by Bob Beranek
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Part four in our series of ANSI/AGSC/AGRSS™ Standard 003-2015 changes is related to adhesives and their importance to the safety of the installation.

6.4 The vehicle owner/operator shall be notified prior to and after the installation process of the minimum drive-away time under the circumstances of the replacement.

The Safe-Drive-Away Time (SDAT) is one of the most important issues the mobile technician must communicate to the vehicle owner. If the vehicle is driven pre-maturely, there could be safety and performance problems with serious ramifications. We all know that the adhesives must be cured to the point of providing safety as defined by Federal Motor Vehicle Safety Standards 208 and 212. We must communicate to the customer that driving or moving the vehicle could cause the glass to shift, thus creating possible leaks and bonding problems as well.

This portion of the Standard assures that there is no mistake in communication when it comes to the customer’s use of the vehicle. Notifying the customer before the installation commences ensures that the customer is prepared to keep the vehicle stationary as prescribed by the cure rates and climatic conditions of the day. It also ensures the customer’s schedule will not be in conflict with the requirements. Reminding the customer after the installation reinforces the importance of SDAT and demonstrates its importance.

6.5 Adhesive must be applied so that the finished bead cross section profile and dimensions meet or exceed original equipment configuration or recommendation of adhesive system manufacturer.

Section 6.5 is the directive to replicate the original installation as closely as possible. However, all technicians know that obtaining the exact bead configuration and dimension can be difficult to do in the aftermarket. A robot can be programmed to extrude a specific amount of adhesive at the point of application. However, as the vehicle continues down the assembly line, the glass is leaned on and pressed in areas where other parts are assembled and the exact width and height can be changed. This directive is meant to ensure that the technician matches the original bead as closely as possible.

The change in this directive reflects the adhesive manufacturers’ role in determining the urethane’s proper performance features as designed by the automaker. Due to this involvement and the knowledge put forth in design, we, as aftermarket service providers, must respect their recommendations and follow their instructions to insure proper results.

I recently got a call from one my clients saying that they were doing a new 2014 Jeep Cherokee Trail Hawk which had a lane departure camera mounted on a bracket attached to the glass. As I had suggested in a previous post, they called their local Jeep dealer to schedule a calibration. The neighborhood service department knew nothing about calibration of the system. My client didn’t know what to do. So, thanks to some new information my friend Mitch Becker gave me, I suggested that they call a local Goodyear Auto Center and see if they could calibrate it for them. In the meantime, I decided to research this with my friends at Chrysler to find out if it needed to be calibrated or not.

Here is my research concerning the Chrysler lane departure system. I contacted my friends at Chrysler and they were kind enough to send me the information I was looking for. First of all, let me list the vehicles we are talking about:

—2014 Dodge Durango & Jeep Cherokee (DW2030-31); and

—2014 Grand Cherokee (DW2054-59).

As some of you know, Chrysler just added the lane departure feature in 2014 so I suspect that many dealers are as yet unaware of the calibration required. I suggest that you contact your local dealer and inform them about this feature, what it requires and where to look for the procedure. It so happens that the procedure is in their service manuals under:

—08-Electrical, 8E-Electrical Modules, MODULE, Forward Facing Camera/Installation

It wouldn’t be a bad idea to find out what they would charge for the calibration while you’re there as well.

Below are two pages from the Chrysler’s TECHAuthorityII.

TECHAuthorityII is an online service where visitors can pay to view all of the service manuals for Chrysler vehicles. There is a charge for the subscription, but in some cases, it may be well worth the cost.

BobMirror1

 

Bobsmirror2

The recent recall of airbags by some automakers has brought to the forefront the relationship between the airbag and windshield. This week I thought I would give you my opinion on this subject.

Some vehicles utilize the bonding and the strength of the windshield to help position the airbag after deployment. In other vehicles, the airbag deploys out the front of the dashboard so the windshield does not play as important a role. However, the majority of vehicles on the road today do rely on the windshield during airbag deployment in some way.

Fact: Safe Drive Away Time (SDAT) is defined as being met when the vehicle can pass Federal Motor Vehicle Safety Standards (FMVSS) 208 and 212. No. 208 is the passive restraint standard and 212 addresses windshield retention.

Question: How can urethane be strong enough to deliver SDAT when I know that it is not fully cured?

We know that urethane gains strength the longer it is exposed to humidity. The more humidity the urethane is exposed to, the faster it will cure. Modern urethanes have tensile strengths that exceed 700 psi, with some exceeding 1000 psi when fully cured. Tensile is the strength necessary to meet the FMVSS 208 & 212 requirements. In addition, there are other factors built into the chemistry of urethane adhesives that contribute to the initial strength of the adhesive.

The first generation of airbags exerted approximately 300 psi of force to the inside surface of the glass upon deployment. The new generation is significantly less than that. These facts put together give you the answer. Even with partial cure, the urethane is strong enough to withstand the pressures put upon it during airbag deployment. The only negative result will occur when you couple a poor application of materials with improper installation, which will cause the adhesives to perform improperly.

Adhesive companies and their chemists spend significant time and money testing their products. They know what sticks and what doesn’t. By following their instructions on safe drive away time to the letter, you will assure that your customers are safe.  

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