Dual-puck Cleveland brakes

[zero.one.victor]

I've noticed that some ( usually) early model 170's have gear legs that are kinda bowed out. I'm not sure if they are fatigued,or were always that way. The later (lady?) legs are heavier duty,I think. A better mod than 180 legs might be to install the later 170 legs. The original 180 legs were swept farther forward by the factory in I think 1955,I believe they felt that improved ground-handling especially when they switched from the A engine to the slightly heavier O-470-J. The earlier 53 & 54 legs might be best for installation on a 170. Mine are later model legs,they were already on the plane when I bought it. The forward rake of these later legs is not necesarily a good thing on a 170. I wonder if stock (early) 170 legs can be re-arched to get rid of the bowed-out condition? I have heard that they re-arch the stock leaf-spring gear legs of a 150 taildragger conversion to raise the 3-point attitude up to where it belongs. 180 legs might be too much of a good thing with regards to being stiffer,transferring more stress to the gearbox? Kinda like a BirdDog tailspring transferring more stress to the tailcone & mounting bracket?

Eric

[rudymantel]

Eric, I have the "lady leg" late model 170 gear which works just fine.
I need more braking power to taxi straight in a crosswind, alternatively, a locking tailwheel would help a lot.
Does anyone else have this problem ?
Rudy

[zero.one.victor]

I have a little trouble taxiing in a strong X-wind,and I have the big brakes. Downwind brake and some power overcomes it though.
Rudy,when you look at your airplane head-on,do your gear legs appear straight,bowed in toward the middle of the plane,or bowed out?
I have a friend with a ragwing whose gearlegs are splayed out big-time,I guess they work alright but from the front his airplane looks like an old horse that's ready for the glue factory.
Speaking of ragwings,Larry,did you ever get yours back home?

Eric

[rudymantel]

Eric, my gear legs are pretty straight. And after I bought my plane two years ago I aligned the wheels and installed a new tailwheel assembly and main tail wheel spring. I also removed the 800x6 tires and put on 600x6's which helped the taxiing/braking some.
Most times I'm OK except this time of year when the winds get strong- it's darn annoying. Last Friday we had a 20-25k wind and I scrubbed a flight because I had so much trouble taxiing out to the runway - I kept turning into the grass! The tower guy said that it looked like my airplane had a mind of its own !
Rudy

[N1478D]

Something must be wrong Rudy! It is not fun, but I can taxi in 30 knt winds, but I am always happy to be either in the hangar or airborne. As the winds' strength increases, more brake pedal pressure has to be applied to keep the nose straight, but the airplane never goes where I don't want it to. The bracket that holds the rudder/brake assembly to the tunnel broke this past summer. Wonder if yours is allowing to much play, or if you do not have enough pressure for some reason?

[rudymantel]

Joe, it doesn't make sense- the brakes look good, the pedal isn't soft, I replaced the discs recently. It's a head-scratcher...
Rudy

[N1478D]

Rudy, curious if you can lock your brakes after touchdown and the weight is on the wheels. Mine can. I cannot think of anything that would weaken your brake system other than silicon or some other type of lubricant being on your rotors or pads. You're right, it is a real head scratcher. Brake fluid is hdyroscopic(sp) - it will abosrb water, wonder if it would help to replace your fluid?

[N1277D]

My 170A has the 180 gear legs with the cleveland double puck brakes. It handles ok with winds up to about 25 kts on the ground. Above that it just will not turn downwind easily- the tailwheel will free-wheel, brake loose, with that much of a direct crosswind. Ive landed it in a 25kt cross wind up in the Yukon and swore never again will I do something so stupid. The guy in the tower called and said he did not like my crab angle; neither did I, then warned me about the downdrafts over the cliff. Even with the 180 gear and double puck brakes it wants to ground loop or skip sideways going straight down the runway as you slow down with strong cross winds. More than 25kts crosswind is not good for the 170, as is landing downwind with more than 10 to 15 kts quarterlying tailwinds.

