Service Procedure
The following procedure provides instructions for inspecting, and if necessary, replacing the hydraulic brake fluid pipes that go to the rear brakes at THREE different locations on the Cadillac XLR and ONE location on the Chevrolet Corvette.^ On the XLR, two of the locations are on the long pipes that go from the ABS module in the engine compartment, along the left frame rail and driveline tunnel to the rear frame (cradle). The third location is the crossover pipe that goes across the rear cradle from the left side of the vehicle to the right side.
^ On the Corvette, the only location is the crossover pipe that goes across the rear cradle from the left side of the vehicle to the right side.
Inspection
Front Brake Pipe Inspection - Cadillac XLR Only
1. Raise the vehicle on a suitable hoist and support as necessary.
2. In the front of the vehicle, locate the two REAR brake pipes in the area of the left exhaust manifold and converter assembly (3). The two pipes will be running along the inside of the frame rail and are wrapped in a silver heat resistant material (1). In between the two sections of the heat resistant material is a plastic retaining clip (2). This clip should be attached to a stud located on the frame rail.
^ If the retaining clip IS attached to the frame rail, no further inspection is needed in this area of the vehicle. Proceed to Step 4 in this section.
^ If the retaining clip is NOT attached to the frame rail, inspect to see if the pipes (and heat resistant material) are, or have been contacting the exhaust manifold and converter assembly. If there IS evidence of contact and the black coating on the pipe(s) is worn through (you can see the bare steel) then the front section of brake pipes must be replaced. Before replacing the pipes, continue onto the section titled, "Rear Brake Pipe Inspection".
^ If the bare steel CANNOT be seen, then proceed to the next step.
3. Reposition the retaining clip as necessary and install it on the stud located on the frame rail. Press firmly into place.
4. Remove any dirt or foreign material from the frame rail in the area of the plastic retainer.
5. Trim a piece of adhesive cover (P/N 25649654) to a size of approximately 100 mm by 125 mm (4 in by 5 in).
6. Remove the backing material from the adhesive cover and apply the material (1) over the retaining clip and brake pipes and press firmly to the frame rail.
7. Proceed to the section titled, "Rear Brake Pipe Inspection".
Rear Break Pipe Inspection - Cadillac Only
1. Towards the rear of the vehicle where the left exhaust pipe (1) bends upward to go over the drive axle, locate the two rear brake pipes (2). The two pipes will be running along the left inside of the driveline tunnel. They DO NOT have any heat resistant material.
2. Once the brake pipes have been located, inspect for clearance to the left exhaust pipe (1) in the area just forward of where the brake pipes (2) bend downward to connect to the crossover and left rear flexible hose.
^ If the clearance (space) between each brake pipe and the exhaust pipe is 40 mm (1.5 in) or more, no further inspection or repair is needed in this area of the vehicle. Proceed to the section titled, "Rear Brake Crossover Pipe Inspection".
^ If the clearance is LESS than 40 mm (1.5 in), but neither pipe is contacting the exhaust pipe, bend the pipe(s) as necessary to obtain the necessary clearance. Proceed to the section titled, "Rear Brake Crossover Pipe Inspection".
^ If the pipe(s) ARE contacting, or there IS evidence that the pipe(s) have been contacting the exhaust pipe, inspect to see if the black coating on the brake pipes is worn through (you can see bare steel). If the black coating has worn through, then the rear section of brake pipes must be replaced. Before replacing the pipes, continue on to the section titled, "Rear Brake Crossover Pipe Inspection".
^ If the bare steel CANNOT be seen, then bend the pipes as necessary to obtain the necessary clearance and proceed to the section titled, "Rear Brake Crossover Pipe Inspection".
Rear Brake Crossover Pipe Inspection - Cadillac XLR and Chevrolet Corvette
1. Locate the crossover pipe (1) in the rear frame (cradle) assembly. The pipe connects the rear brake pipe coming from the front of the vehicle to the flex hose going to the right rear brake caliper.
2. Once the pipe has been located, inspect for contact to the rear cradle at the locations shown in the illustration. Also inspect for contact to the boss on the rear differential.
