Sikh here.
This is what the 4th Guru, Guru Ram Das said to Akhbar, the Mughal Emperor, when Brahmin priests made a complaint about Sikhi. Claiming that Sikhs were disrespecting Hindus and Muslims.
"Birth and caste are of no avail before God. It is deeds which make or unmake a man. To exploit ignorant people with superstitions and to call it religion is a sacrilege against God and man. To worship the infinite, formless and absolute God in the form of a totem, an image or an insignificant or time-bound object of nature, or to wash one's sins not through compassion and self-surrender, but through ablutions; to insist upon special diets, languages and dresses, and fads about what to eat and what not, and to condemn the mass of human beings, including women, to the status of sub-humans and to deny them the reading of the scriptures and even work of every kind is to tear apart man from man. This is not religion, nor is it religion to deny the world through which alone man can find his spiritual possibilities."
Sikhi believes all humans are equal, regardless of race, gender, sexuality, religion. Sikh women do the things men do.
Although, I've got to say, most Punjabi "Sikhs" don't live up to the values of Sikhi.
Guru Amar Das Ji, the 3rd Guru, banned practices like the veil. Women didn't have to cover up and he banned them from doing so in the Gurdwara. He encouraged women to remarry if they were widowed (in India at the time, women were not allowed to remarry). He banned the practice of sati (women would burn themselves if their husband died).
ਅਵਲਿ ਅਲਹ ਨੂਰੁ ਉਪਾਇਆ ਕੁਦਰਤਿ ਕੇ ਸਭ ਬੰਦੇ ॥
aval alah nūr upāiā kudarat kē sabh bandē .
First, Allah (the One) manifested the Divine Light, all people are of the creative force (nature).
ਏਕ ਨੂਰ ਤੇ ਸਭੁ ਜਗੁ ਉਪਜਿਆ ਕਉਨ ਭਲੇ ਕੋ ਮੰਦੇ ॥੧॥
ēk nūr tē sabh jag upajiā kaun bhalē kō mandē .1.
From the One Divine Light, the entire universe came. So who is good (better than others), and who is bad (inferior)? ||1||
From Guru Granth Sahib.
So yeah, Sikhi does preach for the equality of all people.