Al Downs Posted June 19, 2015 Report Share Posted June 19, 2015 Anyone had experience with replacing a landing leg? Students finally broke the right main. Hopefully when I call tomorrow I can get one soon. Big Job?? Link to comment Share on other sites More sharing options...
Tom Baker Posted June 19, 2015 Report Share Posted June 19, 2015 Not a big job. It is about a hour or two job on the LS, and a little more on the SW. IIRC you don't even have to bleed the brakes on the LS. The one thing I did find on the LS was the airplane didn't set straight with the new gear. I guess the old gear had plenty of time to settle. Link to comment Share on other sites More sharing options...
Madhatter Posted June 19, 2015 Report Share Posted June 19, 2015 Big job on the sw, only the middle hole is drilled on the new gear leg. You have to be very precise in drilling the other two as the knuckles and upper tubes are already drilled. Toe-in is difficult to get right. All this takes a lot of thinking and you only have one shot at it. If you mess up the hole alignment there is no fixing it. I used a hole drilling jig to stay centered and a lot of alignment checks. There is only a very small negative toe-in. If you have Matco wheels you have some adjustment for toe- in but not the Italian wheels Link to comment Share on other sites More sharing options...
Al Downs Posted June 19, 2015 Author Report Share Posted June 19, 2015 I should have mentioned I have a LS. Hoping it is easier. Link to comment Share on other sites More sharing options...
Anticept Posted June 19, 2015 Report Share Posted June 19, 2015 I just found a cracked gearleg a few hours ago on one of ours during the inspection. Just take off the caliper, and remove the 4 bolts that hold the gearleg in. Reverse procedure (torque to MM spec) and you're done. You need to check for other damage too. If the gearleg is semi broke, you should be fine, but if it's broke broke, you need to check the tail, wing attach points, and nose, engine mount, and other main. EDIT: And align the wheels. Have to do that part! Link to comment Share on other sites More sharing options...
FlyingMonkey Posted June 19, 2015 Report Share Posted June 19, 2015 Big job on the sw, only the middle hole is drilled on the new gear leg. You have to be very precise in drilling the other two as the knuckles and upper tubes are already drilled. Toe-in is difficult to get right. All this takes a lot of thinking and you only have one shot at it. If you mess up the hole alignment there is no fixing it. I used a hole drilling jig to stay centered and a lot of alignment checks. There is only a very small negative toe-in. If you have Matco wheels you have some adjustment for toe- in but not the Italian wheels I find the toe in on the SW to be problematic, inconsistent, and leads to tire wear. If I was replacing gear legs I'd be very tempted to minimize or eliminate it from the setup. Link to comment Share on other sites More sharing options...
Al Downs Posted June 19, 2015 Author Report Share Posted June 19, 2015 Thanks to everyone for your help. Leg is ordered and will be here Monday. Link to comment Share on other sites More sharing options...
Tom Baker Posted June 19, 2015 Report Share Posted June 19, 2015 Big job on the sw, only the middle hole is drilled on the new gear leg. You have to be very precise in drilling the other two as the knuckles and upper tubes are already drilled. Toe-in is difficult to get right. All this takes a lot of thinking and you only have one shot at it. If you mess up the hole alignment there is no fixing it. I used a hole drilling jig to stay centered and a lot of alignment checks. There is only a very small negative toe-in. If you have Matco wheels you have some adjustment for toe- in but not the Italian wheels I have changed a gear leg on SW, and did not find it that difficult. Yes you have to drill 2 holes and set the toe. IIRC it took about 2 1/2 to 3 hours and the hardest part was bleeding the brake. Link to comment Share on other sites More sharing options...
FastEddieB Posted June 19, 2015 Report Share Posted June 19, 2015 ...and the hardest part was bleeding the brake.Harbor Freight sells a Mikwakee air powered bleeder that really makes short work of most jobs like this. Around $30, IIRC. Hooks up to a compressor and sucks the fluid through from the bleeder nipple. Link to comment Share on other sites More sharing options...
FlyingMonkey Posted June 19, 2015 Report Share Posted June 19, 2015 Harbor Freight sells a Mikwakee air powered bleeder that really makes short work of most jobs like this. Around $30, IIRC. Hooks up to a compressor and sucks the fluid through from the bleeder nipple. Bleeding has never been my problem with brakes...getting the fluid back in without air bubbles is a bigger issue. Link to comment Share on other sites More sharing options...
