DRIFT BRAKE/LINE LOCK OPTIONS
 

I was looking at a couple of cars i have that will be scrapped after all the usable/sell-able parts are removed last night and had a thought. I've been working on how to install a good drift brake on my 450slc track car im building. I have a foot ebrake mechanism that i considered mounting with the pedal up, next to the shifter with a longer handle for leverage. The little drum brake in there really isn't designed to be slammed on at speed to lock the rears up and may not even be able to with big hot sticky tires though. I could mount two calipers above and below each other with one leg of each using the stock mounting points, plus custom brackets on the open leg welded to the control arm. I'm not crazy about the idea of welding on there with the bearings, grease and seals installed though, and its a serious job to remove and replace all those parts without the factory tools.
So my idea is using an ABS pump/valve body( ihave a 95 r129 and a 89 w126 available) with manual switches or button to lock the front or rear wheels when wanted. I wouldn't resell the ABS parts just for saftey concerns of someone using a part that could have issues so its scrap metal anyway. When the abs system isn't energized it functions as a normal brake system. I disable abs in any car I own with it anyway, and haven't had any issues(besides not having abs try to kill me by releasing the brakes in the snow!). So from what i have found so far is that the valves have three positions.

In position one, the valve is open; pressure from the master cylinder is passed right through to the brake.
In position two, the valve blocks the line, isolating that brake from the master cylinder. This prevents the pressure from rising further should the driver push the brake pedal harder.
In position three, the valve releases some of the pressure from the brake.

The pump in the ABS is used to restore the pressure to the hydraulic brakes after the valves have released it. A signal from the controller will release the valve at the detection of wheel slip. After a valve release the pressure supplied from the user, the pump is used to restore a desired amount of pressure to the braking system.

So I think I should be able to determine which solenoid valve needs to be activated with the pump to lock the rears for drifting or the fronts for a line lock for drag racing(or just ridiculous tire shredding). Anyone have any thoughts about this idea or issues that could arise? One thing i have thought about is the pump over pressurizing the system when manually activated and possibly blowing lines out since it pulses on normal activation. maybe there is a max pressure bleed off built in but these are the small details i just havent dealt with with my muscle car and vintage jap and mercedes experience.