c172k hard brake line replacement

[AlphaPilotFlyer]

my right hardline looks a bit weathered and thinking about replacing it ... it looks like standard automotive 3/16" steel line with standard double flare ends. wanted to get input on anyone with experience replacing the line .... looked up some online photos of used lines and seems easy bends to make with standard bender hand tool......seems most difficult part would be installing complete line and fishing thru floor and installing connection to master cylinder.... the cessna mx manual pretty basic so any input welcome....

 

[Dan Thomas]

Aircraft lines are flared at 37 degrees. Automotive lines are flared at 45 degrees. They don't mix.

Aircraft brake line is normally 5052 aluminum, not steel.

You might also replace the flex lines at the master cylinders. They get ignored and turn hard and brittle with age and will start leaking. The hard lines are not attached directly to the master cylinders. Those cylinders move.

 

[Ed Haywood]

Not hard to make. Buy extra lengths of tubing so you can screw up a few times. Get the proper grade of aluminum tubing for your variant.

Bends are easy with a tubing bender. Make sure you have the proper flaring tool for AN fittings.

 

[AlphaPilotFlyer]

Thanks….the line is painted so may likely be 5052, especially with pressures likely below 500psi….. looking at parts diagram now I see the line is in short sections between bulkhead fittings, with last run from just inside strut cover to calibre. I expect I only need to replace the external run but will take a close look at all, including the hose from master cylinder. Speaking of hoses… I see some early c172 having a hardline all the way to calibre , and some with a short hose between calibre and hardline. I can’t see anything in parts diagram I have access to re if this hose is included, or if a hard line all the way to calibre….. do older models just have hardline? If so, would adding the hose be an improvement?

Thanks again. Will always take a good look at part being replaced to confirm it’s a direct match but good to know what to expect.

 

[kyleb]

If you have any friends who are building aircraft, they will almost certainly have the bending and flaring tools you need.

 

[Magman]

Pre-1966 is good your brakes. They did not float so they did not need a hose. When Cleveland brakes are added per STC A short length of hose is generally preferred.

 

[AlphaPilotFlyer]

thanks again for input....got all the flaring., cutting wheels and benders from last exp build. just need the time now

 

[Fffflats]

Not hard to make. Buy extra lengths of tubing so you can screw up a few times. Get the proper grade of aluminum tubing for your variant.

Bends are easy with a tubing bender. Make sure you have the proper flaring tool for AN fittings.

And also a little extra tubing allows for flex during landings so as to reduce likelihood of cracking your new line.