FastEddieB Posted June 19, 2015 Report Share Posted June 19, 2015 Bleeding has never been my problem with brakes...getting the fluid back in without air bubbles is a bigger issue. This device just sucks fluid out through the entire system, including the bubbles. It works on my BMW motorcycles, which are a bear to bleed manually. In fact, I bought the Milwaukee unit after being unable to bleed the rear brake on a bike via the conventional method. Another method is to pump fluid in through the bleeder. I've used large syringes for that before, or an oil can with a pump. Link to comment Share on other sites More sharing options...
Tom Baker Posted June 19, 2015 Report Share Posted June 19, 2015 Harbor Freight sells a Mikwakee air powered bleeder that really makes short work of most jobs like this. Around $30, IIRC. Hooks up to a compressor and sucks the fluid through from the bleeder nipple. I have a home made brake bleeder made out of a garden sprayer. It works well, and bleeding brakes is not really a problem. My comment about bleeding the brakes was directed at replacing the gear leg not being that bad. Link to comment Share on other sites More sharing options...
Runtoeat Posted June 19, 2015 Report Share Posted June 19, 2015 At this point in discussions about bleeding brakes, Roger Lee normally posts his garden sprayer bleeder. Tom beat Roger to it this time! That is on my "To Do" list. I wrestled with my CTSW's brakes the last time I bled them and will have a garden sprayer to push the fluid thru next time. I would check out Fast Eddie's system but I believe the proper method for bleeding the CT is to push the fluid thru the bleeders and then on thru the rest of the system and finally into the reservoir. This is different than the conventional (automotive) bleeding done from the reservoir down thru and out the bleeders. Link to comment Share on other sites More sharing options...
Anticept Posted June 19, 2015 Report Share Posted June 19, 2015 The tool you guys want to use is a vacuum & pressure bleeder. Here is an example: http://www.harborfreight.com/brake-bleeder-and-vacuum-pump-kit-69328.html Procedure for bleeding: IT IS IMPORTANT THAT YOU USE THE HAND BRAKE FOR THIS PROCEDURE. You may not be able to fully purge the air using the vacuum feature of the bleeder. That's for cars, aircraft master cylinders work slightly different. Open one bleeder valve and pump brake handle until reservoir is just about empty. Suggest just discarding this old fluid as it should be considered "contaminated". Attach vacuum/pressure bleeder. The one I linked, you fill the small white cylinder about halfway to 3/4, attach one nipple to the hand pump, the other to the brake nipple, and turn the cylinder upside down (nipples down). Pump hand pump until reservoir in airplane is almost full. Turn cylinder back rightside up, pump brake handle (moderate speed pulls). If you see air bubbles, go back to step 2 and do it again until you see no bubbles (no need to discard as it was clean fluid you pumped in, and a little mix with old fluid is fine as long as it's still cherry red). Leave reservoir almost full. Close valve, proceed to other brake caliper. Attach bleeder and open valve. Pump brake handle until reservoir is almost empty (discard the old fluid that was in this side's brake line), paying attention for bubbles. If bubbles are seen, perform steps 2 and 3 until none are found. When no bubbles are seen, fill reservoir to between 1/2 and 3/4 full. Close bleeder valve. Pump hand brake. It should be stiff, as though you are hitting a stop when pulling. Sponginess means there is still air, so start over. Done! Link to comment Share on other sites More sharing options...
Roger Lee Posted June 19, 2015 Report Share Posted June 19, 2015 Buy a 1 gal. pump up bug sprayer. Unscrew the tip off the sprayer and get some poly tubing to slip over the end. Then it goes over the nipple of the brake bleed, open the bleeder and press the pump handle. I put a water bottle with a piece of poly tubing taped in the neck and then slide the other end over the brake fluid reservoir to catch the over flow. I can bleed a set of CT brakes in a matter of minutes and without any mess. There is never any ai rin the systems because the pump pushes the fluid through so fast it is all pushed out. Link to comment Share on other sites More sharing options...
Tom Baker Posted June 19, 2015 Report Share Posted June 19, 2015 I use a system like Roger's. Homemade and works well. I do get some mess where the hose connects to the bleeder valve. Link to comment Share on other sites More sharing options...
Al Downs Posted June 20, 2015 Author Report Share Posted June 20, 2015 This thread went from replacing the leg to bleeding brakes but I still have one more question. I have been unable to find the torque for the bolts that hold the leg in place. Can anyone help? Link to comment Share on other sites More sharing options...
