With 230 hours and about 350 landings on my RV-8, the Valkyrie, I decided that I had put enough wear on the outside of the tires, and it was time to start working on the other half of the tread! My tires are retreaded AirHawk's from Desser (I've been using these on my airplanes for over 20 years, and getting good service!), and I installed this pair at about 50 hours total airframe time. Seeing as how the wear on the outside was nice and even, I expect to get the same wear on the inside (which is now the outside...), for an expected lifetime of about 360 hours. I'm also using the Michelin Air Stop tubes, and only have to add about 1 psi every two or three months.
Since it was raining hard this morning, I figure this was a good chance to do the work. I removed both wheel pants, and noted no wear (I was wondering if I would see any rubbing from the brake assemblies, as many people have had interference that required them to install a blister),so I guess I was lucky with my fit. Jacking up one side at a time, I split the rims, removed the tubes, and reinstalled the tires reversed on the rims. A very tiny touch of dish soap makes it much easier to feed the valve stem through the grommet in the wheel!
My brake pads looked fairly thin, and I must admit that I embarrassed myself a bit as a result. Based on my experience with my old Grumman brakes, these pads looked gone - the surfaces were almost down to the rivets! I checked with my neighboring A&P to see if he had any, but he was fresh out. Fortunately, we have a Pilot's shop at nearby Ellington Field, so I drove over there to get two sets - but when I looked at the new ones, I was red-faced to see that they were almost the same thickness as my "used ones". I guess I never really inspected them when I installed the wheels and tires on the airplane - the new metallic pads are much thinner to start with than the older pads. Of course, if I had the Cleveland documentation at the hangar, I could have done it the right way, and measured them versus spec....Anyway - no new pads, the old ones were fine!
One thing I did notice about the brakes was that my right side pads were slightly thinner than the left, so I guess I use more brake on that side. I reinstalled them on opposite sides of the plane, to get them to wear evenly. After re-installation, I pumped a little fluid into both sides (from the bottom, with a converted oil can) to make sure the lines were bled.
I figured that since the plane was in the air, this was a good time to check the gear leg torque - and onerous job on an -8, and one which needs to be done occasionally. As I have found on previous checks, the torque was fine, and I might just stop worrying about it. Of course, since I had the wheels apart, it was also time to grease the wheel bearings - they were in great shape, but just a bit dry. I probably didn't get them quite full enough on the initial packing, trying to keep things neat.
Overall, I was very pleased with what I found down below - no uneven wear and tear at all. I set mine up during the build exactly as th plans said - zero toe-in or out. Control is good on the ground, with no darting on touchdown. I am running 35 psi in the tires, and when they get down to 32 or so, my wheel pants drag on the hangar door tracks when I pull the plane out - my little tire pressure indicator!
With my Condition Inspection due in October (my, how time flies!), I'm pretty satisfied that the undercarriage will be just fine.
Paul
Since it was raining hard this morning, I figure this was a good chance to do the work. I removed both wheel pants, and noted no wear (I was wondering if I would see any rubbing from the brake assemblies, as many people have had interference that required them to install a blister),so I guess I was lucky with my fit. Jacking up one side at a time, I split the rims, removed the tubes, and reinstalled the tires reversed on the rims. A very tiny touch of dish soap makes it much easier to feed the valve stem through the grommet in the wheel!
My brake pads looked fairly thin, and I must admit that I embarrassed myself a bit as a result. Based on my experience with my old Grumman brakes, these pads looked gone - the surfaces were almost down to the rivets! I checked with my neighboring A&P to see if he had any, but he was fresh out. Fortunately, we have a Pilot's shop at nearby Ellington Field, so I drove over there to get two sets - but when I looked at the new ones, I was red-faced to see that they were almost the same thickness as my "used ones". I guess I never really inspected them when I installed the wheels and tires on the airplane - the new metallic pads are much thinner to start with than the older pads. Of course, if I had the Cleveland documentation at the hangar, I could have done it the right way, and measured them versus spec....Anyway - no new pads, the old ones were fine!
One thing I did notice about the brakes was that my right side pads were slightly thinner than the left, so I guess I use more brake on that side. I reinstalled them on opposite sides of the plane, to get them to wear evenly. After re-installation, I pumped a little fluid into both sides (from the bottom, with a converted oil can) to make sure the lines were bled.
I figured that since the plane was in the air, this was a good time to check the gear leg torque - and onerous job on an -8, and one which needs to be done occasionally. As I have found on previous checks, the torque was fine, and I might just stop worrying about it. Of course, since I had the wheels apart, it was also time to grease the wheel bearings - they were in great shape, but just a bit dry. I probably didn't get them quite full enough on the initial packing, trying to keep things neat.
Overall, I was very pleased with what I found down below - no uneven wear and tear at all. I set mine up during the build exactly as th plans said - zero toe-in or out. Control is good on the ground, with no darting on touchdown. I am running 35 psi in the tires, and when they get down to 32 or so, my wheel pants drag on the hangar door tracks when I pull the plane out - my little tire pressure indicator!
With my Condition Inspection due in October (my, how time flies!), I'm pretty satisfied that the undercarriage will be just fine.
Paul
