JCB 214E Backhoe...loader control buttons?

Hello All,
I have a new to me backhoe, it is a 2000 model JCB 214E 4x4 with cab. machine runs great and I have no complaints. The question at hand is about the control lever for the loader, I have two buttons on the knob itself, one is the transmission dump however the other I can't seem to pinpoint the function. I though maybe it was a temp 4x4 button for driving into a pile but nope. The machine is a 214 series 3 two wheel steer 4x4 with cab and extendaboom, regular loader bucket.

P.S. I'm pretty sure with the key on engine off I can hear a relay clicking with the button, I could pull all the relays until I find the one but was hoping someone would know.
Thank you

It’s probably your Hydraulic Speed Control. There’s a solenoid on the loader valve block that dumps half your hydraulic flow back to the tank, which puts less load on the engine and gives you a little more power to the wheels.

There should be a switch with a turtle on it that does the same thing.

thats very interesting I will have to try that out. I know the turtle switch works I have noticed the hydraulic speed difference when on. so the idea being that if your driving into a pile it would give you more driving force by reducing pump load on the engine?

Yeah, that’s the idea. The button on the loader is for going into a pile, the turtle switch is for going down the road so you don’t have to hold the button down.

I don't know much but could it be for a horn? My backhoe controls have a horn button on them... Toot Toot!

Yes should be hydraulic speed control. Hit the button as the loader is raising, and you should see it slow down..

Yes You guys are correct. That is a HSC button on the loader control. thank you very much for all of your help