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Let’s take it apart

E2M1.5 Rebuild

February29

E2M1.5 rebuildI ordered a rebuild kit a few days ago from Capitol Vacuum and forthwith it appeared on my doorstep. I also ordered a gallon of grade 19 vacuum pump oil – it is a must-have.

E2M1.5 Rebuild - 01

I took a slightly different route this time disassembling the pump. I took the baffles off of the top first. If you do this, be careful – there are all sorts of springs that are bound up in this mess.

E2M1.5 Rebuild - 02

To get at the shaft seal for the oil pump, one has to get the interior face of the oil pump out. I used the curled end of a paint key to reach in between the gap between the face plate and shaft seal. After giving it a few taps with a mallet it popped right out.

E2M1.5 Rebuild - 03

The kit includes an O-ring that seals between the oil pump and second vacuum stage. It also includes a new shaft seal. While this pump was apparently rebuilt at some time in the past, I am guessing that the shaft seal in the oil pump was never replaced. To get it out, I laid the part face-down on the workbench (flipped from the way it is in the photo) and used the paint key again.  It took significantly more persuasion to get the shaft seal out, but it did come out.

E2M1.5 Rebuild - 04

You’ll notice in the picture that there is a pin in the body of the oil pump. This fits loosely into a hole in the plate I removed earlier. It serves to align the plate and keep it from turning.

After I got the new shaft seal in, I moved to the rotors. I took them apart again using the screw method I mentioned in the disassembly post. I wanted to do this not because there is anything in there to rebuild but because I wanted to pre-oil the shaft since there are no bearings – it is metal to metal. I went on to replace every O-ring I could find and saved the motor drive shaft seals for last.

There is a plate on the motor end of the pump similar to the one at the oil pump end. I used the same paint key method to tap off the plate and get the drive seals out. The plate was slightly tighter since it has an O-ring on it. To reinstall the outer seal, I took a block of wood and gently tapped the seal into place. It slipped in a little too far, so I laid the whole frame on the block and used a 7/8″ socket (hey – it fit the hole perfectly) to drive the seal against the wood block from the inside. The inner seal sits down in the hole and to install it I used the block to drive the seal flush and then the socket to start it into the hole. To get it into its final position, I took the O-ring off of the plate and tapped it into place, driving the shaft seal into just the right depth. Once again I removed the plate, installed the O-ring, put a little oil on it and reinstalled it. Like the plate at the oil pump end, this plate aligns with a pin.

E2M1.5 Rebuild - 05

So here’s the pump with the new shaft seals installed along with the felt to absorb any oil that escapes. The hole that the shaft seals fit into had a few gouged places in it and I’m hoping that doesn’t cause me trouble.

As I reassembled the pump, I oiled every shaft or face that moves against anything else. At this point, it would sure be nice to have the front bearing for the motor. In order to get the bearing off of the motor, I had to knock off the part of the drive shaft which extends into the pump. To get it in the right position when I reassemble the motor, the shaft needs to be poking through the seals into the pump chamber. I believe when I got the pump that the drive shaft was pressed too far onto the motor shaft because the shredded plastic drive member looked like this:

E2M1.5 Rebuild - 06

It appears that there was about 1/16″ too much space between the end of the drive shaft and the rotor meaning that the motive force generated by the motor was applied at the tips of the drive member rather than toward the roots where instinct tells me the plastic would better handle the torque. So I plan to push the drive shaft back on the motor in situ until the new drive member is flush with the face.

E2M1.5 Rebuild - 07

Now that I have a clean dry pump, I’d like to keep it that way. Using the flange-type goodies I got earlier along with the original clamp from the pump, a 1/4″NPT to 1/4″ SAE flare adaptor and an HVAC service port cap, I assembled them onto the inlet port. No teflon tape or thread sealant – just screwed together for now.

E2M1.5 Rebuild - 08

For the outlet port, I cut a short length of hose to fit the nipple and jammed a wire nut in the end. That left the drive shaft hole. To stuff it temporarily, I simply poked the drive shaft into the hole.

Now if only I had a new bearing for the motor, I could go on with assembly. But I don’t. So I’ll have to wait a few days until I get one.

On to Part 3: Motor Rebuild

posted under Equipment, RepairIt
2 Comments to

“E2M1.5 Rebuild”

  1. On February 20th, 2013 at 7:41 pm Roger Mattila Says:

    Thank You for your work!

    I have a problem with my Pump Today and I found your information.

    With it I took my pump apart and discovered that I also sheered off that Plastic coupler — but mine is completely gone.

    Now trying to get into where that coupler is….and I can figure that out.

    Any other advice would be great.

  2. On June 20th, 2017 at 8:39 am ABBACI Mohamed Says:

    Hi,
    Thanks for all this information, and i need more information on shredded plastic drive in ordrer to replace him.
    best regards

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