Home Built C5 Corvette Line Lock
So, with the newfound power in my Corvette, I found that a line lock would be quite useful at the track. Brake burnouts are easy enough, but not consistent and hard on the brakes themselves. Sure, Cartek makes a great line lock kit, but at $250 it's a bit pricey for what's actually included in the kit. No knock against Cartek, it's simple capitalism at it's finest, but I knew for a fact that I could do the kit myself for much cheaper.
So what's needed??? The C5 Brake system is a conundrum thanks to GM. For some reason, GM felt it necessary to get metric with the lines and adapters. Yup, good old GM backwardsness there. The lines are 6mm and the line fittings at the Master Cylinder, Proportioning/Active Handling Valve, and ABS Unit are all M12x1.0 fittings for metric bubble flares. Not common items. But, with some research, I came across a company called Fed Hill that had almost all of the non-standard metric to domestic parts needed.
Here's the parts list:
2 x M8-4 (Fed Hill) -- This is the 1/4" line M12x1.0 metric adapter. These are needed for connecting the new lines to the Proportioning Valve and ABS Unit. -- $4.50 each
2 x A2L-4 (Fed Hill) - A2-4 would work fine too -- This is a standard 7/16 x 24 1/4" line adapter fitting. These are needed to connect the new lines to the Line Lock Solenoid. -- $1.70 each ($1.20 for A2-4)
2 x 202x4x4 (Napa) -- This is a 1/4" line 7/16x24 female to 1/8 NPT male adapter for connection to the line lock Solenoid -- $1.50 each
6 Feet of 1/4" Brake Line -- If you're new to bending, you'll blow through this. I ended up buying a 25' roll from Auto Zone for $8.00 (I work there part time, got a discount, normally $10.99).
1 x SUM-760002 -- This is Summit Racing's Line Lock Solenoid. It's a nice piece, and very nicely priced at $39.95.
1 x PL SW22R (Auto Zone) -- This is the LED Rocker Switch that Beer99C5 supplied with my Alky Control Panel. Costs $5.99 @ Auto Zone or other local retailers.
1 x 12" by 12" sheet of 1/8" thick aluminum -- Paid $8.00 for this at the local welders joint.
12' of 16 gauge black and red wiring -- shouldn't cost more than $5.00 for all of it.
3 x Female electrical spade connecters -- Pennies (I have excess of these for other wiring projects)
1 x Ring Electrical Terminal
2 x Weatherseal 14-16 gauge crimp/heat connecters -- About $3.00 for a pack of 5 at Auto Zone.
Convoluted Tubing -- A random size package is about $2.00 at Lowes.
Here's the meat of the parts.
So, where to begin??? I started things off by fabbing up the mounting plate for the line lock solenoid. Follow the pictures below as I explain what I did.
First, I made a cardboard cutout of a preliminary design I thought would suffice. Given available space, it was decided that the solenoid would be mounted horizontally with the bottom sitting towards the motor, underneath and to the car centerline from the master cylinder. I cut and trimmed the cardboard until it would clear the master cylinder yet mount to both of the master cylinder mounting bolts. Then, using pressure on the cardboard at the bolts, I marked and then opened the holes for the bolts. This was my starting template.
Using the cardboard template, I moved to a bit more sturdy template. I had a small sheet of 16 gauge steel laying around, so I created a more permanent template out of that and refined the shape a little more. Once I'd gotten this piece to where I wanted, it was time to make a piece for real.
Here is the semi-finished piece. I made some additional angled cuts to smooth things out a little more and though not seen here, I polished it somewhat to make it look halfway decent. It fits like a champ right where it needs to be. The noteworthy thing about how I made this is that I don't have a lathe or anything; this was made using a dremel, a drill, and a jigsaw.
Mounting the line lock itself was easy. Center it on the bracket, mark and drill the two bolt holes, nut and bolt the solenoid to the bracket. Above you can see how it's installed and how much clearance is around it. Some may think that it's too close to the engine, but there's quite a bit more area separating the two than the pics show.
