2 - Front Brake Rotor, modified. Available from The Streetrod Manufacturing Company (TSM).
1 - Caliper bracket set. Available from TSM, or you can fabricate your own.
1 - Flexible caliper line kit. Available from TSM, P/N 3702.
1 - Rear disc brake caliper, left side, with parking brake cable bracket and actuator arm, 1979-1985 Eldorado/Riviera/Toronado or 1980-1985 Seville. Available from TSM or you can obtain rebuildable cores from a wrecking yard and rebuild (recommended).
1 - Rear disc brake caliper, right side, with parking brake cable bracket and actuator arm, 1979-1985 Eldorado/Riviera/Toronado or 1980-1985 Seville. Available from TSM or you can obtain rebuildable cores from a wrecking yard and rebuild the wrecking yard cores (recommended).
4 - Rear caliper mounting bolts.
1 - Rear disc brake pad, set, 1979-1985 Eldorado/Riviera/Toronado or 1980-1985 Seville. Semi-metallic lining recommended.
2 - Rear pad anti-rattle springs. These should be on the calipers you get from the wrecking yard, also available new either separately or in a hardware kit for the calipers.
2 - Rear parking brake cable, custom with 38.75" (OD) between housing mount points and 47.25" (ID) between cable ends. Available from Control Cable, Inc.
1 - Brake proportioning valve, 1977-1978 Seville with 4-wheel disc. Available from wrecking yard.
1 - Brake master cylinder, 1977-1978 Seville with 4-wheel disc. Available from auto parts stores or rebuildable cores available from wrecking yard.
1 - Brake vacuum booster and mounting nuts, 1983-1987 Regal/Cutlass (Brougham or Supreme) RWD 4-door models.
2 - Axle shaft seal.
1 - Differential cover gasket.
1 - 1" cotter pin.
A/R - DOT 3/4/5 high-quality brake fluid. (I like to use Valvoline synthetic fluid or Castrol LMA GT fluid.)
A/R - SAE 90 or SAE 85W-140 EP hypoid gear oil. If truck has a limited-slip differential a friction modifier (limited-slip additive) is necessary as well.
2 - Axle shaft bearings.
1 - 3/8" bleed screw for proportioning valve. (you can re-use one of the rear wheel cylinder bleed screws for this purpose if they are not too disfigured.)
A/R - 3/8" vacuum hose
1. If getting calipers from a wrecking yard ensure that the parking brake ratchet mechanisms in the pistons are not broken or distorted in any way. Disassemble the calipers and inspect the ratchet mechanisms in the pistons before leaving the wrecking yard. Broken or distorted parking brake ratchets render the calipers no good and replacement pistons are very expensive. Also, check the bores in the calipers for pits. Severe pitting renders the calipers useless.
2. If getting calipers from a rebuilding source, you will need to obtain the bracketry for the parking brake actuator (cable end bracket, actuator arm) from a wrecked car.
3. Most mechanics don't understand the presence of the rear pad damping springs and forget to re-install them when doing a brake job. If your wrecking yard calipers don't include those damping springs, replacements are available at most parts stores.
4. It is imperative that the caliper mounting bolts be straight and the surface of the pins smooth. If your wrecking yard bolts are not straight and smooth, replacements are available at most parts stores.
5. The mid-'80s GM RWD mid-size (Regal, Cutlass) booster's actuator rod clevis is metric and its ID is larger than the OD of the pin in the factory power brake linkage for the Blazer/Jimmy. Acceptable remedies include replacing the pin with a larger OD pin, inserting a suitable steel bushing into the hole, or welding up and re-drilling the clevis hole to 3/8".
6. The mid-'80s GM RWD mid-size (Regal, Cutlass) booster's actuator rod clevis is narrower than the factory power brake booster's clevis is for the Blazer/Jimmy. Acceptable remedies include installing two 3/8" ID, 3/4" OD, 1/16" thick thrust bushings (available at some hardware stores like Orchard Supply or at bearing distributors) or welding up the surface on both sides and machining to proper thickness.
