How to install 40mm Viper Rear Brake Calipers

[Tom F&L GoR]

I'm putting these instructions here for all to see and for eventual inclusion in the Illustrated Guide. This will give you step by step instructions, a list of the tools, and pictures to swap rear calipers on your own. Any comments or questions, please ask so that when this thread is archived everything is included.


Tools needed:

• 15mm wrench or socket
• 6mm Allen wrench or socket
  • The 1/4 Allen may seem like it should fit, but it is really too large
  • 6mm is 0.236 inches vs. 0.250 inches.
• 10mm wrench for bleeder screw
• Vise-Grip pliers
• Brake fluid
• Rags to catch brake fluid

1. Place wheel chocks in front of and behind a front wheel so the car cannot roll.

2. Release parking brake.

3. Jack up rear corner of car and remove wheel.

4. Brake Pin and Retaining Spring

a) Use a drift or punch (something not larger than about 0.110” diameter) and small hammer to drive out the brake pin. The brake pin is removed by tapping it from the inside (from closer to the differential) out of the caliper body (towards you.) You’ll see the head of the brake pin pop out of the hole.

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b) Catch the anti-rattle spring before you pull the pin all the way out!

c) You might be able to wiggle the outer brake pad out now, but you don’t need to.
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5. Remove brake cable

a) DO NOT UNSCREW THE BRAKE ARM TO REMOVE THE CABLE! The service manual advises you to do so, but the internal parts do not have enough strength to withstand the torque of trying to unscrew a rusty or sticking bolt. You have a high likelihood of causing damage.

b) Use Vise-Grips to grab the ball end of the brake cable.

c) Pull the ball (in direction to pull on the cable.) The cable should have enough slack to unseat it and unhook the cable from the arm.



d) When cable ball is unhooked, pull the cable sheath out of the hole in the caliper. (Towards the right in the picture below.) On Gen 1 cars there is a metal wire clip holding the sheath to the upright. On Gen 2 cars there doesn’t seem to be anything holding the cable sheath.

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6. Remove brake hose

a) Locate the brake hose support bracket. It is mounted to the caliper with a 15mm bolt as shown in the picture above. Unscrew and remove bolt

b) Locate the end of the brake hose (bottom of caliper) and unscrew and remove banjo bolt with a 15mm socket. Discard the copper washers but save the bolt. Hang the brake hose on the suspension as high as possible to prevent the brake fluid from draining the master cylinder.
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7. Remove caliper

a) Locate lower attaching bolt (the head of the bolt faces towards the differential) and remove with a 15mm socket.

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b) Locate upper attaching bolt and remove with a 6mm allen head. A ¼” allen head may fit, but then be careful you have enough engagement or you will round off the edges.

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c) The caliper can now be removed from the car. Most likely the edges of the rotor will catch on the brake pads. Use a long screwdriver under the bridge of the caliper and over the vanes of the rotor to push the caliper off.
d) For reference, the arms the caliper attaches to are the ones that are cut off in the “big brake” installations.

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8. Install new 40mm Caliper

a) Hang the new caliper in place using the upper 6mm attaching bolt. Before tightening, start the lower 15mm attaching bolt.

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b) When both attaching bolts are engaged, torque upper to 24 ft-lbs (32 N-m) and lower to 38 ft-lbs (51 N-m).

c) Remove rotor – if the caliper seems to prevent this, pull the caliper body towards you. It should slide in and out to allow the rotor to be removed.

d) Position the inner brake pad, and then reinstall the rotor.

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e) Position the outer brake pad. Make sure the ends of the brake pads hook over the caliper or the holes for the brake pin won’t line up.



f) Position the brake spring – one end has a bent end that must go in the larger recess in the caliper body. Insert the brake pin, lining up the holes in the brake pad tabs and the loops in the brake pin spring. When lined up, the spring ball on the end of the pin should be fully recessed in the caliper body.

