The 1990-1993 Chrysler Imperial

by Rich Hutchinson

The Chrysler Imperial

The Imperial moniker has a long and storied place in Chrysler history. An Imperial was the top of the line; the very best. There hadn't been an Imperial produced since 1983.

Ironically, the 1990 Imperial was introduced during diffcult financial times for Chrysler, just as the 1981 model was. The 1990 Imperial was a four door sedan, based off the K platform that had just begun back in 1981. Unlike the 1981-1983 Imperial, this one wasn't far removed from its brethren; the 1981-1983 Imperial had been based on the more fitting Cordoba chassis, but was clearly differentiated from the “personal luxury” car.

 

 

 

 

 

 

 

 

 

As much as Chrysler tried, it was just too obvious that the EEK Imperial was near a twin to the Fifth Avenue. Aside from length (203" compared to 198.6" - due to the front clip), specifications for the Imperial are nearly the same as the Fifth Avenue. In 1991, it even shared an engine with the Fifth Avenue, the 3.3 liter Chrysler V6 (though a V8 was available, it would have been difficult to fit into the vehicle, and did not generate much more power). In 1991 the 3.8 liter V6 was launched as standard equipment on Imperial, optional on Fifth Avenue. The differences between the cars were in the details.

 

 

 

The Imperial was unaffected by the facelift afforded the Fifth Avenue and New Yorker in 1992.

Detail Differences

The Interior

A slightly different dashboard top, unique seat coverings, and door panels sum up the differences that set the Imperial apart. Items that were options on the Fifth Avenue were standard on the Imperial, and by choosing the Imperial buyers achieved the appearance difference that set it apart from other New Yorkers more than the Fifth did.

The Exterior

An extended Landau roof, lengthened and taller front clip, and unique taillight treatment were the prime distinguishing marks of the Imperials exterior.

The Warranty

To emphasize the higher level of luxury of the Imperial and Fifth Avenue, those models were covered under Chrysler's Crystal Key Owners Program, which provided 5/50 bumper to bumper, 7/70 engine and powertrain, and 7/100 outer body rust through protection.

The protection afforded lesser models was a 1/12 bumper to bumper and 7/70 engine/powertrain along with the 7/100 corrosion coverage.

Note that this coverage is only mentioned in the 1990 and 1991 brochures, the 1992 brochure just says 'see your dealer for details' without mentioning Crystal Key at all. The 1993 brochure only offers the choice of 3/36 bumper to bumper OR 1/12 bumper to bumper along with 7/70 engine powertrain. 7/100 corrosion came on all cars. This seemed to emphasize the phasing out of the luxury K based sedans.

Antilock brake retrofit

by Brad Hogg. Used by permission.

THIS PROJECT DEALS WITH THE BRAKING SYSTEM ON A 1990 IMPERIAL. THE MODIFICATIONS MADE DURING THIS PROJECT ARE PURELY EXPERIMENTAL AND HAVE NOT BEEN TESTED OR SANCTIONED BY ANYONE, INCLUDING THE AUTHOR AND ALLPAR. THE AUTHOR AND THOSE ASSOCIATED WITH THIS WEB SITE ASSUME NO RESPONSIBILITY OR LIABILITY FOR ANYTHING THAT MAY ARISE FROM ANYONE ATTEMPTING TO DUPLICATE THIS PROJECT.

The ABS system in the 1990 through 1993 Imperials was somewhat less than something worthy of being associated with the name Imperial. The system was crude and primitive by today's standards and often failed, leaving the vehicle with no brake boost, and the perception of "no brakes," often resulting in serious front end collisions that would invariably spell the end of the vehicle. This says nothing about the doubtless property damage and human casualties that this poorly designed system has been responsible for.

Since the 1990-93 Imperial is such a joy to drive, I decided to retrofit the failing ABS system on my 1990 Imperial with the same old non-ABS style braking system that is found in the Imperial's sister cars, the New Yorker and Dynasty. This type of braking system has been tried and proven effective and reliable for decades. Parts for this retrofit are affordable and readily available new, rebuilt or from a salvage yard.

