New line lock beginning of year, worked fine all season until last 3 weekends. Holds 1 pass, not the next. Back up, try again and works. Always plenty of water in box. Activated to K&R toggle and panel. Bad lock or something else going on. Thoughts?

who's line lock? by your description it's sounds like a power or ground issue. check them and the switch. If all good, bleed the brakes.

quote:

Originally posted by 1320racer:
who's line lock? by your description it's sounds like a power or ground issue. check them and the switch. If all good, bleed the brakes.

B&M. Should add, it partially holds but pushes through with higher rpm's. Did re-bleed brakes, same thing

Not familiar with B&M. Did you use any teflon tape on any fittings? A piece can break off and cause problems. Is the LL rebuildable like a Hurst?

that sounds like air in the system. Talk about your method of bleeding.

quote:

Originally posted by Eman:
Not familiar with B&M. Did you use any teflon tape on any fittings? A piece can break off and cause problems. Is the LL rebuildable like a Hurst?

That is what I was thinking and then saw your post.

After you energize the line lock, can you pump the brake peddle multiple times to get it firm?

quote:

Originally posted by Eman:
Not familiar with B&M. Did you use any teflon tape on any fittings? A piece can break off and cause problems. Is the LL rebuildable like a Hurst?

Paste not tape on the fitting into master cylinder and into line lock

quote:

Originally posted by markemark:
After you energize the line lock, can you pump the brake peddle multiple times to get it firm?

Yes pedal stays firm no matter how many times you pump it before or after setting the lock

how did you bleed the brakes

We have had the opportunity to test a lot of “Hurst style LL” and I can tell you that consistence in holding pressure is lacking. I would recommend that anyone buying a new LL to pull it apart and at minimum to clean and inspect. This is the “Hurst style LL” that many companies rebrand.

quote:

Originally posted by 1320racer:
how did you bleed the brakes

RH rear
LH rear
RH front
LH front

Again was fine all year until last few races

I meant the method used to get the air out of the system

I looked that solenoid up and it doesn't say it's rebuldable.
When my LL acted up I jacked the car and set the LL and it took a short time and I could rotate a front wheel with the LL activated. It was bleeding down from trash on the needle. Mine is a Hurst been in the car over 20 years and the trash was operator error with teflon tale on the pipe fitting.
That B&M is like the Moroso I had on one car, you don't get the extra pumps like a Hurst.

quote:

That B&M is like the Moroso I had on one car, you don't get the extra pumps like a Hurst.

After viewing B&M instructions I agree possible. The best way to test what you have is to First energize the LL and then starting pumping the peddle. Should pump at least 2 or more times to be hard if Hurst style.

quote:

Originally posted by Eman:
I looked that solenoid up and it doesn't say it's rebuldable.
When my LL acted up I jacked the car and set the LL and it took a short time and I could rotate a front wheel with the LL activated. It was bleeding down from trash on the needle. Mine is a Hurst been in the car over 20 years and the trash was operator error with teflon tale on the pipe fitting.
That B&M is like the Moroso I had on one car, you don't get the extra pumps like a Hurst.

Yes it definitely acts like its bleeding off once set. I'm going to pull it off and take a look at it but went ahead and bought another one just in case.

I didn't want to guess so I just jacked it up and saw it bleed off as I put pressure on the frt. wheel to turn. I just took my Hurst apart and cleaned and resealed it, that's also how I learned all O-rings are not created equal so I then ordered the correct material O-rngs.
One thing, you mentioned using thread sealer on the MC, MC shouldn't have pipe threads so the flare is what seals it and the nut just tightens it shouldn't use sealer on flare nuts.

Does the LL go through a delay box?

quote:

Originally posted by Yellow Ticket:
Does the LL go through a delay box?

No it does not

People have had trouble operating the line lock when driving my car. I have an old (25+ years) Hurst line lock. To operate, you press the button then push the pedal. The brake pedal will stay down on the floor and pop up when the line lock button is released.

I have thought about changing it but refuse to do it, lol.

Each one operates differently.

My buddy bought a truck and it had the line lock on the rear brakes. You push the button and it blocks the rear brake fluid and activates the 3 step. You use the brake pedal to hold the truck for the burnout.

For the OP, do you push the button then hit the brake pedal or pump it up, then hit the button?

Looks like the directions below may want you to push then pump.

quote:

B&M OPERATION
Pressing and holding the launch control push button switch energizes the solenoid valve. When the brake pedal is pushed, hydraulic pressure is applied to all four brakes. When the brake pedal is released, the solenoid valve maintains brake pressure at the wheels that it controls, while brake pressure is released at the other wheels. When the push button is released, the brake pressure that was maintained by the solenoid valve is released and
the vehicle can accelerate.

I read this as energize the solenoid then apply pressure to the brakes.