773E Off-Highway Truck/Tractor and 775E Off-Highway Truck Suspension Cylinder: General Information

Visual Inspection

A visual inspection of each suspension cylinder is the first step in the analysis of a problem. Make sure that the machine is on level ground. Do the inspection on an empty machine while the engine is stopped.

Check each suspension cylinder for oil leaks around the seals and around the valves.

Check each suspension cylinder for nitrogen leakage. It is difficult to detect leaking nitrogen. A solution that consists of soap and of water can be used to detect leaks. Make sure that there is no leakage around the valve cores and around the valve bodies. Make sure that the valve caps are in place. Make sure that the valve caps are tightened to 2 to 3 N·m (18 to 27 lb in).

Check for leakage at the O-rings that are located under the manifold and under the pressure sensor. Check for leakage at the O-rings that are located under the protective plates that are on the head. These protective plates cover some of the head bolts in order to prevent removal of the head while there is pressure in the suspension cylinder.

Friction between the rod and the lower wear band may cause a dark stain to appear on the chrome of the suspension cylinder. This stain does not affect the wear life of the suspension cylinder. You can polish the chrome in order to remove this stain. Eventually, the wear band should become soaked by oil and by grease and the blackening should decrease.

Suspension Cylinder Oil Requirements

When you rebuild a suspension cylinder or when you assemble a suspension cylinder, use these oil requirements.

Table 1

Oil Requirements For Suspension Cylinders
Model Family	Front Suspension Cylinder	Rear Suspension Cylinder
769, 771	13.8 L (3.6 US gal)	11.2 L (3.0 US gal)
770, 772	13.8 L (3.6 US gal)	11.2 L (3.0 US gal)
773, 775	12.8 L (3.4 US gal)	12.0 L (3.2 US gal)
776, 777	34.5 L (9.1 US gal)	16.3 L (4.3 US gal)
784, 785	47.6 L (12.6 US gal)	25.9 L (6.8 US gal)
789	60.1 L (15.9 US gal)	35.6 L (9.4 US gal)
793	74.5 L (19.7 US gal)	35.6 L (9.4 US gal)
797 (1)	119 L (31.4 US gal)	48.5 L (12.8 US gal)
797 (2)	104 L (27.5 US gal)	48.5 L (12.8 US gal)
797B	104 L (27.5 US gal)	48.5 L (12.8 US gal)

( 1 )	5YW1-237
( 2 )	5YW238-Up

After the suspension cylinder contains the required amount of oil, install the suspension cylinder. After this has been done, the normal charging procedures can be performed.

Charging Tools

9U-5617 Oil Refill Pump (1) Shutoff valve for the regulator (2) 7S-5106 Chuck (3) Shutoff valve(4) Charging hoses

175-5507 Nitrogen Charging Group (5) 162-4147 Hose As (6) 8S-4600 Fitting (7) 8S-1506 Coupling (8) 162-4146 Regulator (9) 1S-8938 Chuck (10) 7S-5106 Chuck (11) 8T-0859 Pressure Gauge (12) 8S-4599 Coupling (13) 2S-5244 Fitting (14) 1S-8937 Needle Valve (15) 2D-7325 Pipe Tee(16) 1S-8941 Hose As

175-7410 Nitrogen Charging Fitting Gp (17) 8S-7169 Coupling (18) 1S-8941 Hose As (19) 7S-5106 Chuck (20) 175-6857 Hose As (21) 2D-7325 Pipe Tee (22) 1S-8937 Needle Valve (23) 5P-8998 Fitting(24) 3D-8884 Elbow

175-7410 Nitrogen Charging Fitting Gp is used with 175-5507 Nitrogen Charging Group in order to charge two suspension cylinders at the same time. 8T-0859Pressure Gauge is used to check the cylinder pressure before the charging procedure is performed.

Illustration of fabricated tool (gauge block) (A) Height dimension (B) Height dimension (C) 8 ± 1 mm (0.3 ± 0.04 inch) (D) 50 ± 2 mm (2.0 ± 0.08 inch) (E) 40 ± 2 mm (1.6 ± 0.08 inch)(F) 25 ± 1 mm (1.0 ± 0.04 inch)

Table 1

Front Suspension Cylinders FT1680 Gauge Block  Height Dimension (A) And Height Dimension (B)
Model	Height Dimension (A)	Height Dimension (B)
769, 771	-	170.0 mm (6.69 inch)
770, 772	-	170.0 mm (6.69 inch)
773, 775	-	170.0 mm (6.69 inch)
776, 777	216.0 mm (8.50 inch)	-

Table 2

Front Suspension Cylinders FT1975 Gauge Block  Height Dimension (A) And Height Dimension (B)
Model	Height Dimension (A)	Height Dimension (B)
776, 777	-	216.0 mm (8.50 inch)
784, 785	265.0 mm (10.43 inch)	-
789	265.0 mm (10.43 inch)	-
793	265.0 mm (10.43 inch)	-
797	265.0 mm (10.43 inch)	-

NOTICE
To protect the wiper seals on the front suspension cylinders from damage when the gauge blocks are inserted, make sure the gauge blocks include the chamfer.

If you need more information, You can visit:

http://www.cat.com

773E Off-Highway Truck/Tractor and 775E Off-Highway Truck Suspension Cylinder: General Information 2013-01-10T18:45:00-08:00 Rating: 4.5 Diposkan Oleh: Unknown