Service Manual

13
BDP-10A/16A/21L
8. Inspect the vehicle control linkage to the di-
rectional control arm on the BDP. Also, in-
sure the control arm is securely fastened to
the trunnion arm.
9. Inspect the bypass on the BDP to insure it is
properly engaged for operation. If the bypass
is not fully engaged (rotated fully clockwise)
it will not function properly. For vehicle move-
ment, the bypass may be backed out (2) turns
maximum. This is only recommended for
movement of short distances at low speeds.
WARNING
Loosening the bypass will result in loss
of hydraulic braking capability.
SERVICE AND MAINTENANCE
PROCEDURES
NOTE: Damage to BDP’s may result from
external or internal contamination: Heat
from excess debris or lack of lubrication
and over-pressurization of the product.
Follow guidelines established in this
manual and the vehicle manufacturer’s
recommendations.
All the service procedures presented on the fol-
lowing pages can be performed while the BDP
is mounted on the vehicle. Any servicing beyond
those given must be performed after the unit has
been removed from the vehicle.
SECTION 4. SERVICE AND MAINTENANCE
NOTE: Any servicing dealer attempting
a warranty repair must have prior ap-
proval before conducting maintenance
of a Hydro-Gear product unless the ser-
vicing dealer is a current Authorized Hy-
dro-Gear Service Center.
EXTERNAL MAINTENANCE
Regular external maintenance of the BDP should
include the following:
1. Check the vehicle operator’s manual for
the recommended load ratings. Insure
the current application does not exceed
load rating.
2. Check fluid level in reservoir in accordance
with vehicle manufacturer’s recommenda-
tions.
NOTE: After oil has been drained and
maintenance has been performed, clean
oil should be poured directly into the
pump inlet and high pressure ports prior
to plumbing reconnection and start-up.
3. Inspect the vehicle drive belt, idler pulley(s),
and idler spring(s). Insure that belt slippage
is not causing low input rpm to the pump.
4. Inspect all external plumbing for possible
leaks or loose fittings. An air leak may be
difficult to detect on the “suction side” or inlet
line to the pump. See purging procedures
page 12.
5. Insure correct inlet filter(s) has been installed
in accordance with the vehicle manufacturer.
6. Insure the reservoir is free of contaminants
and is properly vented.
7. Inspect the BDP cooling fan (if applicable)
for broken or distorted blades and remove
any obstructions (grass clippings, leaves or
dirt). Inspect oil cooler (if applicable) for dam-
aged fins and debris.
FLUIDS
The fluids used in Hydro-Gear products have
been carefully selected, and only equivalent, or
better products should be substituted.
Typically, an engine oil with a minimum rating of
55 SUS (9.0 cSt) at 230
°
F (110° C) maximum
operating temperature and an API classification
of SJ/ CD is allowed. Refer to the vehicle manu-
facturer for recommended oil.