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A heat shield is often used to protect a starter solenoid from high engine compartment temperatures. When installing a replacement starter, it may come with a heat shield or it may require transferring the heat shield from the failed starter.

If the original starter uses a heat shield, it's important to install the proper one on the replacement starter using the correct fasteners. Most heat shields clip or bolt to the starter. Certain styles of heat shields installed on GM vehicles use an M4x0.7x10.0 thread forming bolt. (Fig. 13, A) If this bolt is misplaced during service, it should be replaced with the same bolt, part number 10201205, available at any GM dealer.

Fig. 13

- Thanks to Mike DeSander

With TIS 2 Web, independent service centers have access to a variety of GM programming applications and software instantly available from a central website. No longer is it necessary to wait for a CD to arrive at the service center to have the latest programming updates.

TIS 2 Web is a new version of the GM Techline Information System (TIS) that includes a suite of diagnostic/programming applications, including Service Programming Systems (SPS) for GM vehicles (required to reprogram GM vehicle control modules), Tech 2 scan tool software download, and the Tech 2 View and Tech 2 Snap Shot diagnostic applications.

TIS 2 Web offers increased speed of updates, consistent software versions for all users, improved maintenance and support, and use with generic SAE J2534 devices.

TIS 2 Web Subscriptions

TIS 2 Web is available via an on-line subscription. Go to www.acdelcotechconnect.com and click on the TIS 2 Web logo under GM Service Information. Service centers can select from several annual subscription choices.

TIS 2 Web - All Access

(GM, Saturn and Saab) $1,395

This option for Tech 2 users includes:

Tech 2 Diagnostic Software

Tech 2 View

Tech 2 Snap Shot

Service Programming Software

TIS 2 Web - Service Programming

(GM, Saturn and Saab) $995

This option for use with J2534 devices includes:

Service Programming Software

TIS 2 Web - All Access

(Saab only) $750

This option for Tech 2 users includes:

Tech 2 Diagnostic Software

Tech 2 View

Tech 2 Snap Shot

Service Programming Software

TIS 2 Web - Tech 2 Diagnostics

(GM, Saturn, Saab) $750

This option for Tech 2 software only includes:

Tech 2 Diagnostic Soft ware

Visit www.acdelcotechconnect.com for complete details about the TIS 2 Web application, including subscription information as well as computer hardware and software recommendations.

- Thanks to John Putnam and Bob Stewart

The following technical tips provide repair information about specific conditions on a variety of vehicles. If you have a tough or unusual service repair, the TSS Technical Assistance Hot Line can help. Call 1-800-825-5886, prompt #2, to speak with a technical expert with the latest OEM information.

Clutch Bleeding Problems

Ford Ranger with non-self adjusting clutch sets

The non-self adjusting clutch sets may exhibit a problem of poor or no release of the clutch. The problem is caused by air trapped in the hydraulic system -- specifically the master cylinder.

In order to isolate and correct the condition, first eliminate the possibility of any worn or damaged components in the release system. With the clutch installed and the transmission in the vehicle, check to make sure there is no leakage from the master cylinder and around the fittings of the Concentric Slave Cylinder (CSC). Then, in order to determine if air is trapped in the master cylinder, disconnect the line going into the CSC and push down on the clutch pedal. The pedal should be stiff. Theoretically, if the master cylinder portion of the system is completely full of hydraulic fluid and has no trapped air, the pedal will not move at all (or very little - less than 1/2"). The reason this simple test works is due to the nature of the connector between the master and slave cylinder. When it is not connected to the slave cylinder the valve in the line stays closed and will not allow any hydraulic fluid to escape. 

During operation in the vehicle, the connections of the master cylinder are pointing down and the piston rests at the high end and is pushed down for the release stroke. This creates an air trap at the piston end away from the connector lines where fluid comes in and goes out. 

The illustration (Fig. 11) of the system as installed in the vehicle: 

A.) Location of trapped air

B.) Location of retaining clip

C.) Notice angle of master cylinder

D.) Bleeder valve

E.) Line connector

F.) Internal slave

Fig. 11

When the master cylinder is removed from the vehicle (Fig. 12) and manipulated so the lines are pointing up and the piston end points down (with the reservoir cap removed), the piston can be compressed into the slave cylinder and air bubbles will be seen escaping from the top of the reservoir if air is present. Once all the air is purged out of the master cylinder, it can be reinstalled on the vehicle. Before connecting the hard line to the CSC, push the pedal by hand to confirm it is solid.

