Interpretation ID: nht91-4.30

DATE: June 26, 1991

FROM: Y. Endo -- Technical Manager, Hose Team, Meiji Rubber & Chemical Co., Ltd.

TO: Office of Chief Council -- NHTSA

TITLE: Re Inquiry for our Hydraulic brake hose assembly

ATTACHMT: Attached to letter dated 9-12-91 from Paul Jackson Rice to Y. Endo (A38; Std. 106)

TEXT:

Recently, we manufacture peculiar type of hose assemblies by our customer's request.

These hose assemblies are consisted of 2 or 3 pieces of cut hoses swaged permanetly with both ends fittings and intermediate metal fitting(s) which swaged and connected 2 pieces of cut hose at its both sides.

Please refer enclosed drawing and illustration. These assemblies are long in the whole length, but each cut hose is not loose in actual application, it is fixed by metal fitting to body side of vehicle. Please refer the illustration, the ones which be marked by red line is actually equipped example.

Concerning to the testing for these hose assemblies, there are diverse opinions in our company. FMVSS 106 specifies in its S 5.3.4 that "Tensile strength. A hydraulic brake hose assembly shall withstand a pull of 325 pound without separation of hose from its end fittings". While "Brake hose assembly" is specified that a brake hose, with or without armour, equipped with end fittings for use in a brake system". Brake hose end fitting means a coupler, other than a clump, designed for attachment to the end of a brake hose. SAE J 1401 also specifies, Brake Hose End Fitting - A coupling designed for permanent attachment to the ends of a brake hose by crimping or swaging.

Therefore, Imyself consider, Brake hose assembly shall be each one piece of hose with both ends fittings which be swaged permanently, that is 3 pieces hose multiple assembly shall be 3 Brake hose assembly.

In the Tensile strength test, multiple 3 pieces hose assembly shall be devided at each intermediate metal fitting, otherwise the test result comes to far from the real value, so I insist.

On the contrary, some one says, as far as 3 pieces hoses are connected as one assembly, the Tensile strength test shall be done as it is, only the both ends shall be fixed to the tester and pulled.

Imyself still insist, the Tensile strength test shall be done at each permanently swaged portion at the stand point of faithful interpretation to FMVSS and SAE specifications and to get accurate test result.

We can say, actual test operation is easy enough even the test of 3 devided tensile test.

Perhaps, these specifications are established without prediction of such multiple construction assembly at that time.

Then, we would like to ask your favour, please inform us your opinion or interpretation as soon as possible. This is suggested by Mr. George E. Walton, Director Safety Equipment Services of AAMVA , Arlington VA.

Thanking in advance and remain,

Attached to drawings of 2 and 3 piece hose assembly. (Graphics omitted)