Redensartenindex has no entries for "reparieren" or "beheben", which is how they translate *fixen*², incidently.

"Brechen" is not metaphoric and unlikely to lead to good results. The index only has *zu Bruch gehen*. *Kaput* has no entry either.

Without idiomaticity one might say,

> Fass das nicht an, **bevor es noch kaput / zu Bruch geht**

Interestingly, *ain't* seems to begin as a contraction of *am not*, but it has a side of *have not*: “As a contraction of *have not* and *has not*, *ain't* derives from the earlier form *han't*, which shifted from /hænt/ to /heɪnt/, and underwent h-dropping in most dialects.” (https://en.wiktionary.org/wiki/ain't#Etymology)

We never say *\* ja wenn es nicht gebrochen hat*. We say *what doesn't kill me makes me stronger* ("was mich nicht tötet, macht mich stark").

It is obvious that English *brook*, the regular cognate to German *brauchen*, has largely passed out of usage. For example, "Can you break a twenty?" may belong here: *can you do me a favour, if you could use a large bill, trade me your small change?*, ie. *brauchst du ...?*


The meaning is conveyed by *to break in (new shoes, a young horse)*, cp. German *anbrauchen*, more often *anbrechen*, but chiefly *verbrauchen*, never ever to be confused with *verbrechen, Ehebruch*, though *Missbrauch* is close and *Willen brechen* may said of horses.

In this view, there is only one plausible cognate to *fixen*, left to the imagination of inclined readers, which explains why there is no German cognate of the phrase in living memory. German *Fixer* "heroin junky" might relate to this.

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In addition, the noun Ger. *Brauch* ("custom, tradition") presents problems. *Traho* as well as *alt-her-ge-brachtes* might suggest a relation to *bringen*, to say the least (compare *hand-me-downs*).

Therefore one might say:

> **Wenn es nichts bringt**, dann lass es halt