For instance:
Hay un camión **que va** a la playa
In such sentences, can this always be replaced with:
Hay un camión **ido** a la playa
For instance:
Hay un camión **que va** a la playa
In such sentences, can this always be replaced with:
Hay un camión **ido** a la playa
The grammatical phenomenon known in English as relative clause reduction also exists in Spanish, with the present or past participle accompanying the noun only when the auxiliary verb omitted is SER or ESTAR.
In your original sentence:
the verb in the relative does not contain "ser" or "estar" and therefore cannot be reduced as proposed.
Instead, this sentence:
can be reduced to:
Note: The present participle can only be used with dynamic or action verbs, as is the case with "ir". Therefore, the sentence below in which the verb is stative is frowned upon according to strict grammar rules:
In correct Spanish, we need to say:
Now, for a past participle to be able to form a reduced relative clause, it needs to stem from a passive voice or from a predicate containing "estar" and an adjectival participle as complement:
The sentence:
can be reduced to:
and the sentence:
can be reduced to:
No, in fact you can't really ever do that.
In older Spanish it was very possible to do this if you used the active/present participle of the verb, yente (or with other verbs, -ante/-(i)ente):
(Medieval) Hay un camión yente a la playa.
However, these forms have for the most part lost their verbal uses and are now considered merely adjectives. As such, it's harder and often impossible to use them if the verb has any complements (such as is the case with your sentence, where a la playa is a locative adverbial complement, or complemento circunstancial de lugar in Spanish).
If you wish to replace que fue V.-ado/-ido, you can replace with the past participle. So for instance, given the sentence
Hay un camión que fue comprado por una persona.
I can replace the que fue comprado with simply comprado (matching for gender and number) to get:
Hay un camión comprado por una persona.