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g) Using new copper washers, one on each side of the brake hose metal end, reattach the brake hose to the bottom of the caliper with the banjo bolt.

h) Reinstall the brake hose bracket bolt and torque to 38 ft-lbs (51 N-m).

i) Torque banjo bolt to 132 in-lbs (15 N-m).
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9. Brake cable

a) Push the brake cable sheath through the hole in the caliper body.

b) Grab the ball end of the cable and hook it onto the brake arm.
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10. Bleed Brakes

a) Make sure the brake reservoir is full. Install the cap or brake fluid will squirt out during bleeding. Periodically check the fluid level during bleeding so the reservoir does not run dry.

b) Get some help to bleed brakes – push down on the pedal, open bleeder, close bleeder, release pedal. Do not release the pedal with the brake bleeder open.

c) Halfway through the bleeding, violently kick the brake pedal several times. Then keep your thumb on the parking brake handle and yank it up and down several times. This will help ensure that air bubbles that might otherwise be trapped on the internal parking brake self-adjusting mechanism are loosened.

d) Finish bleeding and cover bleeder screw.
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11. Put the wheel back on and tighten lug nuts in proper sequence to 90 ft-lbs (122 N-m).

12. Repeat on the other side.

13. Before driving, fully depress brake pedal to ensure pads are close to contacting the rotor.

14. Follow break-in procedure for new brake pads if new pads are installed.



The procedure should take roughly 1.5 hours if you’ve never done it before. The biggest “hints” were already mentioned- using pliers to remove and install the brake cable and exercising the parking brake during bleeding to loosen any bubbles.


Any comments or corrections are welcome.

 

[Viper Wizard]

O shoot, I've been installing them on the front? Is that why I can hear my customers scream on the first corner past my shop?

Just kidding!


Thanks Tom, perfect!

 

[cyaford]

This makes me think I may be able to pull this off without needing "help".

How does the exchange work? Would you need my calipers prior to ordering or after installation of the 40mm calipers? Do you have a preference to brake pads? I had switched over to EBC greens from stock, but still do not feel confident when having to brake hard. Stop wise, I feel the EBC greens are better than stock, but the stopping power is still lacking, IMO. I was thinking of getting your 40mm calipers, EBC red pads, and EBC sport rotors. Surely the car will brake much better after all of that.

 

[plumcrazy]

great post tom, thank you

 

[Tom F&L GoR]

This makes me think I may be able to pull this off without needing "help".

How does the exchange work? Would you need my calipers prior to ordering or after installation of the 40mm calipers? Do you have a preference to brake pads? I had switched over to EBC greens from stock, but still do not feel confident when having to brake hard. Stop wise, I feel the EBC greens are better than stock, but the stopping power is still lacking, IMO. I was thinking of getting your 40mm calipers, EBC red pads, and EBC sport rotors. Surely the car will brake much better after all of that.

Changing calipers is not physically difficult or mechanically complicated. How it works:

If you sound familiar (meaning that I see you post here) I only need your address. I ship you the brakes with a self-addressed envelope for you to mail me a check upon receipt. (Chuck Tator payment method.) Then I ask that you swap and return your old calipers within a month. (Save the USPS mailing box and shipping cores back costs $9.) This lets you schedule the work and minimize your Viper's downtime. Unless you purchase the calipers outright (see my post in the supplier section) I need the cores returned and in a timely manner to make 40mm brakes for the next guy.

I tried the original EBC greens and did not like them - had to press sooner and harder on the pedal. From what I have read it sounds like the newer Greens are different. I personally like OEM pads for mostly normal driving and Brakeman#3 pads for normal to autocross to track use. Only from reading the literature, EBC Reds and B#3 seem very similar.

Unless you are trying to reduce unsprung weight, I do not see a significant performance benefit in changing rotors. The pad material is the overriding factor (as you discovered with your own pad change). B#3 pads will grip "faster", harder with a linear pedal feel, and in my experience, have never faded. I have to point out that I have a brake fluid recirculation valve system (push pedal to pump brake fluid into calipers, release pedal ***** fluid back to master cylinder via secondary brake line system.) This NASCAR trick seems to have eliminated all my brake fluid boiling issues. Even so, if you are overheating the calipers (boiling fluid), I don't see changing rotors as a cure.

 

[ELW98]

TOM you have a PM.