^ If there is evidence of contact at any of the locations shown (2) and the black coating on the pipe IS worn through (you can see bare steel), then the crossover pipe must be replaced. Before replacing the pipe proceed to the next step for removal of the boss (3) on the differential.
^ If there is evidence of contact but the bare steel CANNOT be seen, then the crossover pipe does NOT need to be replaced. Bend the pipe as necessary to eliminate any contact points with the cradle. Proceed to the next step for removal of the boss (3) on the differential.
3. Important: Regardless of whether the crossover pipe is contacting the boss on the differential or not, the boss must be removed.
4. Important: Because the clearance is very limited, it will be necessary to use a hacksaw blade without the handle in the next step.
5. Wrap several layers of heavy tape around one end of a hacksaw blade (1) to form a handle (2).
Notice:
DO NOT use power tools for removing the boss because of the close proximity of the brake pipe.
Important:
It is not necessary to cut off the boss flush with the differential case. It is acceptable to cut the boss off across or through the threaded hole.
6. Standing under the rear of the vehicle and facing towards the front, insert the hacksaw blade (1) between the bottom of the cradle and the top of the leaf spring so that it is in contact with the boss (2) on the differential. The teeth on the blade should be facing towards the right rear wheel.
7. Carefully work the blade back and forth to cut off the boss (1).
8. If any brake pipes require replacement, proceed to the appropriate brake pipe replacement procedure in this bulletin. If no brake pipes require replacement, no further action is required. Proceed to the next step.
9. Lower the vehicle.
Brake Pipe Replacement
Front Brake Pipe Replacement - Cadillac XLR Only
Tools Required
J 45405 Brake Pipe Flaring Kit
1. Loosen and remove the nuts (2) from the studs attaching the exhaust pipes to the exhaust manifolds.
2. Loosen the exhaust pipe to muffler band clamps (2, 5).
3. Remove the exhaust pipe hanger lower bolts (3).
4. Slide the mufflers out from the rear hangers (1).
5. Separate the exhaust pipes from the mufflers.
6. Remove the exhaust pipes and mufflers.
7. Remove the thirty-six bolts that attach the driveline tunnel closeout panel to the underbody and remove the panel.
8. Unclip the rear brake pipes from the retainers in the driveline tunnel.
Important:
When cutting off the brake pipes in the next steps, the cuts on the pipes should be staggered about 50 mm (2 in) from each other.
Important:
Before cutting the pipes make a note or mark which pipe is the upper. This will be used when reassembling the pipes later in this procedure.
Important:
Inspect the length of the new brake pipes to determine "approximately" where to cut the old pipes under the vehicle in the next step. DO NOT cut the pipes too short.
9. Using the tubing cutter contained in J 45405, Brake Pipe Flaring Kit, cut the two rear brake pipes off under the vehicle.
10. Release the brake pipes going to the front of the vehicle from the retaining clips.
11. Lower the vehicle.
12. Open the hood.
13. Remove the engine cover (sight shield).
14. Partially drain the radiator.
15. Remove the upper radiator hose from the radiator.
16. Remove the bolts attaching the surge tank and reposition the tank so there is access to the top of the ABS modulator valve.
17. Remove the two bolts attaching the lower intermediate shaft to the column.
18. Remove the pinch bolt attaching the intermediate shaft to the steering gear.
19. Slide the lower intermediate shaft from the column and remove the intermediate shaft.
20. Disconnect the fittings for the two rear brake pipes from the ABS modulator valve.
Important:
When removing the brakes pipes in the next step, it will be necessary to rotate the assembly to clear various components. It is NOT necessary to bend the pipes.
21. While noting the routing location, carefully remove the complete pipe assembly from the vehicle.
22. Install the complete new pipe assembly into the vehicle following the same routing.
23. Connect the fittings on the new pipes to the ABS modulator valve.
Tighten
Tighten the fittings to 16 N.m (12 lb-ft).
24. Install the intermediate shaft and bolts.
Tighten
^ Tighten the lower pinch bolt to 34 N.m (25 lb-ft).
^ Tighten the two upper bolts to 48 N.m (35 lb-ft).
25. Reposition the surge tank and install the attaching fasteners.
Tighten
Tighten the attaching fasteners to 8 N.m (71 lb in).
