Relief Valve Inspection And Adjustment - Western HTS Mechanic's Manual

RELIEF VALVE INSPECTION AND ADJUSTMENT

Relief Valve Inspection
1. Remove the valve stem, ball,
spacer, and spring.
2. Look for broken or damaged
parts, contamination, or missing
or damaged O-rings.
CAUTION
Be careful to strike stem
squarely. You can bend stem if
you do not strike it squarely.
3. If parts are in good condition,
place ball on hard wood block,
hold stem seat on ball, and lightly
strike top of stem with a hammer.
This seats the ball and valve
stem.
4. Apply a light coat of anti-seize
or grease to stem threads.
Lubricate O-rings with hydraulic
fl uid. Reassemble components
into valve block.
Lit. No. 41467, Rev. 01
Adjustment
CAUTION
Do not adjust relief valve while
it is under pressure.
1. Adjust by tightening the relief
valve stem until it bottoms out
(until spring is fully compressed).
2. Back off valve stem (rotate
counterclockwise) the number of
turns indicated in the chart.
Spring
O-Rings
Hydraulic System
Relief Valve
C – Pump Relief*
A & B – Angle Cylinder Crossover Relief
D – Scrape Lock
* See Pump Pressure Test to measure actual pump relief pressure.
NOTE: Relief Valve Service: Apply one drop of low-strength threadlocker
to all relief valve stems. The spring for relief valve D is diff erent from
the other springs and should not be interchanged. Spring is made of a
lighter wire and is gold in color.
Spring Spacer
Ball
Valve Stem
No. of Turns Approximate Relief
Backed Off (CCW) Valve Pressure
From Fully Seated ± 100 (psi)
2-1/2 – 2-3/4 1650
1 – 1-1/4 4000
1/2 – 3/4 350
Adjustment of Scrape Lock
See page 74.
A
C
April 15, 2021
75
B
D