Mustang MonthlyHow To Tech Qa
Vintage Tech Advice - June 2013
Beyond the Basics
Cooling System Volume
How much water does the 289 block hold? After draining the radiator in my '66 Mustang, only eight quarts go back in yet the system holds 15 quarts. Does the block really hold seven quarts? When refilling with anti-freeze, should one gallon of straight anti-freeze be added to make a 50/50 solution?
The engine block and cylinder heads hold approximately half of the total cooling system capacity, with the radiator containing the rest. If the system is filled with just water, then you only need to drain the radiator and refill with approximately two gallons (eight quarts) of pure anti-freeze. The other eight quarts of water in the engine will yield close to a 50/50 mix. I loosen the clamp on the heater hose—on the intake manifold just behind the thermostat—to allow pure water to leak out as the radiator is filled with anti-freeze. The leak will allow the addition of all the anti-freeze while pushing out the pure water. Tighten the hose clamp once the anti-freeze has filled the radiator.
Trunk Latch Woes
I have a basic '69 Mustang hardtop. When I tried to open my trunk today, I encountered a problem. It wouldn't open without some semi-violent bonking and twisting of the key. I finally got it to work but when I tried it again with the trunk open, the latch still refuses to unlatch. I removed the latch and took it apart from the lock to clean and lube it. With the extension off the lock, the latch then released fine. I put the latch back on the mount and turned the mechanism with the extension and it worked fine that way too. But when I reinstall the latch and put the extension back in, it won't work. Any ideas why they won't work together? By the way, the extension is slightly bent. Should it be straight?
The extension between the lock cylinder and trunk latch is binding. The bend in the extension is necessary for proper alignment but if the extension shape has changed, a binding condition is created.
Look closely as you operate the lock and watch for the bind at either the lock cylinder or trunk latch. Try operating it with the lock cylinder horseshoe mounting clip removed so the cylinder is loose in the car body to temporarily ease the binding. You can easily reshape the extension with pliers to correct the situation.
I have a '68 Mustang Sprint B with the 302 engine, automatic, and factory power disc brakes up front. When I bought the car, it had been sitting for five years. After getting it running again, I had to address multiple driveability issues, including the brakes. The master cylinder was frozen and the calipers were suspect as well. I have replaced the master cylinder, calipers, brake pads, hoses, and proportioning valve. Now the brakes work great but they drag a little; not enough to make the wheels hot, but enough that it is hard to turn the rotors (with the wheels off) or even push the car. Is that a problem?
Some brake drag can be considered normal, particularly if there are not any heat related issues. Disc brake pistons do not have any type of return spring and rely on the rubber seal inside the caliper to retract the piston. The seal actually twists slightly when the piston moves, thus as the seal relaxes it should pull the piston back.
Be certain you do not have an issue with the hydraulic system that is holding pressure and preventing the brakes from releasing completely. Open the bleeder screw on the wheel that seems to be dragging. If the wheel turns freely, then you have something in the hydraulic system that is creating residual pressure. The master cylinder or proportioning block may have a slight blockage to create residual pressure. This is rare and usually will cause the brakes to overheat, so I doubt that you have this issue.
I'd drive the car and let the brakes “settle in.” I believe the dragging will go away on its own.
Electric Choke Power
I need help with wiring for an electric choke on my Edelbrock carburetor. I am in the middle of switching the alternator from stock to a one-wire from Tuff Stuff Performance. My stock alternator had an “STA” connection. The one-wire version doesn't. My question is: Where do I hook the positive wire for the electric choke? My stereo is already running off the accessory fuse at the fuse box. Please help. My '68 is going to sit in the garage until I can fix this.
Pine Grove, CA
The electric choke can be connected to any power source that is controlled by the ignition switch. The stator connection on the alternator is commonly used because it is hot only when the alternator is operating. The idea is to prevent the choke from opening when the engine is not running. If wired to a key-switched power source, the choke will open as long as the key remains in the “On” position.
If the key is in the “On” position with the engine not running—to listen to the stereo, for example—the choke will heat up and open fully. Only cold starts need the choke, therefore this should be considered if the vehicle is to be operated in this manner.
Let us hear from you. Send your '65-'73 Mustang questions to: Beyond Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. Send email to email@example.com.