COMMON PLUMBING PROBLEMS

PAN FILLS UP, TANK EMPTIES OUT

VACUUM LEAK BETWEEN PAN AND PUMP

• Poor hose to hose end connection
• "Scavenge in" fitting installed backwards
• Oil pan fitting installed backwards  (37 degree angle "in" instead of  "out")
• Pipe thread fitting used instead of J.I.C. type fitting
• Missing or defective O-ring on fitting
• Hole in "Scavenge in" hose
• Inefficient oil pan design - oil not reaching pick-up
• Defective pick-up - sucking air instead of oil
• Leak anywhere around an inline filter
• Inline filters are not recommended on "scavenge in" line
• Pan or pump fitting not sealing - bad 37 degree seal angle
• Sloppy hose cut - loose piece of liner causing "flapper valve" effect
• Defective hose end - cracked seal angle due to over-tightening or broken tubing

RESTRICTION IN "SCAVENGE IN" LINE

• Hose kinked
• Teflon hose used--heat softens Teflon lining, hoses suck closed
• Foreign object in hose
• Inline (paper) filter has disintegrated due to "surge" effect
• "Scavenge in" hose size too small - minimum required size: -10 (for 1.200 wide body)
• Cooler mounted on "scavenge out" hose too restrictive
• Screen type filter clogged
• Sloppy hose cut - loose piece of liner causing "flapper valve" effect at fitting
• Tank not vented properly

RESTRICTION IN "SCAVENGE OUT" LINE

• Hose kinked
• Foreign object in hose
• Inline (paper) filter has disintegrated due to "surge" effect of pumping oil and air, paper filters are not              recommended here.
• "Scavenge out" hose size too small - minimum required size: -10
• Cooler mounted on "scavenge out" hose too restrictive
• Screen type filter clogged
• Sloppy hose cut - loose piece of liner causing "flapper valve" effect at fitting
• Tank not vented properly

MASSIVE INTERNAL OIL LEAKAGE TO PAN

• No plug installed where stock oil pump fed system - oil pouring out rear main cap
• Internal oil galley plugs missing or leaking
• Inefficient lifter design - lifter bores leaking
• Lifter not in its bore

IMPROPERLY CONNECTED LINES

• "Scavenge in" and " scavenge out" lines cross connected

POOR PAN DESIGN

LOW OIL PRESSURE

RESTRICTION ON INLET SIDE

• Teflon hose used - heat softens Teflon lining, hoses suck closed
• Foreign object in oil tank

RESTRICTION ON OUTLET SIDE

• oil filter has collapsed internally

VACUUM LEAK ON INLET SIDE

• Defective hose end - seal angle cracked due to over-tightening
• Sloppy  hose cut - loose piece of lining causing "flapper valve" effect
• Missing or defective O-ring on fitting
• Pipe thread fittings used instead of J.I.C. type fittings
• Hole in "pressure in" hose
• Fitting not sealing - bad 37 degree seal angle
• Poor hose to hose end connection
• Air trapped in "pressure in" hose
• "Pressure in" fitting installed backwards

INADEQUATE SUPPLY OF OIL TO PUMP

• Kinked "pressure in" hose
• Oil level in tank excessively low (recommended oil level - 3/4 oil, 1/4 air space)
• Hole in pressure line - line leaking
• Sloppy  hose cut - loose piece of lining causing "flapper valve" effect
• Defective hose end - seal angle cracked due to over-tightening
• Filter on inlet side

PRESSURE PUMP RELIEF VALVE INOPERATIVE

• Poppet stuck in "open" position due to contamination in steel sleeve
• Silicone clogging relief valve vent - See Pump Repair Book
• Spring pressure weak

NO OIL PRESSURE

RELIEF VALVE INOPERATIVE

• No poppet in oil pump
• No spring  in oil pump
• Poppet stuck open due to foreign matter

IMPROPERLY CONNECT LINES

• "Pressure out" and "pressure in" lines cross connected
• "Pressure out" and "scavenge in" lines cross connected
• "Pressure out" and "scavenge out" lines cross connected
• "Pressure in" and "scavenge out" lines cross connected
• "Pressure in" and "scavenge  in" lines cross connected
• "Pressure in" or "pressure out" and vent hose lines cross connected

ERROR IN PUMP RE-ASSEMBLY

• Cross ported separator or mount plate installed between pressure and scavenge stages
• "Pressure out" fittings installed backwards

TOO MUCH OIL PRESSURE

IMPROPERLY CONNECT LINES

• Tank not vented properly
• "Pressure out" and "scavenge out" lines cross connected

RELIEF VALVE INOPERATIVE

• Poppet installed backwards
• Poppet stuck in "closed" position due to contamination in steel sleeve
• Silicone clogging relief valve vent - See Pump Repair Book
• Spring pressure too great

FRONT SEAL BLOWS OUT OF PUMP

SEAL IMPROPERLY INSTALLED

• Pounded into front body - seal deformed
• Seal and front body bore not primed and loctited

RESTRICTION IN "SCAVENGE OUT" LINE

• Hose kinked
• Foreign object in hose
• Inline (paper) filter has disintegrated due to surge effect (paper filter not recommended in "scavenge out" line)
• "Scavenge out" hose size too small - minimum required size: -10
• Restrictive cooler mounted on "scavenge out" hose
• Screen type filter clogged
• Sloppy hose cut - loose piece of liner causing "flapper valve" effect
• Tank not vented properly

BROKEN TIMING BELT

PUMP STOPS SUDDENLY

• No cross port between scavenge stages
• Large piece of engine debris locks pump up suddenly

BELT STRETCHED BEYOND ITS CAPACITY

• Small debris caught between belt and pulley
• Oil pump drive shaft bend
• Drive mandrel snout bent
• Initial belt tension too tight (belt deflection should be no more than 1/4" either way)

OIL BLOWS OUT OF VALVE COVER BREATHERS

EXCESSIVE CYLINDER BLOW-BY

• Too many miles on engine
• Rings defective (broken, chipped, etc...)
• Too much end gap

INADEQUATE ENGINE BREATHING

• Breather hose too small - minimum required size: -10
• Inefficient breather design - baffles allowing oil to pass or mesh not trapping oil

OIL LEAKS

AT PUMP DRIVE SHAFT

• Front seal defective
• Front seal not replaced on rebuild
• Front seat improperly installed
• Seal area on drive shaft damaged

BETWEEN PUMP STAGES

• No silicone used between stages
• Excessive silicone used
• Studs not torqued down in correct sequence
• Foreign matter trapped between mating surfaces of stages
• Dings, burrs, etc. on mating surfaces

AT FITTINGS

• Fitting not sealing - damaged 37 degree seal angle
• Missing or defective Orange on fitting
• Fitting installed backwards
• Poor hose to hose end connection
• Sloppy hose cut - loose piece of liner causing "flapper valve" effect
• Pipe thread fittings used instead of J.I.C. type fittings
• Orange installed on hose end side of fitting instead of port side
• No sealant used on port end of pipe thread fitting in oil pan
• Cracked or damaged pipe thread port due to over-tightening

IN HOSES

• Sloppy hose cut - loose piece of liner causing "flapper valve" effect at hose fitting
• Hole in pressure hose

Copyright (C) 1998  Weaver Brothers, LTD.

Page last modified February 07, 1998