I just installed a Biondo line lock on my car. The solenoid clicks and engages the front brakes but when you try to do a burn out the power of the rear wheels overcome the front brakes and the front wheels start to roll. This car only makes about 450 HP. I backed off the rear brake adjustment, lines are bled properly (good firm pedal). I even removed the proportioning valve thinking that was the problem. All the lines going to the front brakes are new as well as the master cylinder, calipers, brake pads, and line lock. Any suggestions?

Is the line lock new?

I have heard they have a life span. Mine still works, and is 5 years old. Pretty light use.

What happens when you do a power brake without the line lock? Will power of the rear wheels overcome the front brakes and the front wheels start to roll?

If it did not hold it before it is not going to with the line lock now.

if you can foot brake it and have it not roll, the problem is the line lock.

can you pump the pedal any harder prior to turning the line lock on? maybe you just didn't generate enough line pressure before locking the front brakes?

Are the fronts rolling or sliding?

Two ways to go about installing that line lock.....The first way is how I did it on my one 70 Charger. The second way I think is better.

1) install it on the front, two real good deep pumps and hit the switch, you should not be rolling.

2) Install it on the rear brakes, hit your switch to lock the solenoid shut and your foot will be applying a stronger pressure on the front brakes than a line lock could. You have foot pressure versus closed pressure. Personally, I should have done it this way but you live and learn.

If you put the line lock on the rear you may want to put a light on the switch to make sure you turn it off. Otherwise you will have no rear brakes down track.

Hold the button on and pump through the line lock..My Biondo did the same thing till I got the advice from a long time racer..You can pump through some linelocks...Thats why they label the ports, you can force the check off the seat on the "in" port, but it will positive check on the brake/out port...

A lot of racers use a toggle switch so it's either on or off.

Didn't say it was legal. Just said people do it.

Here is the answers to the questions asked by those who responded:

1) The Biondo Line Lock is brand new.

2) I have tried hitting the switch and pumping the brakes after the switch is engaged.

3) I also pumped the brakes prior to setting the line lock. No change.

4) When the line lock is set, the front wheels will turn when the rear wheels over power the fronts.

5) When I use the foot brake only (no line lock)the fronts will lock down and slide on the pavement when the rear wheels put out enough steam to move the car.

6) The master cylinder, calipers, pads, plumbing, and line lock are all new. I have a real good firm pedal so I am asuming the brakes are bled properly.

I called Biondo today and they said that I have done everything right as far as installation. They are sending me another line lock unit to try. I'll let you guys know what happens. If anyone else has any suggestions, feel free to respond.
Thanks to all who responded.

I had a similar occurrence on my car - nothing new or different, though - and it was because I didn't push the pedal hard enough. Try it after STANDING on the brake pedal like you're trying to bend it, and see if there's any difference. Put some water under the rear tires, too.

I tried watering down the slicks and the ground they sat on. I thought I was pushing down on the pedal pretty hard. I will try your advice and really push hard down on the pedal. Thanks