Product Manual
Specications Information and Repair Parts Manual
DIAPHRAGM PUMPS
3370-PRV-OE 4 7/2020
2. The plunger bearing (Ref. No. P3) must be greased (any automotive
grease) after every 8 hours of use. Remove guard (Ref. No. A4) by
loosening two screws (Ref. No. A5). Grease tting on end of bearing; will
be visible after removing guard. Bearing may be cleaned and kept well
lubricated by pumping grease slowly into tting until new grease oozes out
between bearing and journal.
3. During freezing weather, be sure to drain the pump when it is not running.
Remove discharge hose and tip unit towards discharge side.
4. Keep pump clean. After use with liquids containing foreign materials, ush
with clean water.
REPLACEMENT OF FLAPPER VALVE
(Ref. No. W9)
1. Remove two bolts (Ref. No. W3) and remove suction priming plate (Ref.
No. W2). Replace apper (Ref. No. W9) on pin (Ref. No. W8) to locate on
suction plate.
2. Remove two bolts (Ref. No. W7) and remove discharge plate (Ref. No.
W6). Replace apper valve on pin (Ref. No. W8) to locate valve on pump
well (Ref. No. W1).
REPLACEMENT OF DIAPHRAGM
(Ref. No. P13)
1. Remove guard (Ref. No. A4) by loosening screws (Ref. No. A5).
2. Rotate pump until plunger arm (Ref. No. A2) is in the down position.
3. Remove pump well (Ref. No. A3) by removing screws (Ref. No. A8).
4. Remove diaphragm by removing four nuts (Ref. No. P12) from studs (Ref.
No. P11).
5. Replace diaphragm and reverse steps 1 through 4 for reassembly.
GEAR BOX OVERHAULING
A completely assembled gear box is available as a replacement part (Ref. No.
G28).
DISASSEMBLY
1. Remove diaphragm (Ref. No. P13) as described in “Replacement of
Diaphragm”.
2. Remove crank (Ref. No. P5) by loosening hex head screw (Ref. No. P7).
Use screwdriver in slot of crank to release clamp on output shaft (Ref.
No. G8).
3. Drain oil from gear box by removing drain plug (Ref. No. G4).
4. Remove driver (Ref. Nos. A28/A32) from adapter (Ref. No. G26) by
removing four bolts (Ref. No. A27) plus 4 additional bolts (Ref. No. A29)
from engine mount bracket (Ref. No. A16) for gas driver models. Slide
driver back from adapter until driver shaft disengages pinion (Ref. No.
G20).
5. Remove adapter by removing four bolts (Ref. No. G27).
6. Remove gear box from pump base (Ref. No. A7) by removing four bolts
(Ref. No. A6).
7. Remove pinion/bearing assembly (Ref. Nos. G15, G20, G24) by pulling
straight out. Use a slide hammer puller gripping in pinion groove
8. Remove twelve screws (Ref. No. G3) holding gear box halves (Ref. Nos.
G1 & G2) together.
9. Carefully separate gearbox halves; input (Ref. No. G2) and output (Ref.
No. G1).
10. Remove gasket (Ref. No. G22).
11. Remove output shaft/bearing assembly (Ref. Nos. G8, G9, G10, G11,
G12, G13) and idler pinion/bearing assembly (Ref. Nos. G13, G14, G17,
G18, G19).
12. Remove output shaft oil seal (Ref. No. G23) from output housing.
Diaphragm Pumps
13. Remove needle bearing (Re. No. G16) from inut housing.
14. Remove bearing (Ref. No. G15) from end of input pinion shaft (Ref. No.
G20).
15. Remove bearings (Ref. Nos. G13 & G14) from ends of idler pinion shaft
(Ref. No. G17).
16. Remove internal spur gear (Ref. No. G19) and key (Ref. No. G18) from
idler pinion shaft.
17. Remove retaining ring (Ref. No. G10) and bearings (Ref. Nos. G12 &
G13) from ends of output shaft (Ref. No. G8).
18. Remove output gear (Ref. No. G11) and key (Ref. No. G9) from output
shaft.
REASSEMBLY
1. Assemble input pinion/bearing assembly, idler pinion/bearing assembly
and output shaft/bearing assembly.
2. Install output shaft oil seal into gearbox output half. Lubricate lip seal.
Install needle bearing in gear box input half.
3. Slide output shaft through lip seal. Start output bearing in bore in gear
box output half. Position idler pinion bearing assembly in its bore in output
half. Simultaneously press both assemblies into output half.
4. Install gasket on output half.
5. Position gear box input half; align shaft bearings with bearing bores.
Press gear box halves together, align pins in output half with pin bore in
input half.
6. Secure halves together with twelve screws.
7. Slide input pinion/bearing assembly into bore in gear box input half.
Rotate pinion during installation to make sure gear teeth align with internal
spur gear teeth.
8. Reassemble gear box to pump base with four bolts.
9. Reassemble adapter to gear box with four bolts.
10. Align driver shaft key (Ref. No. A26) with keyway in pinion. Slide driver
into pinion, secure to adapter with four bolts (Ref. No. A27).
• (Gas engine only) Attach engine to engine mount with four additional
screw assemblies (Ref. No. A29).
11. Reassemble crank to output shaft as described under “Operation” section.
12. Replace diaphragm as described under “Replacement of Diaphragm”
section.
13. Fill gear box with oil as described under “Assembly” section.
14. Pump should be checked daily, weekly, monthly for proper operation.
NOTE: Only qualied service personnel should attempt to repair this unit.
Improper repair and/or assembly can cause pump damage, driver damage
and/or an electrical shock hazard depending on model.