Author Topic: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup  (Read 14194 times)

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Offline pcmeiners

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #25 on: April 29, 2015, 08:28:52 am »
Nice write up Meggerman..

Have not played with the distributor bolt, when I get more time. I noticed the ultimate vacuum gets better as the units sit around, I assume the minute amount of rust or oil oxidation produces tiny particles which fill tiny leaks. As to compressor oil, Edwards oil at ripoff pricing only performs ever slightly better then cheap vacuum oil, not worth purchasing under most circumstances; Edwards advertisement hype makes their oil sound like a miracle curing for pump issues, snake oil anyone? As a positive note, it  does maintain viscosity better as it heats up.

Dogafly...

"Keep in mind that the pump that you're rebuilding might have been previously rebuilt by an idiot" Definitely do not trust a previous rebuild.
 As a note...  as I was rebuilding my pump, I was worried as to the accuracy of the Edwards pictorials, after do several pump they appear accurate.
 

Offline SeanB

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #26 on: April 30, 2015, 06:58:49 am »
I use refrigeration compressor oil, which is a plain SAE32 mineral oil. Do not use PAG or POE oils, as they degrade badly when exposed to moisture, and will corrode the pump very quickly.
 

Offline osp001

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #27 on: October 05, 2016, 05:30:07 pm »
Sorry to drag up an old topic, but-

I am refurbing an old M2E5, very very dirty, but much cleaner now. However, I was a dummy and neglected this piece of advice:

>The are two shaft seal to be replaced, remember the direction they are installed; the Edwards parts pictorial is not that clear.

Any idea which way part number 56 should face? Does the flatter side point towards the motor, or away?
 

Offline pcmeiners

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #28 on: October 06, 2016, 02:22:05 am »
The metal part (flatter part)  faces/is on the vane side, I put some loctite thread sealant in the area the seal rests in when installed. Goes flush, not below the body the seal sits in. Wipe any excess sealant off. I used a craftsman socket to push the seal in.
Good luck

Was thinking of this after I wrote it, now I am not sure which way the seal goes, best call Edwards. I checked over 20 pictorials, none of them show enough detail. Please post what you find out.
 
« Last Edit: October 07, 2016, 03:34:53 am by pcmeiners »
 

Offline osp001

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #29 on: October 29, 2016, 03:01:50 pm »
In case anyone stumbles across this in an attempt to rebuild an Edwards E2M5, I finished my rebuild and it's been humming for a week without catching on fire so maybe I did an OK job; I have no vacuum gauge so I don't know how good the vacuum is, but- it works.

I was able to figure out the position of the part 56 seal based on how badly I'd scraped up the original with the ring pliers, and it's the flatter side that faces *away* from the motor side- but that engineering manual that's on the web is just miserable. Too many parts not given the proper attention in the diagram.

The inner seal (between the first and second stages) was much more difficult. I didn't seat it straight, and lucked out when I took it to a pump repair company; when I got in there, I was feeling a little hopeless because they were working on huge agricultural pumps, with nary a vacuum pump to be seen. One of the more thoughtful engineers turned it over a couple of times, and asked "Is this out of a BOC Edwards?" There was no way to identify that pump from those parts, but he knew exactly what it was, and I told him he was bang on. Turns out he used to rebuild vacuum pumps at a previous job.

He took out the old seal, and we managed to re-use it. One little trick he used: He packed the back of the seal (where the metal spring fits) with Corning vacuum grease, using it to keep the spring from slipping out during installation- and I mean he packed it with vacuum grease, probably 1-2 cc's of grease. It got wiped clean-ish and re-installed, still cockeyed but better than I'd done it.

