I work as a diesel truck mechanic at a truck dealership in CA. I have only worked for them on a flat rate per hour basis. For ex., if I was given a job that my employer is charging the customer 5 hours for, then I would also get paid 5 hours (at my usual hourly rate), whether I did it in 3 hours or 8 hours. I could sometimes work a 40 hour week, but get paid for 50 hours because I had accrued 10 hours "gain time" (completing all work assigned in 10 hours less than the flat rates).

But for the last several months, when I have been beating the flat rate time, they have frequently been taking a substantial part of my gain time away from me. For ex, I just did a 5 hour flat rate job in 2 hours and was only paid 2.5 hours instead of the 5 hours that customer was charged.

Since I have complained about what seems to be an undocumented change in policy many times, the foremans now mostly refuse to even tell me what a job is supposed to pay (what the flat rate for the job is).

Is what they are doing with my pay now (skimming as far as I am concerned) a violation of CA and/or Fed labor law?

This is an over simplification, but basically there are two different types of laws - Labor law and Contract law. Labor law is for purpose of your question things like minimum wage and overtime. If these are conditions you are subject to (certainly on MW, maybe on OT), then there is nothing that can be done to waive these requirements. Labor law is basically something imposed on the employer that the employer can do nothing to avoid.

Contract law is very different. CA minimum wage is $8/hr. An employer can legally pay more then that, but is not required to pay more then that. Let's say that I hire Bob for $10/hr. All work done will have to be paid at $10/hr. HOWEVER, unless I have a formal contract with Bob, there is nothing in federal or California law that says I cannot change Bob's rate on a go forward basis to something else as long as MW rules are followed.

-----

Which brings us to your question.
- Your employer must pay you MW, and maybe OT (you might be subject to the Auto Dealer specific exceptions for mechanics and overtime, depending on the nature of your employer's business).
- However, unless you have a formal contract with your employer that they will NEVER change your rate of pay, what you describe is not necessarily illegal. Now I am not you. I have not read every piece of paper that you have signed and have not heard every word your employer has told you. If you think that you have an actual contract, then you need to talk to a local attorney. But based on what you have said, I do not see a Labor law per se being violated.

I work as a diesel truck mechanic at a truck dealership in CA. I have only worked for them on a flat rate per hour basis. For ex., if I was given a job that my employer is charging the customer 5 hours for, then I would also get paid 5 hours (at my usual hourly rate), whether I did it in 3 hours or 8 hours. I could sometimes work a 40 hour week, but get paid for 50 hours because I had accrued 10 hours "gain time" (completing all work assigned in 10 hours less than the flat rates).

But for the last several months, when I have been beating the flat rate time, they have frequently been taking a substantial part of my gain time away from me. For ex, I just did a 5 hour flat rate job in 2 hours and was only paid 2.5 hours instead of the 5 hours that customer was charged.

Since I have complained about what seems to be an undocumented change in policy many times, the foremans now mostly refuse to even tell me what a job is supposed to pay (what the flat rate for the job is).

Is what they are doing with my pay now (skimming as far as I am concerned) a violation of CA and/or Fed labor law?
I doubt they can do that talk to an attorney this seems awful crooked. If the employer charges the customer 5 hours, and it takes you six. Then the employer pays 5, if the employer charges the customer 5 it takes you 4 you should still be paid 5. Otherwise why even have a flat rate or an estimator.
JoeC