Front Calipers
Click through the pictures to view the calipers during disassembly, sandblasting, and powder coating.
- Picture 1: Taped for glass bead blasting
- Picture 2: Before and after blasting
- Picture 3: Before and after wire wheel
- Picture 4: Masked for powder
- Picture 5: Finished
I used flat clear and really liked the way they looked. Too bad they rusted.
I read that stainless steel cylinder sleeves are not supposed to be honed. However, these had a wear ring, and I figured it couldn't make them worse. I set the honer tension so the stones were snug against the cylinder, but not tight. Using cutting oil, I honed for 30 second intervals until the wear ring was gone. I cleaned the cylinders with brake cleaner afterwards and lightly coated them with brake fluid. I hope I won't be replacing my calipers.
I cleaned the piston and springs with brake cleaner and inspected them. I found minor pitting in non-critical areas and smoothed them with fine sandpaper. You can see there is some wear, but they are serviceable.
During lip seal installation, I used a small flat tip to press against the base of the seal and seat it properly in the piston. Compare the lip angles in each picture and to see what I mean.
NOTE: To facilitate photos, I did not have the spring installed in the first four pictures of the series to the right.
Inserting pistons into a cylinder takes a little patience because the spring pushes them out. I pressed the piston by hand until the seal contacted the cylinder rim. Then, applying light pressure to the piston, I tucked the lip seal into the cylinder using a small flat tip screw driver (second picture). A properly installed lip seal should look like picture three. Ensure the dust seal metal ring is seated evenly (fourth picture), otherwise it will deform when pressed in and could be ruined.
Caliper assembly is straight forward. The half containing o-ring seats also contains bolt threads, and it's easiest putting this on the bottom during assembly. Before assembly, I chased the threads so the torques would be accurate. The torque on these babies is 135 ft-lbs.
I chose stainless steel, one man bleeder screws. I don't know how well they work, but got them because I am tired of using vise-grips to loosen bleeders. These have a rubber cover and hopefully between that and the stainless material, I won't have to grinding flats in bleeders again.
SUMMARY: That completes this portion of the brake project. I'd rate this job as a 4. Take your time installing the lip seals and lining up the dust seal ring and you won't have any problems.
I won't be posting a walk through for the rear calipers, as they are nearly identical. The only differences are an extra bleeder screw and the bolts are torqued to 85 ft-lbs because the calipers are smaller.
This task will be completed in phases. I rebuilt the front calipers while doing the front suspension, and the rear calipers with the rear suspension. The master cylinder will get done with the firewall, and the lines got installed prior to mating body and frame. So this task intertwines with several others. Before tackling the brakes, I needed to make some decisions.
BRAKE PADS: I'm still researching, but Hawk brand gets good reviews. They have a variety of compounds, and I'm interested in their HP pad for auto cross applications. This compound allegedly alleviates brake fade and could nicely compliment the blank rotors I'm using.
BRAKE PAD SHIMS: Many Stingray owners, including myself, can testify to the annoying squeak coming from the calipers during slow cruising. This is caused by the pads rubbing against the pistons as they rock back and forth on the retaining pin, and corrected using shims that on the ends of the pads. I'm definitely installing those.
BRAKE ROTORS: There wasn't much to research here. I intended to use the existing rotors because I installed new trailing arms from Ikerds in 2011. These had OEM rotors riveted on, and only 15,000 miles on them, if that. Once I discovered new front rotors were required, I went with blanks. This was unplanned cost I wanted to minimize.
O-RING SEAL KIT: These kits convert the old lip seal design to an o-ring design. The o-ring set up has two advantages: it maintains integrity over longer periods of inactivity, and is more tolerant of rotor run-out. The disadvantage is the conversion requires new caliper pistons and costs $50 a pair, where lip seal kits can be had for about $19 a pair. O-rings are a great option for cars driven seldom, but do not improve braking. And while o-ring kits are tolerant of run-out, run-out itself is undesirable as it can cause significant pedal and steering wheel vibration. As discussed in the Spindle and Rotor walk through, my new rotors had significant run-out when mated with the hub, and pedal / steering vibration was a real concern. Since that needed correction, I saw no reason to spend the extra money on the o-ring conversion.
HYDRO-BOOST: For those that don't know, hydro-boost uses power steering hydraulic pressure instead of manifold vacuum for brake assist. A new, bolt-in hydro-boost system is more than $1,000. It's possible to put one together from 3/4 ton GM pick-up components (and probably other vehicles as well), though a firewall mount plate must be fabricated. Hydro-boost is primarily useful with long duration camshafts (and hence low manifold vacuum), or for those who don't like the vacuum system's feel. Hydro-boost assisted brakes require less effort, but braking power remains the same. It could be argued that hydro-boost decreases stopping distance by engaging the brakes earlier, but I suspect the difference is insignificant at cruising speeds. To me, it's a lot of expense for little gain to my application. I'm staying with the stock system, but will replace the vacuum booster because they fatigue with use.
BRAKE LINES: Just a short word here, but I plan to upgrade to stainless lines. They are harder to seat but help prevent brake fluid contamination due by eliminating rust in the lines. UPDATE: I replaced all my brake lines a couple years before and decided to reuse them since they were in very good shape and will likely last longer than I will.
CALIPER PAINT: I decided to use powder coat on the calipers because of its superior durability. I wanted a stock look so I went with flat clear. UPDATE: It has been almost a year since I finished rebuilding the calipers and I'm sorry to report that surface rust has started to appear on them. I admit to being a novice at powder coating, so I likely did something wrong. I suspect that the porous nature of the cast iron requires a second coat and/or longer preheat than I did. I'll change these on the rear calipers and post an update if it makes a difference.
Modifications: None
Upgrades: Three
- Brake pad vibration dampers
- Hawk HP auto-cross semi-metallic pads
- Stainless steel brake lines (DID NOT INSTALL THIS UPGRADE)
Brakes