Mababa ang presyon ng gulong dahil sa pagkasira.

In Filipino, it is very common for the predicate to come first.

So in Mababa ang presyon ng gulong, the structure is roughly:

• Mababa = low
• ang presyon ng gulong = the tire’s pressure / the pressure of the tire

A very literal rendering is:

• Low is the tire’s pressure.

This sounds unusual in English, but it is normal in Filipino.

You could also say:

• Ang presyon ng gulong ay mababa.

That has the same meaning, but the original version is more natural and common in everyday speech.

Ang is a marker that usually points to the topic or subject-like part of the sentence.

In this sentence:

• ang presyon ng gulong

is the part being described by mababa.

So ang does not mean exactly the, although in many translations it may feel similar. Its job is grammatical, not simply to mark definiteness like English the.

Ng here marks a relationship similar to of or apostrophe-s in English.

So:

• presyon ng gulong = pressure of the tire
• more natural English: the tire’s pressure

This is a very common pattern in Filipino:

• bahay ng lalaki = the man’s house / the house of the man
• kulay ng kotse = the car’s color

In your sentence, gulong is the thing whose pressure is being talked about.

It can mean wheel, and in many everyday contexts it is also used for tire.

So presyon ng gulong is naturally understood as tire pressure, because pressure is associated with the tire, not the whole wheel assembly in a technical English sense.

If the context is vehicles, Filipino speakers will usually understand what is meant.

No. Filipino often does not need a separate verb equivalent to English is/are in this kind of sentence.

So:

• Mababa ang presyon ng gulong.

already means:

• The tire pressure is low.

There is no missing word. That is a complete and correct sentence.

Dahil sa means because of.

It is a common expression:

• dahil sa ulan = because of the rain
• dahil sa trapiko = because of traffic
• dahil sa pagkasira = because of the damage / because of the breakage

It is treated as a set phrase in many cases, so it is best to learn it as a chunk: dahil sa = because of.

Pagkasira is a noun meaning something like:

• damage
• breakage
• being damaged
• malfunction/failure depending on context

It comes from the root sira, which relates to being broken, damaged, or not working properly.

So:

• sira = broken / damaged
• pagkasira = damage, breakage, the state/event of being damaged

In this sentence, it refers to the damage that caused the pressure to become low.

Using pagkasira makes the idea more noun-like and abstract, similar to damage or breakage in English.

Compare the feel of the two:

• sira often directly describes something as broken/damaged
• pagkasira refers more to the condition, event, or fact of damage

So dahil sa pagkasira sounds natural for because of the damage.

Yes. That is also correct.

Compare:

• Mababa ang presyon ng gulong dahil sa pagkasira.
• Ang presyon ng gulong ay mababa dahil sa pagkasira.

Both mean essentially the same thing.

The first is more typical of predicate-first Filipino word order.
The second is also common and may feel a little more structured or formal because of ay.

Not necessarily.

Pagkasira is broader than puncture. It just means there is some kind of damage or failure.

If you want to be more specific about a puncture or hole, Filipino might use words like:

• butas = hole
• nabutas ang gulong = the tire got punctured / the tire has a hole

So your sentence does not automatically mean a puncture; it could refer to any damage causing low pressure.

Presyon is a borrowed word, ultimately from Spanish and related to English pressure.

This is very common in Filipino. Many everyday words, especially for technical or formal concepts, are borrowed or adapted from Spanish or English.

Even though it is borrowed, presyon is a normal Filipino word and fits naturally into Filipino grammar, as in:

• mababa ang presyon
• mataas ang presyon

A very literal breakdown would be:

• Mababa = low
• ang = topic marker
• presyon = pressure
• ng gulong = of the tire
• dahil sa = because of
• pagkasira = damage / breakage

So very literally:

• Low the pressure of the tire because of damage.

That is not good English, of course, but it helps show how the Filipino sentence is built. A natural English translation would be:

• The tire pressure is low because of damage.