[blueldr]

To 1478D--- Joe, If you have been putting "Brake Fluid" in your C-170A brakes (it IS hydroscopic), you had better get a qualified mechanic to clean out the system. They are properly serviced with red spec hydraulic fluid, a petroleum oil. They do not mix.

[N1478D]

To 1478D--- Joe, If you have been putting "Brake Fluid" in your C-170A brakes (it IS hydroscopic), you had better get a qualified mechanic to clean out the system. They are properly serviced with red spec hydraulic fluid, a petroleum oil. They do not mix.

Hi BL,

I service the brakes with MIL-H-5606 hydraulic fluid, just referred to it as brake fluid. Did not know that the 5606 is not hydroscopic, very glad to learn that. Keep an oil can with a long pump squirt spout to use for the difficult access.

Thanks for the warning though.

[GAHorn]

The recent (last 10 years) changes to brake lining materials has affected the capability of brakes to "hold". Asbestos has been removed from the formulation, and "metallic" linings are now the rage.
Metallic linings require proper break-in procedures. It amounts to two or three long, hard, braking stops without allowing any cooling period between the brake applications. Next, let the brakes cool 5 minutes or sor, and test the brakes to see if they can hold the aircraft while full power is applied. If not, then the break-in must be repeated.
Be careful not to overdo this. You don't want to cook the caliper seals or fluid.
Changing the fluid will not improve braking action unless the brakes feel "spongy" or soft. If the incorrect fluid has been used, then the hoses must be replaced and the calipers must be rebuilt/resealed and/or overhauled.

[rudymantel]

I'm glad to report that I just received field approval for installing the Cleveland double-puck brakes (Parker Hannifin Kit 199-62). This kit comes with STC SA63GL which applies to 180's. 185's and 206's but not to 170's hence the need for a field approval.
Special thanks to Shawn (ak2711c) for sending me the 337 on which this approval was based.
The kit which consists of wheels and brakes cost $896 from Spruce.
I also am buying two solid axles Part No,. 0541124-1 from Hill Acft in ATL -cost $ 223.55 ea. (See Solid Axle topic).
This forum has really been a great help- super bunch of guys!
Rudy

[H. Mark Smith]

in the past, only occasionally, I have seen clevland brakes not work correctly. IT was becasue of years of operating in water, mixed with brake lining material and the fact that the brake housing is MAGNESIUM and the brake pistons ALUMINUM, there gets corrosion going and it can lock the piston in the housing... Single puck clevlands, with good linings and even with 8:00x6 tires will (1) hold the airplane during a full powerrunup on dry ground (2) provide adequate braking even in 20kts crosswind. Youcand dismantle the brake, clean the piston and housing and reasssemblewith new "O" rings. Actually I bead blast the housing and then
use STITS MAGNEdyne pickling solution, then reassemble everything, blleed the brakes and give her a whirl.....

[rudymantel]

Mark, my brakes are in very good condition, no corrosion. Per George's suggestion, I "broke them in" to get a glaze on the metallic lining and that helped but I've deceided to get the double-pucks and solid axles. I expect to get the axles today and plan to install the new brakes later this week.
Rudy

[Dave Clark]

I go through the cleanup process on the calipers at every Spring annual. I've found that otherwise the corrosion in the caliper bores makes them sticky. One Summer with the 181 they just got harder and harder pedals with the brake efficiency declining until I broke down and cleaned things up. I also learned not to use "Simple Green" type of cleaners as they start the corrosion going quickly.

Incidently in my restoration I pulled the masters and found the fuselage point where the right brake mounted was broken and needed a repair. The bolts for both masters were loose and the mounting brackets looked like they were shop built out of aluminum. I bought new (steel)brackets from Cessna at a pretty low price. They must be a common part with a lot of other models so that their production runs are efficient. Anyway this is an area that is a known problem and should get a close look at every annual.