5
IMPELLER
HOUSING
SMALL "O" RING (4)
LARGE "O" RING
"O" RING SEGMENT
HOUSING SCREWS (4)
SHAFT KEY
"CHIMNEY"
OF VOLUTE
FILLER PLUG
AND "O" RING
PUMP BODY
DRAIN PLUG
BODY SCREWS (10)
CHECK
VALVE
VOLUTE
IMPELLER
SCREW
SMALL "O" RING (1)
IMPELLER
SEAL
"O" RING
.015" SHIM AS
REQUIRED
SLINGER
1. Using a large screwdriver to remove the 1/4" screws, lock
washers and nuts, remove the pump body from the impeller
housing.
2. Remove the rubber check valve from the “chimney” of the
volute.
3. Remove the large self-tapping screw at the top of the volute and
the two smaller self-tapping screws at the sides of the volute.
4. Unscrew the 5/16-24 x 3/4 (fine thread) impeller screw and
remove it along with the small “0” ring. Slide the impeller off the
shaft and key.
5. One half of the shaft seal is in the impeller hub, the other half is
on the shaft inside the back plate. Remove both halves.
6. Remove the four steel screws (and small “0” rings) and pull the
impeller housing off the engine.
7. See that the key fits the shaft groove snugly. If it doesn’t,
replace the key with a wider one.
8. The clearance between the impeller blades and the volute must
be about .015" for good pumping. If the impeller blades and
volute are worn, there may be too much “front” clearance. You
can reduce the clearance by taking out one or more of the
shims between the impeller housing and the engine. After locking
the impeller back in place temporarily, check the impeller blade-
to-volute clearance with a feeler gauge. Continue (below) with
reassembly.
CAUTION:
When reassembling pump, (as in steps 10 through 15) after
adjustment of the clearance (as above) you must check that there is
no contact between the volute and impeller. Rotate shaft slowly by
hand and listen for scraping noises. If you hear no noises, put
priming liquid into the pump and start up the engine. If there is no
scraping noise, your assembly is probably O.K.
9. If you cannot get a clearance reasonably close to .015" between
the impeller and wear plate, install new parts as required.
10.During final assembly, be sure to change all of “0” ring seals
unless you are positive they are in good condition.
11.Put all of the parts back together in the reverse of the order
used in disassembly.
WARNING
Do not use any petroleum oil or grease in the assembly and do not
pump petroleum products with this pump.
HOW TO DISASSEMBLE AND REPAIR THE PUMP
PUMP MAY BE DISASSEMBLED
AND REASSEMBLED USING
ONLY A PIPE WRENCH AND
LARGE SCREWDRIVER
12. When assembling nipples, fittings, and elbows into the pump
body, wrap the male threads with Teflon® sealing tape. This
tape gives a more superior seal than pipe joint compound
without making the connections so tight as to damage the
threads. The proper tightness is
hand tight plus one full turn
with a pipe wrench. (No tighter than that, please.)
13. The four 5/16"-24 x 1-1/8" screws (with an “0” ring on each)
holding impeller housing to engine should be tightened securely
with a large screwdriver. When your rebuilding is completed, fill
the pump with liquid and test whether its full capacity has been
restored.
14. The screws holding the volute in place do not have to be
tightened any more than needed to secure the volute during
assembly. Overtightening may cut the “0” rings. The impeller
and the outside body screws should be made moderately tight
to insure against air leaks.
