Jump to content
Roger Lee

Do I have to take the front wheel pant off for a flat

Recommended Posts

Do I have to take the front wheel pant off for a flat? Good question and you need to check now before a flat out in the field and you don't have tools to remove the whole front end. It is quite easy to check. Unscrew the two bolts that hold the front wheel pant in place. Lift the wheel pant up into the notch so it bottoms out on the metal bar just above it. Now look at the front wheel axle bolt and nut. Can you easily get a wrench on both side? If yes your good to go. If no then you need to trim the wheel pant Vee notch down a little farther. It is accomplished easier with a Dremel and a sanding drum. One word about a Dremel. If you don't have one buy one. I use it for many things. Sand the Vee at the top of the wheel pant a little lower so when you lift it up you can have easy access to the axle bolt.

If you ever get a front flat in the field you will thank your lucky stars you did this in advance, it is a life saver.

post-3-0-68325200-1308960879_thumb.jpg

Share this post


Link to post
Share on other sites

Roger, what is the deal with the 4.00-6 tubes going flat all the time? Here in the south east it seems epidemic.

 

I finished an inspection on thursday around 1400. The day before I changed the NLG tube and tire. The tire held all night and most of the day. Then around 1430 we saw the tire go flat in about 5 seconds. Of course my customer was flying over to pick up his plane 5 minutes before this occured.

 

I pulled it and once again the stinkin' brass valve stem came unglued from the tube. Have you all been having this problem out west?

 

OH, and good tip for the wheel pant. I never thought to tell anyone about doing what you discibed. I use a 1 inch sanding drum on a Dremel like you. Makes a nice half moon and looks natural.

Share this post


Link to post
Share on other sites

Hi Tad,

 

Flats are caused by a couple of things mechanics and owners do. First we all know we can pick up a screw or nail on the tarmac. Not a lot we can do about this one.

Now for the regular reasons. Many times a mechanic will catch the edge of the tube when putting the wheel halves back together. Not enough to cause a leak then and there, but as soon as the wheel has turned a little and moves seating in and flexing as the wheel turns it pinches all the way through. If it were to go flat on me the first flight or two that would be my immediate thought until proven otherwise. The next really big issue is failure to check tire pressure often enough. The small 4.00-4 and 4.00-6 tires do seem to loose air faster than the larger 6.00-6 tires and tubes.

So when the pressure gets a little low and you have those cruddy Italian wheels that allow flexing, small tire bead area and a very smooth bead area coupled with low pressure the tire will absolutely turn on the wheel. Which pulls on the stem. Some are only slightly torn and slowly leak while others are ripped clean out of the tube. I have replaced many front tires that have the stem ripped completely out. If the front tire pressure is low even a taxi with a turn or two will move the tire to tear a stem. I have seen it several times and did some research with the 4.00-6 8 plys. I would now recommend that everyone carry one extra main and one extra front tire tube. I have replaced several front tubes on the tarmac with only a couple of tools, but you absolutely need to make sure your front wheel pant will lift high enough to get at the axle nut and bolt as I suggested in the other post. If you don't do this and have a front flat you life just became more complicated. In an emergency you can find a front tire tube at a hardware store which is enough to get you home. Been there and done that with other planes when away from home. If you can't access the valve stems easily to check pressure then trim the wheel pants as approved by FD in an LOA. You can notch the wheel pant (it's ok, but still a pain) or the best way is to trim all the way across each wheel pant. This also allows for a pre-flight inspection of the wheel, tire and pressure check without having to remove the wheel pant or at the least remove the wheel pant mounting screw.

 

 

 

KEEP THOSE TIRE PRESSURES UP, ESPECIALLY IN THE FRONT TIRE!

Share this post


Link to post
Share on other sites

This plane never moved in 18 hours then went flat in 5 seconds. We here have been having valve stem failures for some unknown reason. Some tubes work forever and some just go out.

 

Lockwood has these tubes and they have the same problem. It's like the fuel pump problem, some work great and some just let go. Appearantly you have a different manufacture than us here in the south east. I would like to know.

 

The tube was fine. And yes I have pinch some in the past, but this was where the brass valve stem comes unglued from the tube.

Share this post


Link to post
Share on other sites

I've had a couple flats where I pull the tube and can't find a leak. It was Ok one day and completely flat the next. I had one of the tubes I filled back with air after this happened and it sat around the shop for over 6 months without going back down. Tom

Share this post


Link to post
Share on other sites

There is apparently very poor quality control of the 400-6/13x500-6 inner tubes. I have complained to Desser about this and the salesmen I've spoken with did not appear to care much. I have had tube failures averaging about every 70 hours since my LS was new. The Sat. before last my right main failed catastrophically as I was tying the a/c down. The tube split along the sidewall near where it conforms to the inside tire radius near the top of the tire. It had 79.9 hours time in service. I maintain 37 psi in the tires and it was checked during preflight. There was no damage to the 6-ply tire and no indication of fod. I had done several t&g's on various runways and taxied about one half mile prior to failure. Lucky me. The thickness of this tube (cross section from a slice of the center of the tube measured 47 thousands. These tubes generally measure .065 t0 .068. All of my tubes (since disposal of the original European wheel barrow tubes) have been AEROCLASSIC 400-6/13x500-6 TR-87 Leakguard p/n DTR20 301 and or 300 from Desser Tire. Most were labelled Made in Taiwan although some came from China.

 

prw

Share this post


Link to post
Share on other sites

I have a 4.00-6 tire in front. I was adding air to the factory original tire about every week last winter. I finally decided to get a new Desser tire and tube and replace the factory tire and tube. I figured that I had a small pinhole leak in the tube and the tire is notorious for being thin. After tearing down the factory setup, I could not find any leaks at the valve or the tube by blowing the tube up and dipping it in water. Desser advertises that their tubes are made from a rubber compound that resists leaking. It appears that I was basically constantly loosing air a few molecules at a time right thru the rubber of the factory tube. If you have factory tire and tube, change these out to a good name brand replacement.

Share this post


Link to post
Share on other sites

Here is a thought:

 

My family used to race stock cars back in the 80's-90's. We used to run tubes in our tires with very low tire psi. We would put corn starch in the tires. This would prevent tubes and tires from binding causing tube failure and seemed to disapate heat as well.

 

I'm gonna give this a shot next time I change out a tube. I'll keep you all posted.

 

Of course this won't help with the valve stem coming unglued, but it may help with the problem of tubes tearing.

Share this post


Link to post
Share on other sites

We should all be using Talcum powder in our tires when installing tubes. Desser Tire will give you this free upon request.. This does allow the tube to move and seat properly within the tire when inflating.

 

p.s.

Don't forget to balance all your tires. They will be out of balance

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×