We've received a request for a
“HOW TO” on replacing brake linings. Although not an approved task for owners
under the preventive maintenance provision of Part 43, the task is fairly
simple but will require a sign off by an A&P.
1. Flat blade screwdriver
2. Diagonal side cutters
3. 1/4" combination wrench
4. 7/16" combo wrench or socket and ratchet.
5. Pin punch and small shop hammer
6. Brake lining rivet tool
7. Brake Linings
9. 5606 Brake fluid
oz pistol grip oil can
1/4" clear vinyl tubing
5/32 Cleco and pliers
Work bench and vise
16. .032 safety wire and pliers
Before 1967, our Mooney’s used Cleveland brake
assembly part # 30-5. This assembly used
a three hole lining current part # 066-11100.
After 1967 and for a few of
the 1966 Executive models, Mooney switched to the Cleveland assembly # 30-56.
This assembly used a two hole lining current part # 066-10500. (Fig 2) Both
assemblies use rivets part # 105-00200.
It is not necessary to jack up
the aircraft or remove a wheel to replace the linings. Fig
3.For the removal process refer to fig 8 and fig 9.
1. First I remove the safety wire, if installed, on the two 1/4" bolts(1) that attach the brake cylinder (5) to the back plate(15).
2. Next I place the blade of a screwdriver between the pressure plate (12) and the
brake disc. Fig 4 Prying the pressure plate towards
the brake cylinder will move the piston inward and allow clearance for the
installation of the new linings.
3. Remove the two bolts (1) and remove the pressure plate (15).
brake cylinder can now be removed from the torque plate(18)by sliding outward.
5. Remove the pressure plate by sliding it off of the anchor bolts (17).
6. Place “C” clamp over piston and brake cylinder to keep piston from coming out of cylinder.
7. Take the pressure plate and back plate to your work bench. Using
the punch and hammer, remove the rivets holding the old linings.
You can also use a drill but with caution. Too large a bit and the hole in the plates can be drilled oversize
and cause replacement of the
plates. These items are very
8. Clean oil and residue from plates.
9. Place the rivet tool in a vise. I prefer to use the screw type tool. Using the hammer type
tool can damage the three hole 066-11100
lining which is very thin.
use a 5/32 Cleco to secure the lining to the pressure
plate. Insert a rivet and squeeze. Fig. 5Remove the Cleco
and install the remaining rivets in both plates. Fig. 6
11. Returning to the plane, inspect the anchor bolts(17) for rust, wear and nicks. Polish with fine emery
or scotch Brite pad. Check bore of torque plate(18) and clean as necessary. The anchor bolts must
slide freely in the torque plate.
12. Remove “C” clamp and install pressure plate over anchor bolts.
13. Install brake cylinder by inserting anchor bolts into torque plate.
14. Install back plate on brake cylinder using the two 1/4" bolts and
torque to 90 inch pounds. Check to see that the assembly
is loose and floating
in the torque plate. Safety wire bolts together using .032 safety wire.
Install a length of clear vinyl tubing to the vent on the hydraulic reservoir
and the other end in the small coffee can. Fig7
Fill the oil can with 5606 aircraft brake fluid. Automotive fluid will NOT
work. Attach a small length of the clear vinyl tubing to the oil can by sliding
it over the stem. Fig 8 Pump the can until the tubing is full of fluid with no
17. At the bottom of the brake cylinder is a bleeder valve(7). Loosen
the bleeder with the 1/4" wrench one full turn. Attach the loose end of the oil
can tubing over the bleeder valve. Pump about one half the contents of the oil
can thru the brake system being careful not to allow bubbles to enter the clear
tubing. Remove the tubing and tighten the bleeder valve.
18. Repeat procedure for opposite side and remove tubing from brake reservoir.
19. Check reservoir for proper fluid level and adjust as necessary.
Check brake operation before starting engine. There may be a low brake pedal on
the first application.
Later models aircraft with
inner gear doors will require the loosening of the inner gear doors but not
removal. Some model have a single bolt at the center
axle and a brace at the forward gear leg. Others have two bolts at the axle
center that are safety wired together. Removing these center bolts will allow
the gear door to move away from the brake cylinder. Be aware that each of these
bolts have washers as spacers between the axle and
gear door. These must be replaced as installed to provide clearance between the
gear door and the tire.
Dual Puck Brakes
Dual puck brakes are installed
or are optional on the “K” model and up to the current models. These brakes are
constructed like two of the single puck units molded as one unit. They use the
same 066-105 lining just twice as many per side. Relining is done in the same
manner as the single puck units.