Wir ziehen den Bremsbelag fest.

Because festziehen is a separable verb.

The full verb is festziehen, but in a normal main clause, German splits it:

• Wir ziehen den Bremsbelag fest.

So:

• ziehen = the conjugated part, which goes in the usual verb position
• fest = the separable prefix, which moves to the end

This is very common in German:

• Ich mache die Tür auf. = I open the door.
• Wir ziehen den Bremsbelag fest. = We tighten the brake pad.

In the infinitive, it stays together:

• Wir müssen den Bremsbelag festziehen.

The actual verb is festziehen.

On its own, ziehen usually means to pull or to draw.
But festziehen has a more specific meaning: to tighten.

So in this sentence, you should not translate it word-for-word as we pull the brake pad firm. Instead, treat festziehen as one vocabulary item.

Because Bremsbelag is the direct object of the verb, so it is in the accusative case.

Bremsbelag is a masculine noun:

• nominative: der Bremsbelag
• accusative: den Bremsbelag

Here, wir is doing the action, and den Bremsbelag is receiving the action:

• Wir = subject
• den Bremsbelag = direct object

That is why German uses den.

You usually learn the noun together with its article:

• der Bremsbelag

There is no reliable universal rule that tells you just from the meaning that it must be masculine, so the best habit is to memorize nouns with their article.

Once you know it is der Bremsbelag, the accusative form den Bremsbelag makes sense.

In this sentence, fest is best understood as part of the separable verb festziehen.

It originally relates to the idea of firmly/tightly, but grammatically here it functions as the verb’s separable prefix, not as a separate adjective describing the noun.

So:

• not really the firm brake pad
• but rather to tighten the brake pad

It is present tense:

• wir ziehen = we tighten / we are tightening

German present tense is used more broadly than English present simple sometimes. Depending on context, it can mean:

• a general action
• something happening now
• an instruction or step in a process

In a technical or instructional setting, Wir ziehen den Bremsbelag fest could sound like:

• We tighten the brake pad or
• Now we tighten the brake pad

German main clauses usually follow the V2 rule: the conjugated verb comes in the second position.

Here:

1. Wir = first element
2. ziehen = conjugated verb in second position
3. den Bremsbelag = object
4. fest = separable prefix at the end

So the structure is:

• Subject + finite verb + object + separable prefix

That is why Wir festziehen den Bremsbelag is wrong.

Yes. That is grammatically correct.

German lets you move elements to the first position for emphasis, as long as the conjugated verb still stays in second position:

• Den Bremsbelag ziehen wir fest.

This version puts more focus on den Bremsbelag.

But the more neutral basic order is:

• Wir ziehen den Bremsbelag fest.

It is a compound noun, which is very common in German.

It is made from:

• Bremse = brake
• Belag = lining, covering, pad

Together:

• Bremsbelag = brake pad / brake lining

German often combines words into one noun where English may use two separate words.

This is a normal pattern in German compounds. The first part of a compound often appears in a shortened or linking form.

So:

• Bremse
  • Belag becomes
• Bremsbelag

You do not need to analyze this too deeply every time; it is simply the standard compound form you learn as a word.

Very often, yes.

festziehen is commonly used for tightening physical objects such as:

• screws
• bolts
• nuts
• clamps
• straps

It usually suggests making something secure or tight.

That said, the exact natural English translation can vary by context:

• tighten
• secure
• fasten tightly

With a modal verb or another structure that uses the infinitive, festziehen stays together at the end.

For example:

• Wir müssen den Bremsbelag festziehen. = We must tighten the brake pad.
• Es ist wichtig, den Bremsbelag festzuziehen. = It is important to tighten the brake pad.

This helps learners see that festziehen is really one verb, even though it splits in a main clause.