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9A BRAKE PAD REPLACEMENT

mmckissock

I'm New Here
HELLO EVERYONE,
IM NEW TO THE FORUM AS I JUST BOUGHT A RV 9A. T LOOKS LIKE I NEED TO REPLACE BRAKE PADS. CAN ANYONE GIVE ME SOME INSIGHT?
I HAVE REPLACED BRAKES ON MY PREVIOSLY OWNED RANS COYOTE BUT THIS IS MY FIRST GO AT THE 9A.
ANY INSTRUCTIONS OR VIDEOS AVALABLE?
THANKS
 
Pad replacement.

Very easy. You first need this tool.

https://www.aircraftspruce.com/catalog/topages/brakeliningrivset.php?clickkey=10979

Remove the two bolts (7/16” hex head) that are wire tied from the inboard caliper.
The outboard pad will drop to the floor. Slide the inboard caliper towards the center of the plane until it dislodges from the two studs. You can then remove the inboard pad. Use the tool above to remove and replace the pads. The wheel does not have to be jacked up.
 
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I'm still a big fan of OJT (on the job training), if you've never done a job before then it's smart to have someone show you how to do it first so you don't unwittingly mess something up.
 
Thanks for the insight guys. Didn't catch the brake wear in the pre buy inspection so shame on me. I've got about 10 hrs in the plane and started hearing the brake issue. I think im into the rivets but not sure.
 
I would just put new o rings on the caliper pucks also. Cheap and can save you being stuck at an airport.
 
If you replace the rotors, be sure to deflate the tire before loosening the bolts. It’s a split rim and it will get ugly if you don’t. Also note if you open the hydraulic system to change the o-rings you have to bleed the air out. I agreee with the poster above that getting help the first time is a good deal
 
I would just put new o rings on the caliper pucks also. Cheap and can save you being stuck at an airport.

Changing the O rings is a much bigger job than the pads. You will need to have a setup to bleed the system. Also one can easily put them together wrong. I would leave them alone unless they are leaking.
 
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std o-ring MS28775-218
most common fluid Royco 782 but you should check what the builder used.

If you haven't serviced this style brake system (or any) before, I suggest you find someone who is experienced doing this to mentor you. If not done properly, a lot of things can go wrong.
 
Sorry, to clarify earlier post

"Anybody have a number for the o-rings?"

std o-ring MS28775-218



"ONE MORE QUEDTION....WHAT BRAKE FLUID SHOULD I BE USING WITH THE CLEVELAND 5.00 X 5 CALIPERS?"

most common fluid Royco 782 but you should check what the builder used.
 
Buy two, maybe three extra pads when you order. Good chance you'll break one or two riveting them. Especially if you've never done it. And I wouldn't touch the o-rings unless you suspect a problem, or they're over 10 years old. 5 if you routinely brake hard/heat up the brakes.
 
yes, by all means, buy extra pads. You will use them sooner or later.

MIL 5606 brake fluid is more commonly found in my experience and is fine, although the ROYCO stuff has a little better flammability characteristics. ROYCO and 5606 can be mixed without worry, but this is not always the case with other fluids that are sometimes used, so best to know what is currently in use.

erich
 
Brake Maintenance

In early September, I Discovered the importance of two working brakes in a RV9A. I taxied up to the hold short line, stepped on the brakes and started doing left donuts.
The O-Ring had overheated and assumed a square section, thus dribbling red.
This is my upgrade installation, first brake job, based mostly on this forum in bits and pieces and the Cleveland publications.
I hope others find it helpful.

The Discs:
-The Cleveland upgrade kit is a Cleveland upgrade Kit 199-93 contains every thing you need (I Think) for $ 674 from ACS.
-The Van’s Original Replacement Cleveland disc is a 164-01700 $169 from ACS. The Disc is 0.182” thick new and fails at 0.167” min.
-The upgrade Rapco disc is a 164-09900 $98.50 from ACS. The Disc is 0.295” thick new and fails at 0.275” min.
-The difference between the Cleveland disc and the Rapco disc is 0.295- 0.182= 0.113 ~= to 0.125 for the shim.

The Brake Assembly
-Matco Brake liners are 0.186 thick new and 0.100 thick min.
-Use Dow Corning #55 o-ring lube for the piston o-ring.
-Use locktite C5A anti seize for the anchor bolts.
-Use Arbor Shim 0.0620 x 1.25 ID x 1.750 OD PN# 5GA99 from Grainger
-Use Bleeder valve cap PN# 183 00100 from ACS
-O-Ring MS28775-218 $0.49/ea from ACS

INFO
-Parker Hannifin Corp.
1-800-272-7537
-Cleveland Wheel and Brake Product catalog
Pub Number AWBPC0001-20/USA


Tools Used
-Brake Fluid Reservoir vent. 7/16” Wrench.
-My brake fluid drain tube with AN fittings 1/2” & 9/16” Wrenchs.
-Brake assembly Bleed Fitting 1/4” 6 Point box end combination Wrench. Use the six Point end only to tighten and break loose the Bleed fitting. It is tiny.
-VA-106 Axle Nut. 1 1/2” Socket.
Backplate Bolts 7/16” Wrench.

The Procedure
-Remove the brake Assembly and one Wheel using your preferred jacking method.
-Let the air out of the tire.
-I used for wooden stakes and four bar clamps to hold the wheel assembly together, while removing the three bolts holding the wheel and disc together. Replace the disc with the new disc.
-Lube the Axle and install arbor shims and slide the wheel back on. Vans wants 0.032 to 0.094” gap between the disc and U-810 (The inside Main Wheel Fairing support plate). Add or remove shims to achieve the gap.
-Reinstall the Axle Nut and adjust by sanding the inside end to allow the Cotter key to be reinserted.
-Make two 1/8” Al spacer to the shape of the machined surface on the Back Plate.
-Lube the o-ring, piston and cyl with the o-ring lube.
-Lube the Anchor bolts and the anchor bolt holes with the anti seize.
-Use a 3/16” dowel to insert through the top bolt hole, the shim and the back plate. This will hold that assembly in place while starting the lower bolt into the backing plate. The top bolt is then easy to install.
-Bolt torque for Backplates 75-80 inch-lbs.

Matco Master cylinders are MC-4-F Left (2 needed) and MC-4-F Right (2 needed).
 
Matco

Just to add more information here, Matco provides a FREE service of replacing the pads for u when u send in your worn pads. They charge only for the cost of replacing the pad itself. No need for the Rivet tool and possibly braking them accidentally. $30-$35 or so. Have used it each annual to have a fresh set on the shelf, so no down time.
 
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