This has been my first attempt to rebuild a vacuum pump, and although I'd probably be more prepared to do another E2M5, I'm not sure I ever want to do another vacuum pump ever again. But if I did- this is how I did it the first time:

There were several layers of heavy polyethylene sheeting, probably 5-6 layers of 4 or 5 mil PE plastic. In the middle of all that, I put a clean cardboard box on which to put the pump so as not to tear the plastic. I also had a box of Rags-in-a-Box (Home Depot stuff), and two cans of non-chlorinated brake cleaner, and you might need three if it was *really* caked on there like this one was. I did as much as I could, and as it progressively got cleaner, I threw away the box and a layer of plastic- throwing everything into a box for disposal once the reassembly was complete, lest I disposed of a part wadded up in a paper towel. I don't think I lost any parts, but I do know I have a few extra O-rings that for the life of me I have no idea where they fit.

I'd also take pictures as I disassembled it. As it was, I used stacking plastic cups during disassembly; I find this is a convenient way to "peel an onion" like this, putting parts into a Dixie cup and then putting a clean one on top. Reversing the process usually makes it all go together so much easier. In this case, because so many of the bolts were tough to remove, and eventually (in frustration) I had to bang on it to get the first and second stages to come away, the disassembly wasn't quite so straightforward as I would have hoped. Plus, it was dirty- filthy- with heavily caked-on crud that even brake cleaner balked at. Soaking in a pail of lacquer thinner or paint thinner (I forget which) helped, coupled with a brass-bristled brush; Nylon bristles won't cut it. I would strongly recommend a box of gloves, discarded regularly, particularly if the pump had an unknown history. Too many things going into the pump oil because people don't trap their pumps properly... or at all.

A great learning experience, and I am better for it, but unless I were doing it for a living and had a workstation specifically adapted to this kind of work, I'm not sure as I'd want to do it again. The local vacuum pump place charges $1100 to rebuild an E2M5 (total rebuild), so financially it was worth it to me.
 

Offline pcmeiners

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #30 on: October 30, 2016, 02:56:20 am »
Thank for the addition osp001....

"manual that's on the web is just miserable. Too many parts not given the proper attention in the diagram."
Yes it is almost worthless, but that is the way the manufacturer wants it, forces you to call a repair shop or deal with them direct. As to the seal placement, you would think they would take extra care in a detailed picture. It is a matter of greed.

"Soaking in a pail of lacquer thinner or paint thinner (I forget which) helped"
Definitely the lacquer thinner works better, but it will mess up seals, so only use if a full seal kit is used. Chlorinated brake cleaner works better then non chlorinated.

" I would strongly recommend a box of gloves, discarded regularly, particularly if the pump had an unknown history."
Good point, who knows what was under vacuum.

Taking pictures during disassembly would be a good idea, there are many details which could be in doubt during reassembly, again as a result of Edward's CRAPPY parts pictorials. I only took pictures after the rebuild.

pictures of my dissembled pumps....

http://s852.photobucket.com/user/pcmeiners/library/Edwards%20RV3%20vacuum%20pump%20after%20final%20cleanup?sort=2&page=1

http://s852.photobucket.com/user/pcmeiners/library/Edwards%20E2M2%20Vacuum%20Pump%20overhaul?sort=3&page=1

 

Offline rachG

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #31 on: July 12, 2018, 08:36:20 pm »
Hey!
I am currently trying to rebuild an E2M2 pump. This walk through is a lifesaver! However I don't think my pump has ever been disassembled, it is full of some questionable deposits!
 
The kit that I received had two gas ballast valves, one for E2M2 and one for other pumps. Do you know which one is the one for the E2M2 pump? I was hoping to find one when I dismantled the pump, but there doesn't seem to be any of it left!

I have attached a picture of the two gas ballast valves in question.

Any help would be extremely welcome!
Cheers,
Rach
 

Offline rachG

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Re: Edwards E2M12 vacuum pump rebuild / overhaul / cleanup
« Reply #32 on: July 12, 2018, 11:03:29 pm »
Me again,
Had a look online for the ballast valve. Found a maintenance kit that was for one of the other pumps and it specified which shape was for the pump. So the valve on the left (4 pointed star?) is for pump E2M12, and this has a different gas ballast valve to the E2M2 pump (based on the exploded views + part number lists).
By process of elimination the one on the right with 2 semi circles cut out is for the E2M2 pump. (hopefully this is correct)

Hope this helps someone else!
Cheers,
Rachael
 


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