Heavy duty brakes - Performance differences? Worth it?

[mshac]

Just found out my 1978 P337H has the "heavy duty" wheels & brakes option vs "standard" wheels & brakes.

Both options are rated for the same max weight, but the HD option does include metallic linings, and mains are larger tires, and run at higher PSI (70).

The HD tires are over $400 each, and are the same as used on the Lear 25 bizjet series.

Other than using an oddball tire and wheel size, what makes the HD option worth the extra money?

Does it shorten stopping distances?

Does it increase brake life?

Since HD wheels & brakes were sold as an option, all it takes to switch to "standard" wheels & brakes is to switch them out with the proper parts, and change the tire inflation placard on the upper entry door.

Anyone with an opinion based on experience, I'm listening...

[JimC]

Originally Posted by mshac

Since HD wheels & brakes were sold as an option, all it takes to switch to "standard" wheels & brakes is to switch them out with the proper parts, and change the tire inflation placard on the upper entry door.

I looked into this. All the parts are sold as a kit. Yes, you have to swap basically everything from the gear leg outboard. The light duty tires are wider and run at a lower pressure, so you may find an advantage if you're off pavement.

[mshac]

Originally Posted by JimC

The light duty tires are wider and run at a lower pressure, so you may find an advantage if you're off pavement.

I operate from a grass strip, so this could be a selling point for me!

One thing I like about the HD brakes is the ease of service. Remove a few bolts, pull off the caliper, pop off the old linings, and the new metallic linings "click" into place. No messing around with rivets. I just bought a box of 10 Cleveland 066-02200 pads for $100, so I should be set for years to come.

[mshac]

Cessna wants something like $85 for the "shim" required on HD brakes. Its a joke of a price! Rapco has some for $60, but still crazy.

FYI if you find yourself in need of a new shim or two, you can make your own from 1mm or .04" high temp gasket material. A lifetime supply is $15 at Autozone. You could make 50 shims out of the sheet you get!

The shim in the second photo is the factory shim. It was so brittle, it snapped in two when I was removing it. The other wheel didn't even have a shim, but when I put the new pads on, the brakes were grabbing. The shim is required for proper functionality! They say its to impede heat from transferring, and that may be true, but the new pads don't have enough clearance from the rotor without the shims. Of course the old worn pads did. But they were about to start causing rotor damage, it was time for replacements.

I scanned the original shim to pdf, and attached it for all to use. Print it to 8.5" x 11" paper and the size should be perfect.