Figure 4-3. Pressure Relief Valve Shims.

TM 9-2815-210-34-2-2

(d) Slowly close restrictor valve while watching pressure gage and

p r e s s u r e relief valve hole in pump. Check that oil starts to squirt out of pressure

r e l i e f valve hole when pressure gage reads between 140 and 225 pounds per square

inch.

( e ) If oil does not start

to squirt out of pressure relief valve hole when

p r e s s u r e gage reads between 140 and

225 psi, stop test. Take apart pressure relief

v a l v e . Refer to para 4-17a, frame 4.

Add or take out shims shown in figure 4-3 to

change relief valve opening pressure.

Do steps (c) and (d) again.

Pressure Relief Valve Shims.

(2) Flow test.

NOTE

P r e s s u r e relief adjustment must be done before

f l o w test. Refer to para 4-17e (1).

O i l pump has two halves. Front half of pump

b e h i n d drive shaft is called pressure pump.

R e a r half of pump is called scavenge pump.

( a ) If scavenge pump has not already been oiled, pour some engine

l u b r i c a t i n g oil into scavenge pump so scavenge pump impellers will not be damaged

d u r i n g test.

( b ) Hook oil pump to test bench as shown in figure 4-2.

( c ) Open pressure restrictor valve. Start drive unit, Run pump until

air is out of system and oil temperature holds steady at 200F to 210F for all engines

e x c e p t LDS-465-2 and 220F to 240F for engine LDS-465-2.

( d ) Work drive unit to speed up oil pump to 3,420 rpm. Slowly close

r e s t r i c t o r valve until pressure gage reads 110 psi.

( e ) For all engines except LDS-465-2, check that flow meter reads

2 2 gallons per minute (gpm) or more. If flow meter reads less than 22 gpm, get a

new oil pump.

( f ) For engine LDS-465-2, check that flow meter reads 26 gpm or more.

If flow meter reads less than 26 gpm, get a new oil pump.