7. The mid-'80s GM RWD mid-size (Regal, Cutlass) booster uses metric studs (10mm), so it is imperative to get the metric locking nuts for the booster when you obtain the booster.
8. The Seville proportioning valve has two outlets for the front brake circuit and the Blazer has only one hard line that screws into its original combination valve. Acceptable remedies include re-plumbing the front brake circuit so that each caliper has separate lines leading to the proportioning valve or removing the compression fitting from the valve body and installing a bleed screw in its place (recommended - the Blazer/Jimmy's original combination valve has a bleed screw in the same position and that screw fits in a properly modified Seville proportioning valve).
9. The Seville master cylinder's reservoir cap is much different than the Blazer/Jimmy's, so ensure that you obtain a proper reservoir cap with your master cylinder.
10. It is recommended that the vapor filter on the Regal/Cutlass power brake booster's vacuum line be retained in order to reduce possible internal damage to the booster from fuel vapors.
11. If you do not have convenient access to a welding tool, drive to a competent welder and have the hard mounting points for the flexible lines welded to the rear axle. The most convenient place is just outboard of the most outboard clips that pin the brake lines to the axle housing, arranged vertically.
12. Try never to touch the friction surfaces of any rotors or pads. If you do touch them, immediately wash the rotor or pad clean using a residue-free brake parts cleaner.
13. The parking brake cable housings in the late disc brake cars are metric, so you will need to machine the cable end bracket that bolts to the caliper to accept a 9/16" parking brake cable housing.
1. Park truck on flat, level surface. Block the front wheels. Place drain pan under rear differential and remove differential cover to drain differential housing.
2. Remove cover from master cylinder. Using a suitable siphon, empty as much fluid as possible from reservoirs. Replace cover on master cylinder.
1. Remove pedal rearward travel limiting plate from under the steering column. Lower steering column by removing two bolts fastening steering column support to dashboard.
2. Remove cotter pin from brake pedal lever. Discard. Remove nut from retaining bolt. Remove retaining bolt from brake pedal. 3. Using suitable line wrenches, loosen brake pressure supply lines at junctions to the combination switch and master cylinder. Detach the output lines from the combination valve.
4. Remove bleed screw and brake warning light lead from combination valve. Insert into Seville proportioning valve. Remove combination valve from truck, leaving brake pressure supply lines loosely connected to master cylinder. Remove vacuum check valve and vacuum supply hose from booster.
5. Remove front supply line from master cylinder and install loosely onto proportioning valve front input circuit. Remove rear pressure supply line and install loosely onto proportioning valve rear input circuit.
6. Remove forward (lower) booster support brace from firewall and booster and place aside. Remove remaining bolt retaining master cylinder to booster. Remove proportioning valve bracket and place aside. Remove master cylinder and discard (or place aside to return as a rebuildable core).
7. Remove cotter pin from brake actuator linkage lower pivot axle and discard. Drive lower pivot axle out of its mount points and place aside.
8. Remove rear (upper) booster support brace from firewall and booster and place aside. Remove remaining 3 nuts retaining booster to booster support brackets and remove booster. Remove brake actuator linkage from booster. Discard booster.
9. Using 25/64" or 10mm twist drill, enlarge the four holes in the booster support brackets into which the booster's mounting studs insert. Loosen 4 nuts and one bolt retaining booster support brackets to firewall.
Note: If you wish to paint the booster support brackets, remove them and paint them at this time and skip to the section on disassembling the rear axle while the paint dries.
10. Install brake actuator linkage on master cylinder actuator rod.
Note: The previous step assumes you have already modified the linkage or booster clevis for proper fit through pin replacement/drilling up side plates, bushing clevis, or welding/drilling clevis and adding any thrust bearings necessary.
11. Slide booster/actuator assembly into place. Install three self-locking metric booster retaining nuts onto the two inboard studs and lower outboard stud. Install rear (upper) booster support brace onto the upper outboard booster stud and its mounting stud on the firewall. Install retaining nuts. Torque booster mounting nuts to 24 lb./ft. Torque booster bracket nuts to 20 lb./ft. Torque booster bracket bolt and rear (upper) booster support brace nut (on firewall) to 12 lb./ft.
