O cabo de travão ficou solto.

Here ficar means to become, to end up, or to be left in a certain state.

So ficou solto means something like:

• became loose
• came loose
• ended up loose

This is a very common use of ficar in Portuguese:

• ficar cansado = to get tired
• ficar triste = to become sad
• ficar pronto = to become ready / to be ready

So O cabo de travão ficou solto is not about location; it is about a change of state.

Ficou is the pretérito perfeito (simple past) of ficar, in the 3rd person singular.

• eu fiquei
• tu ficaste
• ele/ela/você ficou

In this sentence, the subject is O cabo de travão, which is singular, so ficou is the correct form.

Because solto agrees with cabo, and cabo is masculine singular.

• o cabo → masculine singular
• solto → masculine singular adjective

If the noun were feminine, you would use solta:

• A peça ficou solta.

If it were plural:

• Os cabos ficaram soltos.
• As peças ficaram soltas.

Solto usually means loose, not firmly attached, not tight, or sometimes detached/free depending on context.

In a mechanical sentence like this, it usually means the cable is loose or has come loose.

So it could suggest:

• the cable is no longer properly fixed
• the cable has too much slack
• the cable is not secure anymore

The exact nuance depends on context, but loose is the safest basic meaning here.

In Portuguese, de is very often used to connect nouns, especially when one noun describes the type, purpose, or function of another.

So:

• cabo de travão = brake cable
• literally, something like cable of brake / cable for the brake

This is very normal in Portuguese. Compare:

• escova de dentes = toothbrush
• máquina de lavar = washing machine
• sapatos de corrida = running shoes

English often turns these into noun+noun compounds, but Portuguese usually uses de.

Yes, sometimes you may hear or see cabo do travão too, and the difference is about how specific it is.

• cabo de travão = brake cable, the general type of cable
• cabo do travão = the cable of the brake, a more specific brake in a specific context

In many practical situations, both can appear, but cabo de travão is a very natural way to name the part itself.

Because this sentence is in European Portuguese.

In Portugal, travão is the usual word for brake.
In Brazil, freio is more common.

So:

• Portuguese (Portugal): travão
• Portuguese (Brazil): freio

A learner of European Portuguese should definitely know travão.

No. Cabo has several meanings in Portuguese, just as cable can in English.

Common meanings include:

• cable/wire
• cape (a geographical cape)
• corporal (a military rank)

In this sentence, because of de travão, it clearly means cable.

O means the, and it shows that we are talking about a specific brake cable.

• O cabo de travão ficou solto. = The brake cable came loose.

Portuguese uses definite articles very naturally, often more often than English does. In a normal sentence about a known object, the article is completely expected.

If you said:

• Um cabo de travão ficou solto.

that would mean:

• A brake cable came loose.

So the article changes whether the cable is specific or non-specific.

In European Portuguese, travão is pronounced approximately like truh-VAWNG, but the last sound is nasal, so there is no full final ng like in English. The ão sound is one of the classic Portuguese nasal endings.

A rough guide:

• tra- sounds reduced in European Portuguese, often closer to truh
• -vão has the stress
• ão is nasal

Also, the stress is on the last syllable:

• tra-VÃO

Sometimes in natural English translation, yes, but grammatically it is not the same idea.

• ficou solto = became / came / ended up loose
• estava solto = was loose

So if you want to preserve the Portuguese grammar more closely, came loose is often the best translation.

Compare:

• O cabo de travão estava solto. = The brake cable was loose.
• O cabo de travão ficou solto. = The brake cable came loose.

Yes, it is completely normal.

The structure is:

• O cabo de travão = subject
• ficou = verb
• solto = subject complement / resulting state

This is a very common Portuguese pattern:

• A porta ficou aberta.
• O motor ficou danificado.
• A roda ficou presa.

So noun + ficar + adjective is a useful pattern to learn.