Tom remove the cartridge and zip tie it together for shipping to keep the back half from falling off (The screws in the front cover son't hold the entire thing together) this one was so goobered up it wouldn't have made a difference but better save than sorry.





Then I take the cartridge and a file or scriber and draw a line on the side of it so after all the junk is cleaned off of it I know the proper orientation of all the parts.



 

Then remove the two screws and start separating the sections, you may need to use a little persuader action but I would ONLY use a rubber or soft face mallet to avoid wrecking the shaft or gouging anything up



 

This one has nylon vanes in one stage of the pump with a bevel, Take a picture to make sure you get them back in in the right direction. They were a little hard to pull out but not bad, try not to pry on them because if you nick them up you'll need to replace them.






At this point it's ready to start cleaning up, I'm going to soak the parts in solvent overnight so I can remove the metal vanes in the 2nd stage of the pump (They are stuck in there pretty good) 

Tomorrow I'll show the details of cleaning and reassembly.

Reactions: Like 2 | Way Cool 4 | Informative 1


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## manbuckwal

Thanks Colin !!! You da man !!! I'm sure I would have broken something already .


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## Wildthings

So what we are looking at being torn apart is #4 the cartridge? Correct?


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## Schroedc

Wildthings said:


> So what we are looking at being torn apart is #4 the cartridge? Correct?




Correct, The Number 4 part

Reactions: Like 1


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## Schroedc

So the parts all soaked overnight in Lacquer thinner and this morning with some elbow grease I was able to remove the steel vanes in the second stage and get it spinning again. I use only plastic scrapers and if absolutely needed some white scotch brite to clean off all the residue in it. also want to make sure you get into the slots where the vanes ride so they slide in and out easily (In operation they use centrifugal force to move to the outside and create the seal). Here is everything all cleaned up and ready for reassembly. I have a bowl and a disposable brush for some vacuum pump oil to make sure everything is well lubricated as it goes together.



 

First I goober oil on everything including the slots and slide in the vanes (Make sure they slide in and out reasonably easy or you'll need to re-clean the slots to make sure all the residue was removed) They slide all the way in, showing halfway out here so you can see how it goes.





Then I flip it over and while holding the vanes in on the other side with my palm, reinstall the vanes on this side, same rules apply, refer to earlier pictures to make sure they are facing the right way.





Then I place the housings and covers on the pump, using the reference line I scribed in the beginning to make sure it's all facing the right way



 









Then I install the front cover, the two long screws, and some zip ties to hold the back cover on (The screws hold everything together except the back cover, If this was my pump and not shipping it back out I'd skip the zip ties)



 

Now for the valves, When you remove them pay attention to orientation and curvature, if you put them in backwards it ain't gonna work.



 

 

Here is the pump cartridge all back together and ready to ship to @manbuckwal and it should work just fine. This pump had more corrosion inside than I'd seen in some others before but I'm fairly confident it'll run just fine. The other thing I do to make sure it's well lubricated is when I go to refill the pump after it's all assembled is to take a short length of rubber tubing and go from the intake port on the pump into my container of pump oil and fill it that way instead of just pouring it in the fill hole. this makes sure the pump is lubricated and flushes out any crap you might have left in it. Also- I did have one that didn't want to pull a really good vac after cleaning but after I let it run an hour so it improved as the vanes wore in to match the cylinder. Let me know if you have any questions.

Reactions: Like 1 | Thank You! 1 | Way Cool 4 | Informative 1


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## manbuckwal

Awesome, thanks Colin !!!


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## Tclem

If he didn't put the cactus juice in it then it wouldn't have burnt up


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## Final Strut

Tclem said:


> If he didn't put the cactus juice in it then it wouldn't have burnt up



Me thinks Tony is having a very slow day at work.

Reactions: Agree 1


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## manbuckwal

Tclem said:


> If he didn't put the cactus juice in it then it wouldn't have burnt up




Yep ! Good thing I don't have to worry about Stabilizing Olive Burl ..........

Reactions: Like 1


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## Schroedc

manbuckwal said:


> Yep ! Good thing I don't have to worry about Stabilizing Olive Burl ..........



I don't know if Tony is even capable of understanding what to do with it, You should send it to one of us......

