Nate Nagel wrote:
> Does anyone have a link to any law or standard that allows or prohibits
> their use?
>
> Was having a discussion with a mechanic yesterday and the wrench was
> saying that it was easier to use a compression fitting than double
> flaring and he didn't have a problem using them; my position was that if
> I needed to replace a hard line where it was easier to cut and splice in
> the middle than rerun the whole thing that I would always use a double
> flare and a union, because of the impossibility of the fitting blowing
> apart under pressure save for a failure of the tubing itself. the
> discussion was prompted because he was looking at a repair I'd done on a
> friend's vehicle when the rear brakes had failed; the hose to the rear
> axle had failed and replacement required replacement of both the axle
> lines and the back half of the rear body line due to rust, and he'd
> noticed that the one splice that I'd done was a double flare union.
>
> However when I went to research the issue I see a lot of opinions that
> "it's illegal" to use compression fittings but no links to actual
> references nor could I find anything in the pertinent safety inspection
> standards (NB: I'm not a vehicle inspector nor have I ever been, so I
> don't know if there is an "unwritten rule" that compression fittings =
> failure.) If anyone has any knowledge of this issue I'd appreciate your
> input esp. if it is specific to VA, MD, or DC.
>
> I also certainly hope that the mechanic was referring to a good steel
> Swagelok fitting (which is at least rated for the pressures used in an
> automotive brake application) and not the brass ones like you'd use to
> hook up an icemaker!
>
> nate
>

Maryland inspection regarding brakes.

Procedures: Reject Vehicle If:
(a) Hydraulic System—Visually inspect condition of hydraulic system.
(i) Inspect wheel cylinders for leakage and operation. Do not
remove dust covers.
(ii) Inspect hydraulic hoses and brake lines for leaks, cracks,
chafing, flattened or restricted sections, improper support, rusting
causing pitting, and improper material.
(iii) Inspect master cylinder for leakage and fluid level of all
sections. (Be sure no dirt gets into reservoir when cover is removed and
that the gasket is serviceable.)
(a)
(i) Wheel cylinder leaks or fails to operate.
(ii) Hoses, or brake lines are cracked, chafed, flattened,
restricted, or are rusted and pitting is visible, are improperly
supported, or lines have been repaired or replaced with copper tubing or
other material not designed for hydraulic brake lines. Hoses or brake
lines are mounted to contact wheels or body during steering or
suspension movement.
(iii) Master cylinder leaks.
(iv) The fluid level in any section is less than 1/2 full.
(v) The gasket does not properly seal master cylinder.

Compression fittings fall under the "material not designed for hydraulic
brake lines"

Connecticut:

BRAKE LINES - Tubing must be steel and properly attached and supported
(at least every 18")
and hoses shall not be kinked, twisted, or frayed. Hoses must not be
under tension during full right
and full left-hand turn, or during full compression or full extension of
suspension. Automotive
stainless steel tubing and braided hoses are acceptable but compression
fitting will not be allowed.



In NY they are specifically called out as an automatic fail if used on
any part of the brake system as well.


--
Steve W.