1998/04/06 Caterpillar

D250E (5TN),
D300E (7FN),
D350E (9LR),
D400E (2YR) Articulated Trucks

SUPPLEMENT: JUNE 1, 1998

Service Magazine SEPD0411, Article 20, Page 29, April 6, 1998; "Access Hole Dimensions To Measure Brake Lining Pad Thickness".

The location for the left hand hole in Illustraiton 2, is incorrect. This is for the D300E Articulated Truck. The following Illustration and dimensions should replace Illustration 2.

Illustration 2.
145-4944 Service Brakes for D300E Articulated Trucks.

(E) 24.13 mm (.950 in)

(F) 31.75 mm (1.250 in)

(G) 29.46 mm (1.160 in)

--------------- END SUPPLEMENT ---------------

The following dimensions and procedure to modify the brake caliper piston housings on articulated truck brakes allow monitoring brake lining pad wear for replacement requirements.

When removing the brake lining pads for replacement, drill two holes on the back side of the torque plates to the dimensions shown. Use a 7.80-8.18 mm (.307-.322 in) diameter drill.

Brake lining wear can be determined by inserting a measurement pin into the inspection holes, with the brakes applied, on new pads. Record these measurements at each wheel. Follow the Operations and Maintenance Manual recommendations for taking future wear measurements. When the pads have worn 15.24 mm (.600 in), they should be replaced.

Illustration 1.
145-4945 Service Brakes for D350E & D400E Articulated Trucks

(A) 22.86 mm (.900 in).

(B) 31.24 mm (1.230 in).

(C) 20.70 mm (.815 in).

Illustration 2.
145-4944 Service Brakes for D300E Articulated Trucks

(D) 31.12 mm (1.225 in).

(E) 17.78 mm (.700 in).

(F) 31.75 mm (1.250 in).

(G) 29.46 mm (1.160 in).

Illustration 3.
145-4943 Service Brakes for D250E Articulated Trucks

(H) 24.13 mm (.950 in).

(I) 15.88 mm (.625 in).

(J) 27.86 mm (1.097 in).

(K) 26.04 mm (1.025 in).