Thomas TG-550 Series, Manual

SERVICE KIT

 287845

Part No. 642704  06/05 

© 2005  Printed in U.S.A 

           All Rights Reserved

1918 

COMPRESSOR SERVICE KIT

TG-550 SERIES

Tools Required:  T-25 Torx

®

 screwdriver   

Phillips head screwdriver

Adjustable torque driver   

5/16” Socket for torque driver

3/4” Wrench 

1/4” Allen

®

hex bit for torque driver

STEP 1. 

Loosen and remove the hex fitting of the hose assembly 

at the control valve (3/4” hex).

STEP  2.

  Loosen  the  four  head  screws  from  each  head  and 

remove the head and valve plate assembly from the compressor 

housing. Discard the o-rings. Lay the heads on the same side 

they came off. They are to be replaced on the same side they 

were removed.

CAUTION: Improper assembly or use of damaged 

parts  may  lead  to  premature  failure.  To  avoid 

frequent  repairs  follow  the  recommended 

assembly procedures.
WARNING:  Drain  compressed  air  from  the 

tanks  before  disassembly. Allow  engine  and 

compressor to cool before disassembly. PREVENT 

ACCIDENTAL STARTING by removing spark plug 

wire when servicing engine or compressor. Also 

remove the spark plug for ease of rotating motor 

shaft.

NOTE: Before you begin, read these instructions thoroughly. 

Gather the necessary tools. This kit is for a unit with two 

heads and cylinders. Familiarize yourself with the parts in 

the kit. 

HEAD DISASSEMBLY

HEAD

SCREWS

HEAD

HEAD

O RING

VALVE

PLATE

ASSEMBLY

SLEEVE

O-RING

HOUSING

STEP 3. 

Remove the 4 front cover screws and remove the front 

cover. Remove 4 deflector cover screws and remove the deflector 

cover. Set both covers aside.

STEP 4.

 Remove the 5/16” screw holding fan, and set aside parts 

for assembly later.

Note: It may be necessary to secure motor shaft by inserting 

1/4” Allen

®

 wrench through housing access holes into eccentric 

set screw.

Deflector 

Cover

Front

Cover

Fan

Parts List for 1918 Service Kit

Part No. Description

Qty.

623075 O-Ring - Cylinder Sleeve

2

623082 O-Ring Gasket - Head

2

666931

Inboard Connecting Rod 

Ass’y (stamped “580” on the 

eccentric)

1

666932

Outboard Connecting Rod 

Ass’y (stamped “582” on the 

eccentric)

1

A Thomas Industries Company

For service, contact the dealer  from whom you 
purchased the compressor. To  order parts, visit 
our  website  www.thomasairpac.com  or  phone 
our customer service center at: 1-800-558-7721

Table of Contents

Page 6