12. Insert brake pedal pivot pin into actuator linkage. Place thrust washer on pivot pin and insert pivot pin into brake pedal. Screw self-locking (crimp-type) retaining nut onto pivot pin and snug up. Do not torque or install cotter pin at this time because linkage will more than likely need to be adjusted.
13. Slide booster pushrod into the face of the booster if it is not already present. Slide new master cylinder onto booster studs. Slide proportioning valve bracket onto mounting studs. Install inboard mounting nut and snug up. Slide lower (forward) support brace onto outboard stud and fit it to the firewall.
Note: The lower brace will need to be modified in order to fit between the booster and firewall.
14. Torque master cylinder retaining nuts to 24 lb./ft. Torque forward brace retaining screw to 12 lb./ft. Install brake hard lines between master cylinder and proportioning valve and leave loose. Install chassis pressure supply lines onto proportioning valve and leave loose. Mount proportioning valve on its support bracket and torque the self-locking (crimp-type) nuts to 15 lb./ft. Tighten brake hard lines and bleed screw. Partially fill master cylinder reservoir and place cap loosely on it.
15. Install vacuum check valve and hose on booster. Cut the vacuum supply hose in a suitable place and install vapor filter.
Note: Now is a good time to replace that old, brittle, cracked booster vacuum hose with a new one.
1. Loosen rear wheel nuts. Jack up rear end of truck. Support rear axle on stands. Place transmission in neutral and release parking brake.
2. Remove rear wheels. Remove rear brake drums. Clean brake residue off of brake components. Remove brake shoes. Remove parking brake cables.
3. Rotate differential so that pinion shaft locking bolt is accessible. Unscrew and remove pinion shaft locking bolt. Remove pinion shaft.
4. Remove axles by sliding them into the axle housing to expose C-clips, remove C-clips from inboard ends of axles, and slide axles out of axle housing. Remember to keep track of which axle belongs on which side of the axle housing!
5. Disconnect pressure lines from wheel cylinders. Unbolt and remove drum backing plates from axle housing. Discard.
Note: At this time it is suggested that axle shaft seals be removed and replaced with new ones.
1. Remove brake pressure supply lines from the most outboard clips on the rear axle. Bend forward and around the front of the spring perch, then center with the holes in the previously welded-on hard mounting points for the flexible lines. Slide reverse flare to AN-3 adaptors into the flexible line hard pointe. Install reverse flare to AN-3 adaptors onto brake lines and install retaining clips. Tighten brake line nuts into adaptors.
2. Slide axle shafts back into axle housing, being careful not to drag the unmachined surfaces or splines of the shafts on the seals or bearings. Install C-clips into their grooves at the ends of the axles and slide axles back out as far as the C-clips will allow. Install pinion shaft. Install pinion shaft locking bolt and torque to 20 lb./ft. Install differential cover and torque to 23 lb./ft. Fill differential housing with proper gear lube. If the differential is a limited-slip type differential, use an approved limited-slip additive as well.
3. Wash hands. Slide brake rotor over axle flange. Ensure that all studs fit their holes and that pilot hole in rotor fits over the stepped pilot on the axle flange (often, the rotor needs to be chamfered to fit over the step in the pilot). Tighten two lug nuts onto opposing studs. Wash rotor clean of any preservative material.
4. Install caliper mounting brackets onto axle housing flange. Temporarily install loaded caliper onto caliper brackets and ensure that calipers are properly aligned with rotor faces (i.e. pads are in planes parallel to the plane of the face of the rotor). If the caliper is not properly aligned, the caliper and mounting bracket need to be removed and the mounting bracket need to be altered in order to get the caliper aligned.
5. Once caliper is properly aligned, torque caliper brackets to 35 lb./ft. (bolts oiled). Install caliper. Ensure bleed screw is tight on caliper.