Anticept Posted June 20, 2015 Report Share Posted June 20, 2015 This thread went from replacing the leg to bleeding brakes but I still have one more question. I have been unable to find the torque for the bolts that hold the leg in place. Can anyone help? 9 newton meters. You need to use a threadlocker too. See CTLS MM Rev 4, page 4-24 and 4-25, section 4.2.2.8. I got done installing the replacement leg on one of ours, and I went ahead and pulled the other one to make sure it wasn't damaged either, and just finished when I saw your post Make sure you put in the rubber padding properly! It keeps the leg from jostling around and wearing out, and softens the impact from landing. There should be a piece glued to the bracket, and another, wider piece wrapped around the top. You can cut a piece of inner tube and use that as the pad if you need to, and 1300L to glue the rubber to the bracket and other piece to the top of the leg so it doesn't work its way out. EDIT: Thought I quoted the wrong section, changed it for a few seconds, then changed back when I noticed my doubt was not justified Link to comment Share on other sites More sharing options...
FastEddieB Posted June 20, 2015 Report Share Posted June 20, 2015 I trust you, but 9nm is tiny! It's just slightly more than what's used in the smallest metric fasteners on a bicycle, for instance. The bolts holding my composite gear legs call for 35 to 43 ft lbs - which is around 50nm - a whole lot more. Just wondering why the huge difference. Link to comment Share on other sites More sharing options...
Anticept Posted June 20, 2015 Report Share Posted June 20, 2015 I trust you, but 5nm is tiny! It's what's used in the smallest metric fasteners on a bicycle, for instance. The bolts holding my composite gear legs call for 35 to 43 ft lbs - which is around 50nm - an order of magnitude more. Just wondering why the huge difference. See my edit. I first posted 9nm, then for a brief moment I changed it to 5nm because I thought I looked at the wrong section, then back to 9 again when I realized I was correct the first time. For reasons to avoid confusion, can you edit your post too? For reference, the 5 newton meters is the little fairing screw torque. Anyways, these are through bolts, so they don't need to be torqued to some high amount. They just keep the leg from falling out Link to comment Share on other sites More sharing options...
FastEddieB Posted June 20, 2015 Report Share Posted June 20, 2015 For reasons to avoid confusion, can you edit your post too? Done. Still sounds light for gear leg bolts, but I guess FD knows best! Link to comment Share on other sites More sharing options...
Anticept Posted June 20, 2015 Report Share Posted June 20, 2015 Done. Still sounds light for gear leg bolts, but I guess FD knows best! They are just through bolts to keep the leg from falling out. There's a large buildup just at the socket entrance that actually takes the landing load and spreads it out, and that's where we have to put rubber padding. Link to comment Share on other sites More sharing options...
Runtoeat Posted June 20, 2015 Report Share Posted June 20, 2015 The landing gear rubber cushion area seems to need occasional inspections to make sure all is OK. Noises during taxi over bumps or during rough field landings are indication the gear needs some TLC. As Corey posts, if this condition is not fixed, the landing gear itself can be permanently damaged. My friend's CTLS landing gear was loose and inspections showed the rubbers had dislodged and these were reinstalled. The gear legs showed marks where they were rubbing the fuselage. Within a year, this happened again. This time, the repair included gluing the rubbers in with contact adhesive - believe it might have been the 1300L. It was necessary to add additional shimming rubber to custom fit the rubber to the pocked where these go. I imagine that all CT's are slightly different and there is not a "one size fits all" here. No problems with re-loosening so far. Link to comment Share on other sites More sharing options...
gbigs Posted June 20, 2015 Report Share Posted June 20, 2015 Bleeding has never been my problem with brakes...getting the fluid back in without air bubbles is a bigger issue. Getting fluid in and the air bubbles out IS bleeding...It is tough to do on the CT. Link to comment Share on other sites More sharing options...
Roger Lee Posted June 20, 2015 Report Share Posted June 20, 2015 Piece of cake. I can do any CT in minutes. If you have problems you aren't doing it right. It's one of the easiest planes I have ever done. If you use a high speed flush like the pump in my post all air is flushed out so quickly it has no chance of staying. If you use something slow like a hand operated oiler then you may have an issue. I have installed over 40 sets of Matco's on SW's and LS's and never once had a bleed issue. That was always the easiest part. If you have bleed issues you're more than welcome to give me a call. Link to comment Share on other sites More sharing options...
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