SECTION 10
ENGINE MOUNT, WHEELS, BRAKES AND FAIRINGS
RV-8/8A
10-1
8-s10r9 7/11/11
ENGINE MOUNT
The RV-8/8A engine/nose gear mount is shown on DWG 49.
The mount is fitted by squaring it with the firewall of the fuselage and aligning it with the pre-drilled holes in the
corners of the firewall. Variations in the dimensions of the mount should be small enough that they can be
compensated for by the differences between the undersize holes in the firewall and the 3/8'' full size holes in the
mount. The two center holes in the –8A mount are also drilled at this time. Spacers can be used between these
two attachment points and the firewall if necessary
Drill the holes in the firewall to full size using the engine mount as a guide.
INSTALLING THE RV-8 MAIN GEAR AXLES AND BRAKE ASSEMBLIES
The main landing gear legs and the tail wheel were installed during the construction of the fuselage. Now it is time
to mount the axles, install the tires, tubes, brake assemblies and the landing gear fairings.
Put the fuselage up on sawhorses so the bottom of the main gear legs are about 12” off the floor. Level it, both
span wise and lengthwise, using the cockpit rails as a reference. Secure the fuselage and the sawhorses in this
position. They will stay here for some time, while the wheel assemblies, wheel fairings and gear leg fairings are
fitted.
Use plumb bobs and a chalk line to establish the lengthwise centerline of the fuselage on the floor. Use an
indelible marker to replace the chalk line -- it will be the reference line for much of the upcoming work, and chalk will
not last long enough.
Bolt the N5:00x5 axles to the gear legs as shown on DWG 45 using hardware store nuts and bolts.
The gear legs were aligned during fuselage construction, so the axles should be very close to the desired position,
with maximum 1/4
q
toe-in or toe-out. Check this by running a taut monofilament line from 1/2” thick spacers placed
on the forward surface of the axles as shown on DWG 45. If the axles are not aligned they may be shimmed.
Tapered shims that install between the axle and the gear leg are available through Van’s Accessories Catalog (
q
shim, p/n U-811A, or 1/2
q
shim, p/n U-811B).
Cleveland brakes are included in the kit. Swap the fittings on one brake assembly to make a left and right brake.
Remove and store the inside brake pad.
Deburr and prepare the U-807 Wheel Fairing Attach Bracket.
Remove the temporary bolts attaching the axles, and mark the position of any shims, so they can be reinstalled
correctly.
Install the axles, brake assemblies and U-807 brackets as shown on DWG 45. The exact orientation of the brake
assembly is important -- it must be as shown to fit inside the fairings.
Fit the 5:00x5 Cleveland wheels and U-405 Axle Spacers (one on each side of the wheel) on the axle. Install the
VA-106 wheel nut. Tighten this nut carefully, until there is no side play in the wheel, but it still rotates smoothly.
The nut is secured by a large cotter pin. Use the holes in the nuts as a guide and drill holes in each side of the
axles. If you misalign these holes slightly, it is permissible to elongate the holes in the nut, parallel to the axles,
until the cotter pin will fit.
Install the cotter pin that secures the wheel nut.
INSTALLING THE RV-8A MAIN GEAR LEGS, WHEELS AND BRAKES
The main landing gear legs are installed as shown on DWG 30A. This was probably done during construction of
the fuselage.
The axle and U-403 Brake Mounting Flange on the RV-8A gear legs have been designed to use the Cleveland
SECTION 10 : ENGINE MOUNT, WHEELS,
BRAKES AND FAIRINGS
RV-8/8A
SECTION 10
ENGINE MOUNT, WHEELS, BRAKES AND FAIRINGS
10-2
8-s10r9 7/11/11
5:00x5 wheel and brake assemblies. The brake mounting flange has been honed and drilled to fit the axle at the
factory. See DWG C2, Sect. A-A’. The hole through one side of the U-403 is still undersize, so, before final
installation, pass a 5/16” drill through the assembly. Now install the Allen head screw that secures the brake flange
to the axle. It is possible that the heat treating process used to strengthen the gear leg has expanded the axle
slightly, and the flange will not slip on smoothly. A strip of fine crocus cloth briskly worked around the axle will
remove the black scale and allow the flange to be installed.
