Toro Multi Pro 1200 - Maintenance Procedures; Boom Bypass Valve and Pressure Dampener

Multi Pro 1200/1250 Hydraulic SystemPage 4 -- 31
CAUTION
The centering springs are under tension. Re-
move the retaining ring carefully.
10.Remove the spring retaining ring and centering
springs from the spool.
Control Valve Assembly (Fig. 25)
Check all mating surfaces. Replace any parts with
scratches or burrs that could cause leakage. Wash all
metalpartsincleansolvent.Blowthemdrywithpressur-
izedair.Donotwipepartsdrywithpapertowelsorcloth.
Lint in a hydraulic system will cause damage.
NOTE: Always use new seals and O--rings when as-
sembling the steering control valve.
IMPORTANT: During assembly, lubricate the new
seals withpetroleum jelly.Also, lubricate machined
surfaces and bearings with clean Dexron III ATF.
1. Install the quad seal:
A. Put one of the bearing races and sleeve into the
housing.
B. Together, the housing and bearing race create a
groove into which the quad seal will be installed.
C. Holdthebearingracetightlyagainsttheinputend
of the housing by pushing on the gerotor end of the
sleeve.
D. Fit the quad seal into its seat through the input
end of the housing. Be sure the seal is not twisted.
E. Remove the sleeve and bearing race.
2. Lubricate and install the dust s eal.
3. Install the centering springs in the spool. It is best to
install the two flat pieces first. N ext, install the curved
pieces, three at a time.
4. Fit the retaining r ing over the centering springs.
5. Apply a light coating of clean Dexron III ATF to the
spool and slide it into the sleeve. Be sure the centering
springs fit into the notches in the sleeve.
6. Install the pin.
7. Apply a light coating of petroleum jelly to the inner
edge of the dust and quad seals.
8. Put the thrust bearing and bearing r aces into the
housing.Thethrustbearinggoesbetweenthetwobear-
ing races (Fig. 26).
IMPORTANT: Do notdamagethe dustorquad seals
when installing the spool and sleeve assembly.
9. Apply a light coating of clean Dexron III ATF to the
spool and sleeve assembly. Carefully slide the assem-
bly into the housing.
10.Clampthehousinginavise.Useonlyenoughclamp-
ing force to hold the housing securely.
11.Lubricate and install a new O-ring (item 3) in the
groove in the housing.
12.Install the wear plate and align screw holes in the
wear plate with threaded holes in the housing.
NOTE: The holes in the wear plate are symmetrical.
13.Install the geroter drive, making sure the s lot in the
drive engages the pin.
14.Lubricate and install new O-ring in wear plate
groove.
15.Install the gerotor and align the screw holes.
16.Lubricate and install new O-ring in gerotor ring
groove.
17.Lubricate andinstallnew O-ring andsealring inger-
otor star groove.
18.Install the spacer.
19.Installtheendcapandseven(7)capscrews.Tighten
the cap screws, in a crossing pattern, from 140 to 160
in-lb (16 to 18 N--m).
20.Remove the steering control unit from the vise.
21.Install the check ball and plug with O--ring. Tighten
theplugto150 in-lb (17 N--m).
Thrust Bearing
and Race (2)
Quad Seal
Dust Seal
Figure 26
Hydraulic
System