26. Connect the upper radiator hose to the radiator.
27. Fill the cooling system.
28. Install the engine cover.
29. Raise the vehicle.
30. Confirm the alignment of the new pipes to the existing rear pipes and cut the new pipes as necessary, taking into consideration the staggered cut made earlier on the rear pipes.
31. INSTALL ONE FLARE NUT ON EACH PIPE and, following the instructions contained in J 4540, make all the necessary flares.
32. Using the unions included with the new front pipes, align the pipes using the mark made earlier and connect the pipes to the rear pipes.
Tighten
Tighten the fittings to 18 Nm (13 lb-ft).
33. Secure the brake pipes in the retainers.
34. Remove any dirt or foreign material from the frame rail in the area of the plastic retainer that is located near the left engine exhaust manifold.
35. Trim a piece of adhesive cover (P/N 25649654) to a size of approximately 100 mm by 125 mm (4 in by 5 in).
36. Remove the backing material from the adhesive cover and apply the material (1) over the retaining clip and brake pipes and press firmly to the frame rail.
Important:
When installing the bolts in the next step, the first bolt to be installed must go in the one ROUND locating hole in the panel. The remaining 35 bolts can then be installed in the SLOTTED holes.
37. Position the driveline tunnel closeout panel to the underbody and install the bolts.
Tighten
Tighten the bolts to 10 N.m (88 lb-in).
38. Position the mufflers over the rear axle.
39. Connect the exhaust pipes to the mufflers and then to the converters.
40. Connect the mufflers to the hangers.
41. Install the exhaust pipe hanger lower bolts.
Tighten
Tighten to 50 N.m (37 lb-ft).
42. Install the nuts on the converter studs.
Tighten
Tighten to 20 N.m (15 lb-ft).
43. Position and install the exhaust pipe to muffler band clamps.
Tighten
Tighten to 44 N.m (32 lb-ft).
44. Inspect for clearance to the left exhaust pipe in the area just forward of where the brake pipes bend downward to connect to the crossover and left rear flexible hose. The clearance should be 40 mm (1.5 in). Bend the pipe(s) as necessary to obtain the necessary clearance.
45. Lower the vehicle.
46. Bleed the brake system as necessary.
Rear Brake Pipe Replacement - Cadillac XLR Only
1. Raise the vehicle on a suitable hoist and support as necessary.
2. Remove the exhaust pipe nuts (2) at the converters (5).
3. Loosen the exhaust pipe to muffler band clamps (2, 5).
4. Remove the exhaust pipe hanger lower bolts (3).
5. Slide the mufflers out from the rear hangers (1).
6. Separate the exhaust pipes from the mufflers.
7. Remove the exhaust pipes and mufflers.
8. Remove the thirty-six bolts that attach the driveline tunnel closeout panel to the underbody and remove the panel.
9. Unclip the rear brake pipes from the retainers in the driveline tunnel.
Important:
When cutting off the brake pipes in the next steps, the cuts on the pipes should be staggered about 50 mm (2 in) from each other.
Important:
Inspect the length of the new brake pipes to determine "approximately" where to cut off the old pipes under the vehicle in the next step. DO NOT cut the pipes too short.
Important:
Before cutting the pipes make a note or mark which pipe is the upper. This will be used when reassembling the pipes later in this procedure.
10. Using the tubing cutter contained in J 45405, cut the two rear brake pipes off under the vehicle.
11. Disconnect the rear pipe from the crossover pipe at the union (1).
12. Remove the clip that attaches the left rear flexible brake hose (2) and rear brake pipe to the bracket.
13. Disconnect the rear brake pipe from the left rear flexible hose (2).
14. Remove the complete rear brake pipe assembly from the vehicle.
15. Install the complete new rear brake pipe assembly to the vehicle.
16. Connect the rear pipe to the left rear flexible hose.
Tighten
Tighten fittings to 18 N.m (13 lb-ft).
17. Position the flexible brake hose and rear pipe to the bracket and install the retaining clip.
18. Connect the other rear pipe to the crossover pipe at the union.
Tighten
Tighten the fittings to 18 Nm (13 lb-ft).
