Webasto U4814 Operating and installation instructions

Service Information
Rev. 04/2004 • 907634
Webasto Product North America, Inc. •North American Headquarters • 15083 North Road • Fenton, Michigan 48430
For Technical Assistance Call: [phone] • In Canada Call: [phone]
Visit us on the Web at: www.webasto.us (North America) www.webasto.com (Global)
Seal Kit Assembly Instructions for Coolant Pumps:
U4814, U4816, U4817 and U4851*
04-15-2004
Revised Seal Kits (P/N 50906084A & P/N 5000153A) for Circulation Pumps with Axial Face Seals.
Seal Replacement Kit Contents:
1 Pump impeller
1 Pump housing base with integrated seal.
1*Pump cover
1 Sliding seal ring with date of manufacturing (in protective
container)
1 Nut
1 O-ring seal
4*Screws
4*Spring washers
1 Washer
1 Splash guard
1 Bottle of lubricating oil
1 Replacement part label
1 Service Information Bulletin (P/N 907634)
*not included in seal kit P/N 50906084A
General Information
A new sliding seal ring is included in the replacement kit
50906084A for maintenance work on circulation pumps U4814,
U4816, U4817 and U4851*. Care should be taken
when installing the sliding seal ring. When replacing parts,
the entire seal set must be replaced, not just the sliding unit.
ATTENTION!
Before using a replacement part, check date of manufacture
on the sliding seal protective container. Maximum shelf life is
4 years after date of manufacture.
Disassembly (See Figure 2)
1. Remove screws (item 1).
2. Remove pump cover (item 2), check for damage and
discard if necessary (replacement part P/N 5097664A).
3. While pressing against pump impeller (item 4) remove nut
(item 3) from motor shaft and discard.
4. Pull off pump impeller (item 4), washer (item 5) from
motor shaft and discard.
5. Remove screws (item 8) together with spring washers
(item 9) from pump base (item 10) and discard.
6. Pull off pump base (item 10) with axial seal (item 6), base
axial seal (item 13) and the O-ring seal (item 7) from motor
shaft and discard.
7. Pull off washer (item 11) and splash guard (item 12) from
the motor shaft and discard.
8. Check motor for smooth running. If damaged or an
unbalanced state or noise is noticed, replace motor.
Replacement
Part Label
Figure 1
Figure 2: Disassembly
Motor Shaft
Legend for Figure 2
1 Screw (4)
2 Pump cover
3 Nut
4 Pump impeller
5 Washer
6 Axial face seal
7 O-ring seal
8 Screw (4)
9 Spring washer (4)
10 Pump base
11 Washer
12 Splash guard
13 Base axial seal
NOTE: U 4851 Pump has been superseded to U 4855 Pump.

Service Information
Rev. 08/2021 • 907634
Webasto Product North America, Inc. •North American Headquarters • 15083 North Road • Fenton, Michigan 48430
For Technical Assistance Call: [phone] • In Canada Call: [phone]
Visit us on the Web at: www.webasto.us (North America) www.webasto.com (Global)
Seal Kit Assembly Instructions for Coolant Pumps:
U4814, U4816, U4817 and U4851*
Page 2 of 2
Assembly (See Figure 3)
ATTENTION!
Do not damage the motor shaft’s surface during the following
procedures. Prevent liquid solvents from penetrating into the
motor bearing.
1. Remove dirt and deposits from the motor shaft.
NOTE:
On circulation pump U4814, check screws on the bearing end
plate for a tight fit and tighten to 2 Nm. (17.7 lb-in.)
2. Slide the splash guard (item 11) and the washer (item 10)
to the limit stop on the motor shaft.
3. Cut the top of the lubricating oil bottle open. Cover the
motor shaft completely with a film of lubricating oil,
while the shaft is in a horizontal position, as shown in
figure 3.
NOTE:
Cover the motor shaft completely with lubricating oil in order
to ensure a correct assembly (self-adjustment) of the sliding
unit and to prevent leakage.
ATTENTION!
The lubricating film on the sealing surface of the base axial
seal should not be damaged or removed.
Avoid impurities on the sealing surface!
4. Remove pump base (item 9) with integrated axial seal
(item 12) from its individual packaging.
5. Slip pump base (item 9) onto the motor shaft towards
splash guard (item 11) and align it with the mounting
holes on the motor flange.
6. Attach the pump base with screws (item 7) and spring
washers (item 8) and tighten screws to 4 Nm. (35.4 lb-in.).
7. Remove sliding seal unit (item 5) from protective cover
(item 13).
8. Align sliding unit (item 5) with motor shaft (flat regions)
and slide it onto the shaft until it touches the limit stop.
9. Slide pump impeller (item 4) onto the motor shaft (sliding
seal is self adjusting).
10. Install nut (item 3), adjust pump impeller (item 4) and
tighten the nut to 1.5 Nm (13.2 lb-in.).
11. Install O-ring seal (item 6) on pump base (item 9) twist-free
over the edge.
12. Place pump cover (item 2) over pump base (item 9), fasten
with screws (item 1) and tighten screws to 2 Nm.
13. Punch out the dates of initial operation (month/year) on
the “Webasto-replacement part” label and attach the label
to the motor body, as shown in figure 1 on previous page.
14. Install the circulation pump in the vehicle.
15. Check for smooth operation without leakage.
ATTENTION!
If the replacement part label is not attached or the dates on
the label are not punched out, the warranty is void. Do not
paste anything over old labels, should parts be replaced several
times during the motor’s service life.
Legend for Figure 3
1 Screw (4)
2 Pump cover
3 Nut
4 Pump impeller
5 Sliding unit
6 O-ring seal
7 Screw (4)
8 Spring washer (4)
9 Pump base
10 Washer
11 Splash guard
12 Integrated axial seal
13 Protective container
for sliding seal with
manufacturing date
14 Bottle of lubricating oil
Figure 3: Assembly
Motor Shaft
NOTE: U 4851 Pump has been superseded to U 4855 Pump.