The project started by removing the massive ABS master cylinder and pump.

There are four 13mm nuts under the dash inside the car that hold the master cylinder in. Three are fairly easy to access and one is next to impossible to get to. There is also a clip that retains the pin that holds the brake pedal to the master cylinder ram. Once the four nuts and the pin were removed, I had to remove all the electrical connectors and four brake lines from the master cylinder. The brake lines are difficult to access and rarely come undone without twisting off the brake line. Since I was not saving the master cylinder and I love using my sawzall, I simply cut off the protrusions form the master cylinder where the brake lines were attached. Had I known what I would have to do later, I would have just cut the brake lines close to the master cylinder instead.

With the master cylinder out, I removed the ABS pump. There is only one small bolt holding the pump in. I bent the shroud up and out of the way, removed the bolt and the pump and shroud both came off easily.

Next I had to go to the salvage yard to get a proportioning valve. The ABS does not use an external proportioning valve but rather controls all that in the ABS master cylinder itself. I think just about any K car proportioning valve will do. Mine came from an earlier K car and it works just fine. I had to buy a couple fittings to adapt two of the proportioning valve ports to the 3/16" brake lines. I bought a flaring tool and some fittings so I could make the Imperial's brake lines fit directly into the proportioning valve and thereby negate the need to replace any of the metal brake lines on the car.

Once I had the brake lines flared, I screwed each one into the proportioning valve and mounted the valve to the frame rail of the car just where it came off the donor car. I left off the two lines going to the master cylinder for the time being.

Next was to install the booster. It is a tight fit to get the booster between the strut tower and the engine's intake system but it can be done. I had to lift a section of large wiring harness so the booster would sit tight against the firewall. I installed the four nuts onto the new booster from under the dash of the car. The climate control system has a small vacuum line going to the intake manifold and this is where the brake booster is to be attached. The climate control line is to be reattached to the check valve on the brake booster.

Next, I test fitted the new master cylinder onto the new power brake booster. I used this test fit to position and bend the new brake lines I bought to go from the master cylinder to the proportioning valve. When I had them bent in an appropriate way, I took the master cylinder out again and attached the brake lines to the proportioning valve. I also connected the electrical sensor wire to the proportioning valve and coiled up the lead wire for future connection to the appropriate circuit.

I installed the master cylinder again and bolted it to the booster. Then I could screw the two brake lines into the master cylinder.

The next step was to change the brake pedal to the non-ABS style (Dynasty, New Yorker etc). This is only needed if you are changing from the Bendix type ABS. If you have the Bosch ABS system, your existing brake pedal will line up just fine.

The brake pedal that is installed on the Bendix type ABS system does not line up with the vacuum booster shaft. The pedal is removed by removing the 15mm nut from a pivot pin (inboard end). The pin is round on the outboard end but has two flat spots in it that will accommodate a 7/16" wrench.

Bleeding the brakes took a long time but I finally got all the air out and the brakes were firm. Be sure to start with the wheel farthest from the master cylinder and work your way to the master cylinder. (right rear, left rear, right front, left front)

At this point, there are a few things to watch for.

• Effectiveness of front brakes as compared to the rear. The proportioning valve seems to do a nice job here. I've noticed no adverse braking issues with the system.
• Brake fluid leaks, particularly where the old brake lines were flared. This happens often if you don't tighten the brake lines to the proportioning valve.
• Pedal travel to be sure there are no brakes dragging. It's a fine line between having enough pedal travel to have braking effectiveness and being certain the brakes don't drag at all. To adjust this, you need to pull the master cylinder off the booster (this is why you want to put a couple of nice curls in the brake lines on the master cylinder). The little rod that protrudes from the booster is threaded. Turning this rod clockwise will give you more pedal travel and possibly reduce braking effectiveness. Turning the rod the other way will give you more braking effectiveness but could lead to dragging brakes.

I adjusted the booster rod length a number of times to get the proper pedal travel. This is extremely important! Too much travel and you will not have enough braking power, too little travel and the brakes will be dragging as you drive. Dragging brakes can cause premature wear or even a wheel fire!