General Information

Hydraulic Hoses

Hydraulic hoses are subject to extreme conditions such as pressure differentials during operation and exposure to weather, sun, chemicals, very warm storage condi- tions, or mishandling during operation or maintenance. These conditions can cause damage or premature dete- rioration. Some hoses are more susceptible to these conditions than others. Inspect the hoses frequently for signs of deterioration or damage.

When replacing a hydraulic hose, be sure that the hose is straight (not twisted) before tightening the fittings. This can be done by observing the imprint on the hose. Use two wrenches; hold the hose straight with one and tighten the hose swivel nut onto the fitting with the other.

WARNING

Before disconnecting or performing any work on hydraulic system, relieve all pressure in system. Stop engine; lower or support box and/or other attachment(s).

Keep body and hands away from pin hole leaks or nozzles that eject hydraulic fluid under high pressure. Use paper or cardboard, not hands, to search for leaks. Hydraulic fluid escaping under pressure can have sufficient force to penetrate the skin and cause serious injury. If fluid is injected into the skin, it must be surgi- cally removed within a few hours by a doctor familiar with this type of injury. Gangrene may result from such an injury.

Hydraulic Fitting Installation

O–Ring Face Seal

1.

Make sure both threads and sealing surfaces are

free of burrs, nicks, scratches, or any foreign material.

2.

Make sure the O–ring is installed and properly

Nut

Sleeve

Body

Hydraulic

Systems

 

 

seated in the groove. It is recommended that the O–ring

be replaced any time the connection is opened.

3.

Lubricate the O–ring with a light coating of oil.

4.

Put the tube and nut squarely into position on the

face seal end of the fitting and tighten the nut until finger

tight.

5.

Mark the nut and fitting body. Hold the body with a

wrench. Use another wrench to tighten the nut to the cor-

rect flats from finger tight (F.F.F.T.). The markings on the

nut and fitting body will verify that the connection has

been tightened.

Size

F.F.F.T.

4

(1/4 in. nominal hose or tubing)

0.75 + 0.25

6

(3/8 in.)

0.75 + 0.25

8

(1/2 in.)

0.75 + 0.25

10

(5/8 in.)

1.00 + 0.25

12

(3/4 in.)

0.75 + 0.25

16

(1 in.)

0.75 + 0.25

Seal

Figure 1

Final

Position

 

Mark Nut

 

 

and Body

 

 

Extend Line

Initial

 

Position

 

 

Finger Tight

After Proper Tightening

Figure 2

Sand Pro 2020/3020/5020

Page 4 – 3

Hydraulic System (Rev. A)

Page 53
Image 53
Toro 3020, 5020, 2020 service manual Hydraulic Hoses, Hydraulic Fitting Installation, Ring Face Seal