19. Confirm the alignment of the new pipes to the existing front pipes and cut the new pipes as necessary taking into consideration the staggered cut made earlier on the front pipes.
20. INSTALL ONE FLARE NUT ON EACH PIPE and, following the instructions contained in J 45405, make all the necessary flares.
21. Using the unions included with the new rear pipes, align the pipes using the mark made earlier and connect the pipes to the front pipes.
Tighten
Tighten the fittings to 18 Nm (13 lb-ft).
22. Secure the brake pipes in the retainers.
Important:
When installing the bolts in the next step, the first bolt to be installed must go in the one ROUND locating hole in the panel. The remaining 35 bolts can then be installed in the SLOTTED holes.
23. Position the driveline tunnel closeout panel to the underbody and install the bolts.
Tighten
Tighten the bolts to 10 N.m (88 lb-in).
24. Position the mufflers over the rear axle.
25. Connect the exhaust pipes to the mufflers and then to the converters.
26. Connect the mufflers to the hangers.
27. Install the exhaust pipe hanger lower bolts.
Tighten
Tighten the bolts to 50 N.m (37 lb-ft).
28. Install the nuts on the converter studs.
Tighten
Tighten the studs to 20 N.m (15 lb-ft).
29. Position and install the exhaust pipe to muffler band clamps.
Tighten
Tighten the clamps to 44 N.m (32 lb-ft).
30. Inspect for clearance to the left exhaust pipe in the area just forward of where the brake pipes bend downward to connect to the crossover and left rear flexible hose. The clearance should be 40 mm (1.5 in). Bend the pipe(s) as necessary to obtain the necessary clearance.
31. Lower the vehicle.
32. Bleed the brake system as necessary.
Rear Brake Crossover Pipe Replacement -- Cadillac XLR and Chevrolet Corvette
1. Raise the vehicle on a suitable hoist and support as necessary.
2. Remove the exhaust pipe nuts (2) at the converters (5).
3. Loosen the exhaust pipe to muffler band clamps (2, 5).
4. Remove the exhaust pipe hanger lower bolts (3).
5. Slide the mufflers out from the rear hangers (1).
6. Separate the exhaust pipes from the mufflers.
7. Remove the exhaust pipes and mufflers.
8. Remove the four nuts (4) attaching the transaxle/differential mount to the rear crossmember.
9. Using a transmission jack under the transmission, carefully raise the differential assembly to gain access for removal of the crossover brake pipe.
10. Disconnect the crossover brake pipe at the union (1) on the left side of the vehicle.
11. Release the two retainers that attach the crossover pipe to the crossmember.
12. Release the clips attaching the wiring harness to the crossmember.
13. Remove the clip that attaches the right rear flexible brake hose and crossover pipe to the bracket.
14. Disconnect the crossover brake pipe from the flexible brake hose.
15. Remove the crossover brake pipe from the vehicle.
16. Install the new crossover brake pipe to the vehicle.
17. Connect crossover pipe to right rear flexible brake hose.
Tighten
Tighten to 18 N.m (13 lb-ft).
18. Install the clip that attaches the right rear flexible brake hose and crossover pipe to the bracket.
19. Connect the crossover brake pipe to the union on the left side of the vehicle.
Tighten
Tighten to 18 N.m (13 lb-ft).
20. Attach the two crossover pipe to crossmember retainers.
21. Attach the wiring harness to the crossmember with the clips.
22. Lower the differential assembly.
23. Install the four nuts that attach the transaxle/differential assembly mount to the crossmember.
Tighten
Tighten the nuts to 50 N.m (37 lb-ft).
24. Position the mufflers over the rear axle.
25. Connect the exhaust pipes to the mufflers and then to the converters.
26. Connect the mufflers to the hangers.
27. Install the exhaust pipe hanger lower bolts.
Tighten
Tighten the bolts to 50 N.m (37 lb-ft).
28. Install the nuts on the converter studs.
Tighten
Tighten the studs to 20 N.m (15 lb-ft).
29. Position and install the exhaust pipe to muffler band clamps.
Tighten
Tighten to 44 N.m (32 lb-ft).
30. Lower the vehicle.
31. Bleed the brake system as necessary.