6. Install one crush washer onto banjo bolt for flexible brake line, then install banjo over that and another crush washer over that. Insert banjo bolt into brake caliper and make finger-tight. Screw female AN end of flexible hose onto the reverse flare to AN-3 adaptor and tighten. Arrange hose so that there is little tension on it and tighten banjo bolt to 18 lb./ft.
7. Repeat steps 3 through 6 for other side.
8. Install parking brake cable housings on frame. Connect new rear parking brake cables to original intermediate parking brake cable.
1. Half-fill the master cylinder reservoirs with clean brake fluid. Using a rubber mallet, lightly and rapidly rap on the front of the master cylinder to expel bubbles until the number and size of bubbles becomes very small.
2. Fill rear reservoir to half capacity with clean brake fluid again. Lightly pump brake pedal two or three times with very slow, short strokes. Lightly and rapidly rap on front of master cylinder again, noting bubble size and frequency. Stop when number and size of bubbles diminishes to an insignificant amount and size.
3. Fill rear reservoir with clean brake fluid. Rotate parking brake actuator arms in their "apply" directions (toward the front of the truck) until the pads contact the rotors. Remove actuator arms and reposition if there is not sufficient travel available and rotate some more. If actuator arms stop very close to the front of the caliper, remove and reposition sot that they are closer to the rear stops that're cast into the calipers. Install actuator arm return springs and install parking brake cable housing to stationary housing mount. Install rear parking brake cable onto actuator arm. Adjust forward parking brake cable so that there is slight tension (insufficient to move parking brake actuator arms) in the parking brake cables.
4. Loosen bleed screw on right rear caliper. Remove caliper from its bracket and hold in such a fashion so that the galley feeding the bleed screw is at the top of the caliper's bore (bleed screw's axis of rotation will be horizontal). Loosen bleed screw and rap on caliper lightly and rapidly with a rubber mallet. Observe the bleed screw for fluid and air discharge. Stop and snug up the bleed screw and check the master cylinder rear reservoir frequently for fluid level and refill as necessary. When pure fluid begins to come out of bleed screw, snug the bleed screw up and install the caliper. Fill master cylinder rear reservoir.
5. Repeat step 4 for left side caliper. Torque caliper mounting pins to 35 lb./ft.
6. Adjust the brake pedal height so that there is between 0.06" and 0.25" play at the center of the brake pad (0.125" preferred) with brake primary pushrod connected. Adjustment is made by loosening the jam nut on the primary pushrod and lengthening or shortening the primary pushrod. Once this amount of play has been adjusted in, torque brake relay rod clevis nut to 30 lb./ft. Install cotter pin into bolt. Set locking nut on brake primary pushrod to retain adjustment. Adjust brake light switch to close at between 0.38" and 0.64" of pedal travel.
7. Fill master cylinder front reservoir. Bleed front calipers in the "normal" fashion while frequently checking the front reservoir to ensure that it does not get drained. After brakes are sufficiently bled, refill master cylinder reservoir and affix cover to reservoir.
8. Install rear tires and lug nuts. Set parking brake. Torque lug nuts to 75 lb./ft. Set truck on ground. Release and fully apply parking brake at least 6 times. Carefully test drive at low speeds, noting any pulling or strange application of brakes and re-bleed as necessary. If brake application sequencing and balance seem appropriate, increase braking pressures to ensure that brakes will not lock up unduly. Re-bleed brakes as necessary. Enjoy!
TSM - The Streetrod Manufacturing Company
4321 Willow Creek Rd.
Castle Rock, CO 80104-9766
303-688-6882
Control Cables
13230 E. Firestone Rd., Unit K
Santa Fe Springs, CA 90670-7075
562-802-1122
Disclaimer: Some of the operations and situations noted in these articles may lead to dangerous or hazardous conditions. I take no responsibility for anything you do as a result of seeing these articles. The information presented herein is intended strictly for informational and entertainment purposes only.
Copyright 1998 Steven Chin. None of the material presented on this site may be reproduced without the express consent of its' copyright holder.