Fig. 12

An alternative that can be tried before bench bleeding the master cylinder as described above is to raise the front of the vehicle to reduce the downward angle of the master cylinder and make it as level as possible and then bleed the system by repeating the following several times as needed:

Depress the clutch pedal fully

Loosen the bleeder screw on the CSC to allow air (and some fluid) to escape

Retighten bleeder screw

Release pedal

Power Steering Performance Concerns

2003-2006 Cadillac Escalade, Escalade ESV, Escalade EXT; 2003-2006 Chevrolet Avalanche, Suburban, Tahoe; 2003-2007 Chevrolet Silverado Classic; 2007-2008 Chevrolet Silverado, Suburban (2500 Series only); 2003-2006 GMC Yukon, Yukon Denali, Yukon XL; 2003-2007 GMC Sierra Classic; 2007-2008 GMC Sierra, Yukon XL (2500 Series only)

A lack of steering assist may occur when stopped or during parking maneuvers. This condition may go away or greatly improve once the vehicle begins to move or is above parking lot speeds. It may be aggravated by worn tires, low tire air pressure, low power steering pump pressures, and tires larger than stock size.

In all cases, it is recommended to use the proper tire size and that the maximum tire pressure is set according to the manufacturer's specification, especially for the front tires.

To repair this condition, perform the power steering system test found in the appropriate Service Information. Make any necessary repairs based on system diagnosis.

If diagnostics do not lead to any repair, this concern is a normal operating characteristic.

If the vehicle is equipped with a 670 gear box, it may be replaced with a 680 gear box. To determine if the vehicle is equipped with a 670 gear box, inspect the mounting bolts that attach the stub shaft housing. A 670 gear box will have only three mounting bolts. If replacing a 670 gear box with a 680 gear box, it will be necessary to replace the:

Power steering gear (GM part number 88965542)

Union fitting (GM part number 26025709)

Both inlet O-ring seals (GM part number 26001594)

The TSS Q&A provides answers to common questions received by the ACDelco Customer Support Center.

Q: Are TSS shops eligible for the GM New Vehicle Supplier Discount?

A: Yes. TSS service center owners and employees are eligible for the GM supplier discount on most new 2007, 2008 and 2009 GM vehicles at participating GM dealerships (eligibility may change at any time without notice and some models may have limited availability). So far this year, TSS shops have purchased more than 500 GM vehicles using the supplier discount.

Vehicles may be taken from dealer stock or ordered. In addition, the GM supplier discount can be combined with most other regional incentives for even greater savings. Savings using the supplier discount varies depending on model. (Fig. 10)

Fig. 10

Q: A GM New Vehicle Supplier Discount authorization number is needed to receive the discount. How do I get this?

A: Follow these steps to get a supplier discount personal authorization number:

Go to www.acdelcotechconnect.com

Click on the Total Service Support tab and then the GM Vehicle Supplier Discount link on the right side of the page. (You will have to log in by entering your 6-digit TSS code (it begins with a 6) and your zip code.)

On the GM Vehicle Supplier Discount page, click on the link at the bottom of the page to access the GM supplier discount website. It's important to always access the GM supplier discount website through acdelcotechconnect.com. This loads the website with the correct company code for TSS shops.

If you have used this website before, input your user name and password that you have used in the past. If you do not have a user name and password, click on New to Supplier Discount to register on the site.

Click "yes" when you are asked, "Are you a TSS/ACDelco account?" This question will only appear if you have logged in using a previous user name and password.

If you are asked if you would like to use this new account number because it has changed, always respond "yes." This is part of a recent change to improve the process.

Begin by selecting GM Supplier Discount on the left side of the page. Next, you are required to input your birth date, zip code, and other vehicle purchase information.

Once you have completed the process, print out your personal authorization number and bring it to your local participating GM dealer for your GM supplier discount.

Q: How many times in a year can I use the supplier discount?

A: TSS service center owners and employees are eligible to receive two supplier discount authorization numbers per year.

Q: How can I get more information about the GM New Vehicle Supplier Discount?

A: For additional information about the GM supplier discount or if you have questions about the authorization number process, call 1-800-960-3375. When calling, please state that your company name is TSS/ACDelco, not your individual service center name.

If you have any questions about the TSS program or any current ACDelco activities, contact the Customer Support Center at 1-800-825-5886, prompt 0.

ACDelco stands behind every product it sells -- all makes, all models.

When you, as a TSS shop, use ACDelco parts, the parts as well as the labor are warranted for 12 months or 12,000 miles, whichever comes first. It's the peace of mind that comes with the ACDelco Consumer Assurance Program.

After you have made repairs using ACDelco products, hand out a Consumer Assurance Program brochure to your customers. It provides all the details about the program works and how customer satisfaction is the top goal of your service center and ACDelco.

Updated posters (Fig. 9) and consumer brochures are available through the ACDelco E-Store.

Fig. 9

All TSS service centers are automatically enrolled in the Consumer Assurance Program. For complete details about the program, visit www.acdelcotechconnect.com. Here are some highlights:

If any installed ACDelco product fails within the 12-month/12,000-mile warranty period, the repair will be made at no additional cost for parts and labor.

If necessary, towing is covered.

If the failure occurs within 25 miles of the original repair facility, customers should return to that facility for ACDelco warranty coverage.

If the failure occurs more than 25 miles from the original repair facility, customers should call 1-800-ACDelco, prompt #3, for directions to the nearest TSS-participating service center for the repair.

Customers will need to provide their original sales receipt for authorization of the repairs.

