Cessna brake hose??

For Grove brakes, I'll note that there's a note on the chart for 6" wheels:

"NOTE: Braking torque calculated at 600 psi brake line pressure"

And for their master cylinders:

"Max Pressure = 1,200 psi"

So, there's Grove's idea of what a standard braking hydraulic pressure is.

I had a look at their stuff, and their lineup includes 5/8" bore master cylinders and 2" caliper cylinders, the same as you'd find on a Cessna single. Much of it looks like Cleveland. And their 600 PSI number coincides with what I had calculated, and 1200 PSI would offer a healthy margin of safety.

One of these days I'll stick a gauge in the line and see what it says.
 
see post 113.....

Well that doesn't work. If you are the manufacturer in the field, why would you make special test equipment a requirement.

Time to get real, if you can test an engine in place, why can't you test a hose in place?
 
Well that doesn't work. If you are the manufacturer in the field, why would you make special test equipment a requirement.

Time to get real, if you can test an engine in place, why can't you test a hose in place?
well.....good people disagree with that too. :yes::D
 
It's only gonna matter if it fails and there's an accident.
yup....or if someone else comes behind and does the inspection and catches it.....like when it's sold. :eek:

If proper materials are used....and it doesn't leak or burst....know one will ever know it wasn't properly tested.....if it never fails.
 
yup....or if someone else comes behind and does the inspection and catches it.....like when it's sold. :eek:

If proper materials are used....and it doesn't leak or burst....know one will ever know it wasn't properly tested.....if it never fails.

When done properly it won't, When signed off properly, no one will give it a second thought.
 
Just think, If you buy the parts, then make up the hoses, aren't you the manufacturer?

I wouldn't go that far. If it's something like a doubler that you are making up, I'd say you fabricated a part in the field. If it's a hose or a line, I'd say you assembled it in the field.
 
Ok, I said I have trouble with this area. This discussion has helped things gel a bit for me.

1. A&P mechanics are authorized to perform minor repairs and minor alterations on their own determinism or say so. The "minor" term is pretty broad to the FAA. I can remove an engine, overhaul it completely, and put it back on the airplane and that is a minor repair. I can take the wing off my Piper Arrow, pull the skin off, replace a rib, put the skin back on, and put the wing back and that's a minor repair. If I take the easier path and replace the wing rib without removing the wing, I have to add a seam to the sheet metal and that makes it a major repair or alteration.

2. AC No: 43-18 Fabrication of Aircraft Parts by Maintenance Personnel is relevant to our interests here. It states:

This advisory circular (AC) ensures that parts fabricated during maintenance and alteration have an equivalent level of safety as those parts produced under the original design holder's production certificate. ... As required by regulations, such parts fabrication and their implementation must be accomplished "in such a manner...that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition." This AC is not mandatory and does not
constitute a regulation. ...

Acceptable Data. Data is acceptable to the Administrator when used within the context of maintenance, a minor repair, or an alteration if the data substantiates that the product has been returned to its original or properly altered condition. Acceptable data may establish that the fabricated part complies with applicable airworthiness standards (i.e., regulations). When acceptable data is used to substantiate that the article meets the regulatory requirements and will be returned to its original or properly altered condition, it can be considered acceptable to the Administrator.

Airworthy. ...
(1) The product must conform to its type certificate (TC) ... and
(2) The aircraft (product) must be in a condition for safe operation.

Fabrication. An act in which a part/subpart is made (fabricated) and consumed by the fabricator on the product, or part thereof, in the course of performing maintenance or alterations in accordance with approved or acceptable data, depending on the category (CAT) classification of the part being fabricated and the applicable regulations. In addition, a maintenance record
entry must be made with a description of work performed, date of completion, name of person who performed the work, and a satisfactory signature and FAA certificate number.

3. Looking at the airworthiness issue: if you are familiar with the type of data to be found in type certificates then you would know that the determination of airworthiness is mostly predicated on the second determinant, i.e. the "condition for safe operation" issue. And that is up to the mechanic performing maintenance and inspection and to the pilot performing preflight inspection. So, to a very large degree, the determination of airworthiness is at the sole discretion of the mechanic.

4. FAR Part 43 and its appendices describe what constitutes a major repair or alteration. I will not reproduce that here.

5. Conclusion: I guarantee that the type certificate for a Cessna 150 has no information as to what type of hose carries hydraulic fluid to the brake calipers. As regards the airworthiness of that hose, that is entirely the province of the mechanic. Now, can the mechanic fabricate a hose essentially identical to the original? Of course he can. He has the acceptable data in AC 43.13 and will make the determination as to the airworthiness of his repair or replacement. The real question is can he remove that expensive factory hose with the odd fittings and replace it with a standard AN fitting setup? That's an alteration. Is it a major alteration or a minor alteration? Well, that's up to the mechanic to determine. If he considers it a minor alteration, then, again, he has the acceptable data and he can go ahead and make the change and determine the airworthiness on his own.
 
Getting back to the original thread---None of the hose companies I contacted would make the hose---"Contact Cessna"

I found a number of used hoses --$225-250.
One company has a new-old stock hose for $250.00 I think that's what will wind up on the plane.

PS If you MUST pressure test a hose it can be done with a "Porta-Power" Tee and guage
 
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