Mityvac MVM8900 Pump Rebuild Kit - Manual

Page Section
- MV71 - 1A
Form 801519 JAN - 2009
MVM8900
Pump Rebuild Kit
For replacement of parts 1 through 15
1. Remove Dual Converter Knob Screw (1) using
small Phillips head screwdriver
2. Pull off the Dual Converter Knob (2)
3. Remove the Dual Converter Valve (3) by pushing
the stem through the Valve Housing
4. Remove the two Valve Housing Screws (4)
5. Remove the Valve Housing from the Pump Body
6. Remove the Front Seal Retainer assembly from
the cylinder of the Pump Body
7. With your thumb, push the Piston Assembly (8)
into the Pump Body cylinder. This will compress
the Piston Spring (9) and cause the Piston Rod
to extend from the back of the Pump Body as-
sembly.
8. With the Piston Rod extended, remove the Pis-
ton Rod Pin (10) and Pump Handle.
9. Remove the Piston Assembly (18) from the
Pump Body cylinder.
10. Remove the two Back Cap Screws (11).
11. Remove the Back Cap
12. Note the direction of the Piston Rod Seal (12).
The new seal must be installed in the same
direction (cup side inward) for the pump to func-
tion properly.
13. Remove the Piston Rod Seal (12).
14. Lightly lubricate* the new Piston Rod Seal (12)
and install into Pump Body.
15. Replace the Back Cap, and secure it with the
Back Cap Screws (11).
16. Clean and lightly lubricate* the inside of the
Pump Body cylinder.
17. Lightly lubricate and install the new Piston Seal
(7) onto the new Piston Assembly (8)
18. Assemble new Piston Spring (9) onto Piston
Assembly (8) and install into Pump Body cylin-
der.
19. With your thumb, push the Piston Assembly (8)
into the Pump Body cylinder. This will com-
press the Piston Spring (9) and cause the Pis-
ton Rod to extend from the back of the Pump
Body assembly.
20. Assemble the pump handle onto the Piston
Rod end and install the Piston Rod Pin (10).
21. Remove the old O-ring (5) and Umbrella Valve
(6) from the Front Seal Retainer.
22. Install the new O-ring (5) onto the Front Seal
Retainer.
PATENT PENDING
Installation Instructions
* Lubricate with Silicone Oil
17
©
© Indicates change