Edelbrock 66252, 66253 User Manual

Catalog #66252, #66253
©2006 Edelbrock Corporation

Page 1 of 3

Brochure #63-66252

Rev. 8/06 - DA/mc

TUBULAR EXHAUST SYSTEM

Applications: See Below

Catalog #66252, #66253

INSTALLATION INSTRUCTIONS

Please study these instructions carefully before installing your new

Tubular Exhaust System

(TES). If you have any
questions, please contact our Technical Hotline at : 1-800-416-8628 from 7 am - 5pm, Monday-Friday, Pacific
Standard Time or e-mail us at [e-mail]

.

APPLICATIONS: For 1998-1999 GM Tahoe,Yukon, Escalade 1500 Series, Suburban, and Pick-up, 5.7L-V8 Auto &
Standard Transmission, 2 & 4 WD with A.I.R. Dual catalytic.

TUBULAR EXHAUST SYSTEM: These components are designed to improve the exhaust efficiency of the GM C.P.I. (Central
Port Injection) V8 engine. A performance gain can be expected by the installation of the system. This system does

require welding for installation and retains all O.E.M. emissions equipment.

Suggested Tools Needed for Installation: This vehicle has metric fasteners.

❑ Mig welder (recommended) or gas welder—Professional welding is highly recommended
❑ 3/8” ratchet socket set with extensions and universal 13mm and 15mm swivel sockets
❑ Combination set of open-end wrenches
❑ Jackstands, screwdrivers, pliers, crescent wrench, etc.
❑ Hacksaw or Sawz-all
❑ Liquid penetrant, (GM #1052627) anti-seize compound (GM #5613695)

NOTE: Some models will require a special power steering pulley puller, K-D 2897 or equivalent

SPECIAL NOTICE: This Edelbrock Tubular Exhaust System has received an Executive Order number (E.O.#) from the

California Air Resources Board (C.A.R.B.) making it legal for street use in all 50 states. To assist you with emission
equipment certification, we have included a silver fan shroud decal to help testing personnel verify the this part is a legal
replacement on the vehicle for which it is cataloged. The adhesive-backed decal should be affixed next to the existing
emission and engine specifications decal. Do not cover any part of your original emission decal.

WARNING: The use of "Thermal Wrap" or any aftermarket coating process will void the warranty

on your Edelbrock
Tubular Exhaust Systems. Those products can cause excessive heat and moisture buildup resulting in corrosion and
failure of the system.

NOTE: High temperature spark plug wires and boots are recommended to withstand heat from T.E.S.

IMPORTANT NOTE:

Proper installation is the responsibility of the installer. Improper installation will void warranty and may

result in poor performance and engine or vehicle damage.

KIT CONTENTS

Catalog #66252 (Ceramic-Coated), #66253 (Ti-Tech Coated)

Qty. Description

❑ 1 Header left side #25-9458 (#66252)
❑ 1 Header right side #25-9457 (#66252)

❑ 1 Header left side #25-9136 (#66253)
❑ 1 Header right side #25-9137 (#66253)

❑ 1 Extension pipe left #25-9653
❑ 1 Extension pipe right #25-9654
❑ 1 4x4 Extension pipe (left) #25-9655

Qty. Description

❑ 12 Hex header bolts; 3/8” - 16 x 1”
❑ 2 Chevrolet V8 port gaskets
❑ 2 Donut gaskets; 2-1/4”
❑ 4 Hex capscrews; 3/8” x 2”
❑ 16 Lock washers; 3/8”
❑ 4 Flat washers; 3/8”

Catalog #66252, #66253
©2006 Edelbrock Corporation

Page 2 of 3

Brochure #63-66252

Rev. 8/06 - DA/mc

• DISASSEMBLY

1. Disconnect negative battery cable.

2. Raise vehicle and remove front two O2 sensors, being careful not to damage.
NOTE: Before cutting exhaust pipes from catalytic converter on both sides, determine the position of catalytic inlet
for re-installation. Use chalk line on bottom of floorboard to show position of catalytic and measure height from
floorboard.

3. For 2-wheel drive, not 4-wheel drive, cut both exhaust pipes 1/2" in front of weld on catalytic converters

(See Fig. 1).

4. Unbolt and remove exhaust pipes from exhaust manifolds.

5. For 4-wheel drive , unbolt unit from car without cutting pipes and set aside.

INSTALLATION INSTRUCTIONS

• RIGHT SIDE

1. Disconnect and remove air intake assembly.

2. Disconnect and remove spark plugs.

3. Disconnect A.I.R. injection assembly.

4. Unbolt dipstick tube.

5. Unbolt and remove manifold.

6. Install T.E.S. flange gasket and TES manifold form top. Install header bolts supplied and leave loose enough to
ensure proper alignment.
NOTE: Use flat washers at slotted ends and lock washers on all bolts.

7. Re-install spark plugs and wires.

8. Re-fasten dipstick tube.

9. Re-install air intake assembly.

• LEFT SIDE

1. Disconnect and remove spark plugs.

2. Disconnect A.I.R. injection assembly.

3. Unplug temperature sensor wire.

4. Unscrew E.G.R. hose from manifold.

5. Unbolt and remove manifold.
NOTE: Unscrew stock E.G.R. adapter form manifold and place it in T.E.S. header before installing.

6. Install T.E.S. flange gasket and T.E.S. manifold from top. Install header bolts supplied and leave loose enough to
ensure proper alignment. Tighten all bolts.

7. Re-attach E.G.R. hose.

8. Re-install spark plugs and wires.

9. Connect temperature sensor wire.

10. Connect A.I.R. injection assembly.

Cut O.E.M. pipe approximately 1/2”

in front of catalytic converter

Fig. 1

Catalog #66252, #66253
©2006 Edelbrock Corporation

Page 3 of 3

Brochure #63-66252

Rev. 8/06 - DA/mc

• ASSEMBLY OF EXTENSION PIPES ON GM PICK-UP

1. If your vehicle is 4-wheel drive, cut the right side exhaust pipe 1/2" in front of weld on catalytic converter,

(See Fig. 1)

. Cut left side exhaust pipe 2" in front of weld on a 15° angle cut,

(See Fig. 2)

. After cutting, place

unit back in vehicle.

Edelbrock Corporation, 2700 California St., Torrance, CA 90503

Tech Line: 1-800-416-8628

E-Mail: [e-mail]

Fig. 2

2. Install T.E.S. pipes to headers with donut gaskets, 3/8” x 2” bolts and lock washers supplied in kit. Be sure to locate
donut gasket with equal space all around for best seal

(See Fig. 3).

NOTE: Be sure to have the correct pipe on each side of the catalytic

assembly, or it will not set right. I.D. stamped on part: 25-9654-right,
25-9655 left (4 wheel drive), 25-9653 left (2wheel drive).

3. Use a 1-1/2” spacer under each catalytic converter to hold the
assembly at its proper height.

4. With everything in its place, weld pipes to cats. Remove spacers,
tighten all bolts.

5. Re-install O2 sensors.

• FINAL INSPECTION

1. Check all lines (hydraulic, vacuum, air conditioning and fuel) to
ensure there is adequate clearance to T.E.S. components.

2. Re-connect battery.

3. At this point it is a good idea to look everything over and make sure
that nothing was missed in assembly.

4. Start vehicle and bring up to normal operating temperature. Check
for possible leaks.

5. Turn engine off and let cool. Tighten all bolts again.

Make sure there
is equal spacing

all around

connection

Fig. 3

Side View of Extension Pipe Connection

Donut Gasket

Left Side on Four Wheel Drive

1 3/4"

2"

Catalytic Converter