brake trouble

ok did the brakes both sides fixed the seals on right side leaking rear-end grease so change both sides both master cylinders hone out slave cylinders bleed out air had brakes moved it around a bit now petal hard again and left brake lock up can open bleeder and it will become free again you hit the left brake petal then it lock up again or the main brake for both on the right I have a power shuttle just can't figure this one out

The make & model of your backhoe will be a big help here @rickwey

Sounds like one of your lines has broken down inside and you have a flap making a sort of check valve.

It a 1980 580C construction king and Paul I replace both rubber lines and both master cylinders only thing I didn't replace was the slave cylinders I horned them out and cleaned them up and replace some metal brake line on left side alone with new brake pads

I'm not familiar with your backhoe, but if the master cylinder/s work the way they do on a car or light truck, there needs to be a little free play in the brake pedal adjustment.

Ok, you open the bleeder and the brake releases. Get it to lock up again and then loosen the line on that side's master cylinder coming right out of the master cylinder. Does it release? If it does, you have a problem with the master cylinder, possibly the pushrod is out of adjustment like a previous poster mentioned.

If it doesn't release when you loosen the line at the master cylinder, then you know the problem is downstream from that, if you have a rubber line or other components in there, you can keep locking them up and then cracking lines till you figure out the problem.

You might have a problem with the steel line for the left side. I would check that out and recheck your rubber line even though it's new.

The return springs on the pivot arm at the slave cylinders are in place?

yes the springs are good still strong and tight i'll double check the lines again tomorrow