Now that the solenoid is mounted, it's time to have some real fun. Time to bed some 1/4" brake line!
There are two spots to run the lines on my car, others may be different. These are from the Master Cylinder (rear line) to the Proportioning Valve (front outside line) or from the Proportioning Valve (Front inside line) to the ABS Unit (Top Left line). Given that my cars washer reservoir is full of M1 Methanol, I decided to put my solenoid in the latter of the line options; from the proportioning valve to the ABS unit.
And here's the newly bend brake lines. The first two pics show the new lines themselves, and the second two compare them to the single line they are replacing. Some things to remember when bending the brake lines: Take it slow, don't bend too fast otherwise you run the risk of kinking a line. Bend a little, check, bend a little more. For your final bend, take it just a tad farther than what you want because the line will spring back some.
As for the flaring........GM uses Bubble Flares. A bubble flaring tool is NOT a common item I've found. My solution to this was to use the Inverted flaring tool, and stop about halfway through the crush process thus mimicking a bubble flare quite closely. I then sanded smooth any ridges and it seemed to work fine as I've got no leaks. You need to do this for the ends of each line that go to the Proportioning Valve and ABS Unit. As for the other ends, a standard Inverted Flare is what you want. DO NOT FORGET to put your fittings on the line FIRST prior to flaring.
Now install your lines. The proper sequencing for the flares and adapters is as follows below:
ABS Unit -- Bubble Flare -- M12x1.0 Adapter -- line -- 7/16x24 adapter -- inverted flare -- 7/16x24 to 1/8 NPT adapter -- LL Solenoid.....................Reverse the order for going to the Proportioning Valve.
And here's the Line Lock with all the lines installed. You can see how the lines route now that everything is in. I didn't do any measuring here, simply eyeballed and bent and eyeballed some more. This part actually came together pretty nicely I think considering this was my first experience bending and flaring brake lines.
Now that the hard parts are installed, it's time for the electrics!!!!
The electrical portion of the installation is very straight forward. You need power and ground and the switch to operate things. Ground is easily taken care of as shown above. As for the power.....
The switch needs to be hooked up through a switched 12V power source. Fortunately on C5's 97-03, there is a plug with three open ended wires for just such usage under the footwell on the passenger side as seen above. I tapped this for the switched 12V power and for the ground for the switch so that the LED would light up letting me know the Line Lock is armed. You'll notice that the wires are just above and to the left of the PCM.
I am going to apologize up front about the lack of pictures for this part, but there's not a lot to be seen.
The wiring itself is quite straight forward. From the accessory wires under the passengers side of the dash, run the switched 12V wire (the orange one IIRC) to the line lock switch input, then take the output from the switch and run it under the dash through the firewall to the red wire on the line lock solenoid. I had wires coming through on the drivers side so I went through there. The run a wire from the black accessory wire under the passenger side of the dash to the ground terminal on the arming switch if it's equipped with an LED alert light.
When setting the wires up for connection to the switch, note that the terminals are very close to each other. To keep them from grounding out on each other, I used heat shrink tubing around then entire teminal as shown above.
So the wiring looks like the following:
Line-------Ground
Lock---------splice to your wiring----------firewall-----------Switch-----------accessory wire under passenger side of dash
\--------ground for LED in switch
That's it. Put the car back together, BLEED YOUR BRAKES, and enjoy!!!
If you're not up to it, I can replicate any component of this kit, just let me know and I'll be happy to help out. If you're close to the St. Louis area and want I can even do a full build and installation for you, just let me know.
Money Invested -- <$75.00
Time Invested -- 4-5 hours
Knowing you did it yourself without paying a hefty Corvette Tax.........Priceless!
Here's my switch panel, replaces the factory ash tray area. Made my Beer99C5 from the Corvette Forum and LS1Tech, and I highly recommend his work.