U 4.70-4.100
REPAIR & SERVICE
MANUAL
PAGE 1
Introduction
This manual covers repairs and service for the following Becker models:
U 4.70SA,and U 4.100SA series oil flooded vacuum pumps.
U 4.70F,and U 4.100F series oil flooded vacuum pumps.
This manual is intended to be used in conjunction with the current parts list for the appropriate model.
Reference numbers used in this manual are position numbers as shown on the parts list. The sealing
compounds and greases referred to in this manual are the sealants and greases recommended by the pump
manufacture. These are available through your Becker Pumps Distributor.
Disassembly
1.
Remove drain plug (#135) and drain oil from sump. (#61)
2.
Remove bolt and washer (#190 & 188) and remove protective hood. (#181)
3.
Remove 4 bolts (#194) holding motor flange (#251) to pump.
4.
Remove pump coupling (#18) and key. (#24)
5.
Remove inlet flange (#41) and check valve assembly.(#42+49)
6.
Roll unit on to side so that oil sump is on the bottom.
7.
Remove oil feed lines (# 141,#142,#158,and #150) from endshields, oil cooler and oil sump.
8.
Place oil cooler in safe place and allow to drain.
9.
Remove shaft end bolt (#32), cooling fan, (#30) and key. (#31) If puller is used to remove fan be
sure to protect threads in the end of the rotor by screwing a short bolt into the end of the rotor.
10.
Remove oil return line.(#143)
11.
Remove B-side endshield. (#16)
12.
Remove pump side motor flange/A-side endshield. (#15)
13.
Slide rotor (#3) out of cylinder housing. (#1)
14.
Roll unit back onto rubber feet.
15.
Remove bolts holding oil separator cover (#112) on and remove cover and separator elements.
(#83)
16.
Remove bolts holding sump cover (#64) on and remove cover.
17.
Remove coarse separator (#101) and screen. (#104)
18.
Remove nuts and washers (#71 and #70) holding sump (#61) to cylinder housing. (#1)
19.
Remove vanes, (#5) bearings, (#9) shims, (#8) and sealing washers (#7) from rotor.
20.
Remove shaft seals (#10) from endshields. Remove gaskets, O-rings, and sealing washers from
mating surfaces of all housings.
21.
Thoroughly clean all parts in suitable solvent, flush all oil lines and cooler.
22.
Inspect all components for wear or damage. Thoroughly inspect rotor, endshields, and cylinder for
wear or damage. (Scoring, chatter marks, unusual wear, and damage to sealing surfaces.)
Reassembly
1.
Install new shaft seals (#10) in endshields. Coat outside diameter of shaft seal with a thin coat of
Curil K2 and press seals squarely into endshields with suitable tool.
2.
Apply Ambligon TA 15/2 grease between the lips of the shaft seal. Fill space approximately 1/3
full.
3.
Install 1 bearing shield (#7) and 1 shim (#8) on each end of the rotor shaft and press bearing (#9)
onto shaft with appropriate tools. If bearings are shielded on one side, the shield faces the main
body of the rotor. (You can also shrink the bearings on to the shaft by heating the inner races of the
bearing to 200 degrees and quickly sliding the bearing onto the shaft.)
