Brakes!...What Brakes?

[Guest Roger]

Just interested to hear opinions on the brakes and especially pad wear characteristics on your Jabi.

 

Our 230C now has a tad over 100hrs and as part of the inspection we pulled the wheels off to inspect the pads, calipers and rotor. Well I have to say I wasnt overly impressed to find the pads when we pulled them apart were very flakey. Even the slightest rub against the leading edges resulted in large peices falling off.

 

The rotors look like they have been fairly hot at one stage or another and I wonder if that has ultimately affected the pads. Having said that I have worked with cars that have had the disc rotor glow red hot however on cooling the pads have not been affected in any shape or form.

 

Are the current pads too soft, am I expecting too much or do you think they could be a bad batch? It is a very small braking system for stopping something that could exceed 1/2 a tonne in weight travelling at speed. My mountain bike has bigger brakes.....and so does my dads ride-on lawnmower!

 

 

[Guest brentc]

I built my Jab when the J200 / J400's had single pads like on the LSA 55. I got about 150 hours on my first pads, but they were fairly ineffective because they were too hard (black in colour when fitted). My discs were 'burning' as a result, so I changed to new pads which are much softer and they go for around 100 hours as you have found.

 

Several weeks ago I upgraded to the dual caliper set which is probably what you guys have on your J230cw with the wavey disc. I've done a few hours and haven't got significant wear yet, however when I first fitted them they went really well but now work almost as badly as the original single calipers, but I am yet to find out what has gone wrong. I know someone who got 10 landings from his new dual calipers (pads)!

 

Do you have the upgraded brakes that allow changing of the pads without removing the wheel? I'm not sure what this upgrade costs, however it's quite handy.

 

Lets be realistic though, you have a brand new aircraft that quite a number of pilots are flying / learning to fly it. 100 hours is probably not a bad life in these conditions, especially if you're operating on bitumen. At $10 each for the pads if you have 8 of them, then $80 is quite affordable. Once you've replaced them once (especially if they are the quick-change ones) you will find it will only take you around an hour.

 

Personally, you are probably expecting too much.

 

I treat my brakes like they are an emergency item. If I can't make the intersection exit, I just back-track or taxi back the long way as it's worth it in the long run.

 

If they are flaking off I'd say that someone has probably cooked them quite severely. I operate on 1,000 metres bitumen and in normal operations I wouldn't use the brakes when landing, but rather for low speed taxi and bowser work. Additionally, I would also try to lower your idle back closer to the stall for when taxiing, otherwise people will be riding the brakes when you taxi.

 

 

[theoy]

good brakes ?

 

Me to I am light on the brakes on most landing. I have had a few experience long ago still etched in my mind like yesterday, I'm glad the Jab brakes are not mega affective and are forgiving. ;)

 

Cheers

 

Theo

 

 

[Jim Stone]

I have a J450 and gave up on the standard brakes after about 20 hours and 3 sets of pads. I now have Grove model 56-2 brakes with standard aircraft axles and tires. No significant wear isses or problems holding the AC at full power on the ground.

 

 

[Guest brentc]

If you recall previously, I recently fitted the new twin calipers.

 

Last night I had a flat tyre so took off the wheel and spats. I checked the brakes whilst I was there. I've done about 15 hours since I fitted the new pads and I've found absolutely no noticeable pad wear at all. Thinking hard about the number of landings, probably 20 in total, a couple of which were hard braking. I'm pretty happy with that after what I've heard. A mate had worn his out in 10 hours on the J400, so there must have been a change to the disc design.

 

I operate from 1,000 metres of bitumen and use brakes on all landings to get off at the 500 metre mark usually.

 

 

[tomcat]

l fly j160 the brakes are hopeless when you land you have to pump the brakes to get it to stop. The brake pads are to far away from the disc. (Sorry l am slow on the key-one finger job.)

 

 

[Jim Stone]

Sorry to here you are having difficulty with your J160.

 

If the problem is that they are really spaced out to far, you could probably shim them in with a couple washers. In my case, the issue was they overheated and fadded terribly, pumping just ground the pad down quicker.

 

The USA distributors offer upgrade kits to Matco axles, rotors, wheels, etc. I don't see them listed seperately on their web sites. The Macto URL is http://www.matcomfg.com/ . Aircraft Spruce and Chief both sell them. I would prefer either Grove or Clevelands myself, but I think that would require an adapter plate like I used. I haven't worked on or studied the J160/J170 aircraft. I remember a comment from Andy at Suncoast Sport Planes that the J170 console is to thin to allow mounting dual cylinder steering brakes.

 

 

[Geoff]

Try adjusting the brakes up.tomcat

 

 

[Guest brentc]

If you are finding that you need to pump them, then the brake likes need bleeding. Even if they are way out of adjustment they will still work if you don't run out of travel on the master cylinder first.

 

Pumping up is normally caused by air in the lines.

 

Too much travel on brake handle is caused by loose calipers.

 

'Spongy' feeling and ineffectiveness is caused by glazed discs or wornout pads.

 

A new J430 owner was recently telling me recently that he brakes fairly heavily when he first touches down to wash of 10-20 knots, then waits until much later in the landing roll and brakes again by which time they have cooled down again. It works well for him.

 

 

[tomcat]

Thank you Jim Stone, Geoff and Brentic. l will try washers and also bleeding the brakes on the weekend and let you now how it goes. l would like to land on short strip but not willing to take the risk of not stopping.

 

 

[Guest J430]

I made my own disc's from S/S plate with lots of holes (cooling and weight reduction) and purchased a slab of friction material which i cut and then drilled and counter bored for the rivets. I increased the pad area by 50% and by having the fuller disc surface I was able to utilise the biger pad area, have to also increase the backing plate area as well.

 

I think Brent might have pics I sent him.....not sure what I did with them.

 

Anyway, they have done a good 230 plus hours and only half worn! And a better fade resistance too;)

 

Been so long now since we did them I can not recall much more, but gee they work better!

 

J