- Thanks to John Putnam

Fuel contamination is the main cause of electric fuel pump failure. Dirty fuel, water, rust, scale and fuel tank sediment all work to clog the pickup strainer or inlet filter as well as cause internal pump damage. (Fig. 7) The result is premature pump failure. 

Fig. 7

When replacing a failed fuel pump, check the following to avoid future problems and a repeat failure:

Fuel contamination

Fuel tank degradation

Fuel line corrosion or damage

Blocked inlet strainer

Pump Diagnosis

Before condemning a fuel pump, the first step in fuel pump diagnosis is to perform a fuel pressure check. If the fuel pressure and volume are within specification, use a scan tool to check for diagnostic trouble codes.

If the fuel pressure check reveals improper fuel delivery, too-high or too-low pressure or insufficient flow, there could be a number of possible causes. These include a clogged inlet filter, damaged fuel pump, electrical faults, faulty fuel pressure regulator or fuel line restrictions.

In addition, inspect the terminal in the wiring harness connector and in the connector on the pump module. Any damage to the connectors may result in voltage drop across the module and may lead to a repeat failure.

Checking the Fuel

Once the fuel pump has been diagnosed as the cause of the customer concern, checking the fuel can identify any harmful additives, dirty fuel, or excessive water that could cause pump failure. (Fig. 8) If the inlet filter/strainer is clogging up, the pump's current draw may increase, which could quickly wipe out pump brushes with excess arcing and heat.

Fig. 8

When excessive fuel contamination is evident, remove and thoroughly clean the tank. Tank cleaning procedures vary among models, but general guidelines include: 

Disconnect the negative battery cable.

Relieve the fuel system pressure.

Drain the fuel tank and remove it from the vehicle.

Use oil-free compressed air to blow out fuel lines if needed.

Remove the fuel-sender assembly and inspect for damage.

Fill the fuel tank with hot water. Do this more than once, if necessary.

Pour the flushing water out of the tank through the fuel sender opening.

Ensure that all water is completely removed from the tank before reinstalling.

After cleaning the tank, the fuel and water mixture should be handled as hazardous waste material according to local, state and federal regulations.

Replace the Strainer

The fuel pump inlet strainer filters the fuel to help protect the fuel pump. It's essential that it be replaced and installed correctly when replacing the fuel pump.

On gerotor-type pumps, if the strainer is improperly installed, the gears can scuff and drag, causing noise and vibration. Without a properly functioning strainer, turbine-type pumps will quickly seize up. 

In addition to the strainer, the fuel system can be blocked by a crimp or dent in the fuel line. Any blockage can cause premature fuel pump failure. Also check fuel lines that appear sound externally but may have internal corrosion. Disconnect and inspect any suspect lines.

Fuel pumps do eventually wear out. But sometimes there are other factors that lead to fuel pump failure. It's important to perform a complete diagnosis of the fuel system in order to avoid a replacement pump failing as well. 

- Thanks to Dennis Kissack

"Why do I need to know Ohm's Law?" was probably a common question in high school physics class. And the teacher's common response was, "Because it's on the test." Fast forward to today and it seems like everything in the automotive service business is related in some significant way to physics, such as stoichiometric air fuel ratios, fuel pressure, hybrid powertrains, braking systems and mass airflow sensors.

For those of you who were (or are still) scared of physics, Bosch Diagnostics has teamed up with Midtronics, the industry leader in battery technology, to create a state-of the-art charging system analyzer that is robust and easy to use. Today's networked vehicles depend on consistent voltage, amperage and noise-free signals to operate. More than ever, proper charging system health is crucial to vehicle electronic control units (ECUs) functioning correctly. The BAT151 (Fig. 5) is a comprehensive tool that covers starting, charging, battery condition, voltage drop and a whole host of other electrical-system tests to quickly pinpoint the problem. The multi-language, easy-to-follow menus enable technicians to quickly isolate and repair electrical system problems using the automated testing sequences. Complex repairs will benefit from the individual testing selections that provide specific component-level testing with minimal hookup.

Fig. 5

At the heart of the BAT151 is Midtronics patented Dynamic Conductance technology, which combines direct temperature measurement and battery cell health checks. Advanced preventative maintenance algorithms help identify batteries that not only have failed, but also flag those that are nearing end-of-life. Optional amp clamp and test leads transform the BAT151 into a complete, portable system analyzer. Cable voltage drop tests are preconfigured for battery, starter and alternator, as well as the ability to create user-specific tests. Quick parasitic drain analysis and full multi-meter functions eliminate the need for a separate DVOM.

The BAT151 utilizes flash memory and is field updateable via USB connection. In addition, a user-supplied SD card can store test files, which can be viewed on a Windows PC in Internet Explorer® and transferred to a customer RO. An optional integrated printer provides an immediate customer printout, including easy-to interpret line and bar graphs. (Fig. 6)

Fig. 6

ACDelco TSS shops qualify for a special rebate on the BAT151. Visit www.acdelcotechconnect.com for details and pricing.

- Thanks to Bob Augustine