Each brake has a mounting plate supplied, which bolts to the U-403. Three of these bolts, running through U-408
spacers, also attach the U-810 Wheel Fairing Mount. The exact length of these spacers may be altered slightly to
achieve the correct gap between U-810 and the brake disc. See DWG C2, Sect. A-A’.
Mount the U-810, U-408 spacers and Cleveland mounting flange to the U-403 brake mounting flange as shown on
DWG C2. Install the AN822 brake line elbow in the Cleveland brake assembly. Remove the inboard brake shoe
from the brake caliper, and bolt the caliper to the mounting flange. Brakes are mounted with the caliper aft of the
axle, and the bleed nipple down.
Fit the 5:00x5 Cleveland wheels and U-405 Axle Spacers (one on each side of the wheel) on the axle. Install the
VA-106 wheel nut. Tighten this nut carefully, until there is no side play in the wheel, but it still rotates smoothly.
Then, through the cotter pin hole in the nut, center punch mark the position of the cotter pin hole in the axle.
Remove the nut and wheel, and drill a 1/8’’ hole in the axle for the cotter pin.
MAIN WHEELS and TIRES
Split the wheels by removing the bolts holding the wheel halves together.
Remove and inspect the wheel bearings. This requires removing the circlip retainer and popping the tapered
bearing assemblies out. Be sure they are fully greased with Aeroshell #5 or equivalent.
Re-install the bearings and mount the tubes and tires on the wheels. Dust the inside of the tire with talcum powder
before installing the tube. Discard the nuts and washer on the valve stem. The red dot on the tire should be
installed next to the valve stem of the tube.
Bolt the wheel halves together. Carefully observe the manufacturer’s bolt torque specifications, shown on the
document in the wheel/brake package.
SLOWLY inflate the tire to 25 psi. Deflate it fully and re-inflate it SLOWLY a couple more times to work out any
wrinkles in the tube. Inspect for a good seat around the wheel rim.
Install the wheel and re-install the inside brake shoe with bolts and safety wire.
BRAKE LINES
Exterior brake lines are fabricated and routed as shown on DWG 45 (RV-8) or DWG C2 (RV-8A). Remember to
install the fittings on the aluminum lines
before
making the flare.
Brake lines are run down the trailing edge of the gear leg. Every 12-14 inches, protect the brake line with a short
section of plastic tubing that has been slit and wrapped around the line. Tape the brake line to the gear leg with
reinforced packaging tape.
Install the F-8103 Release Mechanism and F-8102 Release cable on the adjustable rudder pedal assembly. See
DWG 46.
Interior brake lines, master cylinders and hoses are installed as shown on DWG 34. Begin by bolting the master
cylinders to the bottom lug on Wd-816. Then bolt the Wd-820 brake pedals to the rudder pedals. Detail F shows
how to modify the rudder pedals if necessary so the brake pedals will fit. Align the brake pedals, setting them so
they both rest at the same angle, and locate the hole for the top of the master cylinder -- see Detail E.
Once this hole is drilled, the master cylinders are attached to the brake pedals as shown in Detail D.
Make two F-866D Mounting Plates, drilling them in assembly so the holes match exactly. One of these will be
trimmed to become the shim shown in Section B-B, the other is the actual F-866D that rivets to the F-866APP
bulkhead. When this plate and doubler is installed, the high-pressure lines from the master cylinder are routed and
installed. Be sure to install them in the proper port on the master cylinder! Section B-B shows details and fittings.
Install the VA-107 brake fluid reservoir as shown on View C-C.
Install the low-pressure plastic lines between the brake fluid reservoir and the master cylinders. Note routing and
clamping details shown in the various views. Details of installing fittings on the plastic lines are shown on the lower
left of DWG 34.