Reactions: Funny 3


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## TurnTex

Nice write up! I have done a few myself and had good luck with them. One correction, though...if you are using Cactus Juice, it is NOT the resin that is building up in the chamber as it will NOT boil at full vac and normal working temperatures. In order for Cactus Juice to boil, the temperature of the Juice itself has to be above 94° F at full vacuum. Of course if your Juice temp is that high, you are way past the working temp of 85° F or less. What you are dealing with is natural resins and oils from the wood boiling off and condensing in the pump cartridge. Another reason it is a good practice to dry your wood to 0% before stabilizing. And when I say drying, that means at or above 212° F for 24 hours. Anything less than the boiling point of water will not get the wood to 0%.


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## manbuckwal

TurnTex said:


> Nice write up! I have done a few myself and had good luck with them. One correction, though...if you are using Cactus Juice, it is NOT the resin that is building up in the chamber as it will NOT boil at full vac and normal working temperatures. In order for Cactus Juice to boil, the temperature of the Juice itself has to be above 94° F at full vacuum. Of course if your Juice temp is that high, you are way past the working temp of 85° F or less. What you are dealing with is natural resins and oils from the wood boiling off and condensing in the pump cartridge.



I thimk he meant "boil" in the sense of foaming bubbles, not heat boil .


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## TurnTex

No, he meant boil I am pretty sure! Boiling does not always require heat. Water will boil at room temperature under a full vacuum and it will not be any hotter than it was before. Try it sometime. Put a cup of water in your chamber and pull full vac. If you are getting good deep vac, the water will boil just like it is sitting on your stove top. Boiling is simply the point where a liquid becomes a vapor and is accomplished by adding heat or reducing pressure or both.

Reactions: Agree 1 | Informative 2


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## TurnTex

One other point...there are no known solvents for cured Cactus Juice so if the lacquer thinner cut it, it was not CJ!

Reactions: Informative 1


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## Schroedc

Professional car painter in a past life so I'm familiar with cured resins, while the cactus juice may not dissolve completely you have two bonds, a chemical bond and a mechanical bond with the substrate, in this case the pump parts and since they are fairly polished it's mainly a chemical bond in this case. yes, the cactus juice may not dissolve completely but the penetration of the thinner will cause the bond to fail and the cured resin to become rubbery and start to break down. I use it all the time to clean my drip trays in the oven, pour thinner on top and after an hour it'll just peel off in floppy strips. As far as boiling cactus juice at room temperature, I'll have to shoot a video next time, maybe with a chamber with nothing but juice in it as I can get bubbles forming on the surface long after any bubbles stop coming out of the wood. The other thing is that the bubbles/foaming while drawing down a vacuum do cause the cactus juice to become an aerosol that can be sucked into the pump and accumulate.


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## TurnTex

You could be seeing some water boiling out of the Cactus Juice since the activator contains a small amount of water. I guess it could also be picking up water from the air in your Juice but I assure you, you are NOT seeing Cactus Juice boiling! Just not chemically possible unless the temperature of the resin is above 93° F. I too have seen the bubbles you mention so no need for video!


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## JR Custom Calls

TurnTex said:


> Boiling does not always require heat.


Well, actually, it does... Just perhaps not added heat. Anything above 0 kelvin has heat, and I would venture to say CJ wouldn't boil at full vacuum of at 0 k.

I'm just giving you a hard time lol... Having a father who taught chemistry, I became too familiar with some things.

Reactions: Funny 2


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## Sprung

Guess what I'm working on right now...


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## Sprung

While referencing Colin's write up, so I don't mess anything up.

Reactions: Like 1


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## Schroedc

Sprung said:


> While referencing Colin's write up, so I don't mess anything up.



Call me tomorrow if any questions

Reactions: Like 1


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## Sprung

Schroedc said:


> Call me tomorrow if any questions



Will do, if I have any. It's pulling vacuum just fine, but the drain valve was clogged with gunk so I pulled the front cover off to clean it out and figured I'd clean up anything else in there right now. While eating dinner I gave it some thought and am going to skip disassembling and cleaning the cartridge right now since it's working fine - no need to do it if it's not necessary and just focus on getting everything else cleaned up.

Reactions: Like 1


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## against.the.grain

If you temporarily cover the the exhaust( end of the handle) while the the pump is running , and the drain is open , the increased pressure may help to clear your clog. I do this with my thumb to speed up the oil change process. The pump needs to be pulling in some air to do so. Also make sure you have something in place to catch the spraying oil from the bottom of the drain.


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## Sprung

@Schroedc - thanks again for this write up! Previously I thought I was going to have to do this, but it really only needed the compartment cleaned out as it was running fine. But, after letting my pump site for a while (6+ months) unused, I flipped it on the other night and it was seized. Broke it down, gave it all a good soak in lacquer thinner, got it loose and spinning again, back together and pulling vacuum again.

Reactions: Like 2


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