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Craftsman
Water Pump

Model # 3902521 Official Craftsman pump

Here are the diagrams and repair parts for Official Craftsman 3902521 pump, as well as links to manuals and error code tables, if available.

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Owner’s manual

Model diagram and schematic

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Showing 10 of 34 parts  |
Pump Body Gasket J20-18
#15

Pump only diagram

Pump body gasket

Part #J20-18

Replaced by #J20-18C

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Manufacturer substitution
This part replaces J20-18. Substitute parts can look different from the original.
This item is not returnable
$9.99 | 
9% OFF Phone Price : $10.99
Back Order
Pump Pressure Switch Tube U37-673P
#17

Pump only diagram

Pump pressure switch tube

Part #U37-673P

This item is not returnable
$19.98 | 
9% OFF Phone Price : $21.98
Back Order
Pump Shaft Seal 17351-0009
#2

Pump only diagram

Pump shaft seal

Part #17351-0009

This item is not returnable
$8.89 | 
10% OFF Phone Price : $9.89
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Pump Shaft Seal U109-6A
#7

Pump only diagram

Pump shaft seal

Part #U109-6A

Replaced by #U109-6B

?
Manufacturer substitution
This part replaces U109-6A. Substitute parts can look different from the original.
$106.69 | 
10% OFF Phone Price : $118.69
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Switch 2782
#28

Pump only diagram

Switch

Part #2782

Replaced by #TC2153-P2

?
Manufacturer substitution
This part replaces 2782. Substitute parts can look different from the original.
$59.89 | 
9% OFF Phone Price : $65.89
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Captive Air Tank Inlet Flange (replaces U131-422p) U31-446P
#2

Tank only diagram

Captive air tank inlet flange (replaces u131-422p)

Part #U31-446P

$43.09 | 
12% OFF Phone Price : $49.09
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Pump Hose Fitting, 90-degree U111-212T
#18

Pump only diagram

Pump hose fitting, 90-degree

Part #U111-212T

This item is not returnable
$27.69 | 
18% OFF Phone Price : $33.69
Back Order
Pump Diffuser J1-39P
#9

Pump only diagram

Pump diffuser

Part #J1-39P

$145.81 | 
8% OFF Phone Price : $157.81
In Stock
Pump Impeller J105-40PE
#8

Pump only diagram

Pump impeller

Part #J105-40PE

$139.59 | 
8% OFF Phone Price : $151.59
In Stock
Pump Check Valve (replaces N12-12p) N166-5P
#20

Pump only diagram

Pump check valve (replaces n12-12p)

Part #N166-5P

$123.89 | 
9% OFF Phone Price : $135.89
In Stock

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