AIR CONDITIONER AR 4495721 - Caterpillar

Illustration 18
Erosion and pitting is isolated and does not connect any passages.
Use again
Illustration 19
Erosion damage around a fluid passage.
Do not use again--
unless the surface is repaired.
Illustration 20
Severe erosion damage has caused a path, indicated by the arrows, between a fluid passage and the outside surfaces.
Do not use again--
unless the surface is repaired.
Camshaft Bore
Inspect the camshaft bores for wear and impact damage whenever the camshaft has been removed. Remove any raised material with a file, and polish with a Scotch Brite pad if necessary. Refer to the camshaft bore specifications in this Guideline for maximum bore diameter. If any bore shows excessive debris damage, the spacer block must be replaced or repaired using replacement bearings.
Illustration 21
Inspect the camshaft bores for wear and impact damage.
Use again
Twinsert Installation Procedure
This procedure is used to repair M8 x 1.25 tapped holes in the spacer deck.
Carefully inspect for damaged holes. If required, remove any debris, old Heli-Coil insert, or pieces from the hole using needle nose pliers or a seal pick.
Measure the hole to determine the depth. Use a 1U-8168 Drill Bit to drill a 10 mm diameter hole to the original depth of either 12 .0 mm (.47 in) or 16 mm (.63 in).
Tap the hole to original depth using the special 135-7639 Tap.
Install a 135-7631 [12 mm (.47 in) long] or a 140-9745 [16 mm (.63 in) long] Outer Insert (larger diameter) using 135-7637 Installation Tool.
Break off the outer insert driving tang, using a 135-7638 Break-Off Tool.
Install a 135-7636 [12 mm (.47 in) long] or a 140-9740 [16 mm (.63 in) long] Inner Insert (smaller diameter) using an 8T-2790 Installation Tool. Position inner insert (2) so the end coil of the inner insert is flush with the end coil of outer insert (1), as shown in Illustration 22.
Break off the inner insert driving tang using a rod or punch slightly smaller than the minor thread diameter. The completed assembly will provide a Class 2B fit.
Illustration 22
Proper installation of inner (2) and outer (1) Twinserts with ends of inner (2) and outer (1) inserts correctly aligned.
Several utility boxes in the Cat system, such as 4C-3725 or 4C-4783 Plastic Divided Utility Box, are useful for organizing and storing installation tools and Twinsert packages.
Chart B.
Twinsert Installation Tooling
Part No. Description
1U-8168 Drill 10 mm
135-7639 Tap
135-7631 Outer Insert,12 mm
135-7636 Inner Insert, 12 mm
140-9745 Outer Insert, 16 mm
140-9740 Inner Insert, 16 mm
135-7638 Outer Tang Break-Off Tool
135-7637 Outer Insert Installation Tool
8T-2790 Inner Insert Installation ToolNote: Do not repair the holes using the 4C-8451 Heli-Coil Insert Package
(M8 x 1.25 x 12 mm long) which is offered in the Cat system. These inserts are a different length, and are intended for single-insert thread repair only; they must not be used in place of the
135-7636 Twinserts.