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Steve
Steve, Motorcycle Mechanic
Category: Motorcycle
Satisfied Customers: 6845
Experience:  30+ yrs. experience, MMI, HD technician, HD early, engine rebuild/performance, bike builder, kit bike program manager, CCI 2001-2004
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The Harley oil pump pressure relief valve, how does this work..EVO

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the Harley oil pump pressure relief valve, how does this work? I am trying to remove one from a 1990 EVO oil pump. It seems stuck. I see there is Sifton removal tool, is this the only way to remove the plunger?

Hi Kolors,

I have removed stubborn ones on the bike by inserting the tip of external retaining ring pliers into the top of the plunger and applying gentle outward pressure while easing the plunger out.

if it's just hydraulically locked by suction from the oil, sometimes they will come out by inserting a magnetic retirval tool into the plunger and easing it out.

if those two methods fail, you will have to remove the oil pump body from the engine and extract the plunget by use of compressed air or other mechanical means.

Steve

Customer: replied 7 years ago.
Thanks, XXXXX XXXXX have alreadt tried all that. The pump is off the bike and I am getting ready to re assemble the motor. I have even tried a tap and tried to pull it out...stilll nothing

Kolors,

perhaps you could tell me everything you have tried so I may be able to suggest other solutions without wasting so much of your time???????

if the pump is dry, the piston may be stuck as a result of galvanic corrosion. if this is the case, you will not remove the piston without scoring the bore and the oil pump body will have to be replaced.

steve



Edited by steve on 1/1/2010 at 12:11 AM EST
Customer: replied 7 years ago.
yes it is. it has been apart for months. I bought the motor in pieces. The pump is tonr down except for the plunger.

if the pump is dry, the piston may be stuck as a result of galvanic corrosion. if this is the case, you will not remove the piston without scoring the bore and the oil pump body will have to be replaced.

Steve

Customer: replied 7 years ago.
If the plunger is stuck shut, would this cause the motor to have exsessive oil pressure and cause the motor to leak oil? I am pretty sure the pump is junk at this point.

Kolors,

a stuck shut relief valve results in excessive oil to the top end and no oil through the pinion shaft to the flywheels. in this case, all lubrication to the crankpin would be by fly off from the flywheels. there would be no lubrication to the crankpin on start up.

typically, leakage is not an issue.

the oil pump should be replaced.

Steve

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