When shopping for my first used car as a car-crazy teenager, my dad went with me and warned me by saying, “Son, you can forgive a lot of faults in a car if it starts easy, stops when you want it to and it runs without overheating.”
I told him I was looking for a car, not a wife.
As usual, I found out over the years he was a lot smarter than I gave him credit for at the time when I already knew it all.
Easy starting can be accomplished by a good tuneup, which we can talk about in a later issue. We have already talked about overheating, so by popular demand we’ll talk about brakes.
Of course, those of you who know me realize that we will be referring to 1936 to 1948 LaSalles and Cadillacs. In other words, hydraulic drum brakes with single master cylinders and mechanical parking brake.
We could write a whole book on brake troubleshooting, but for this column, we’ll cover a few of the most common problems.
The first is—no brake pedal. Most obvious is no brake fluid, if you check the fluid in the master cylinder and it is low or empty, the first thing to do is find the leak and correct it. Just follow every brake line and check the back of every wheel. The leak will probably be obvious.
After the leak(s) is/are repaired or defective part replaced, refill the cylinder. Bleed the brakes one at a time, starting with the furthest wheel from the master cylinder and ending with the closest.
If the leak was inside one of the wheels, be sure you clean up the area well.
If your brake pedal is spongy, it is probably an air bubble somewhere in the system. When you bleed your brakes, don’t be stingy with the brake fluid or be lazy—bleed each wheel in the order mentioned earlier, making sure you bleed each wheel until you’re getting clean, new fluid and no bubbles. Discard the fluid you bleed out.
If you have uneven or grabbing brakes on one, two or three wheels, it could be just adjustment, a broken shoe or some other obscure failure, however, 90 percent of the time it is due to dirt or grease in one or more shoes and/or drums.
Then get a couple of cans of brake cleaner spray from your favorite parts store. Liberally clean and wipe the entire brake assembly and drum. This cleaner evaporates quickly and leaves no residue. Be sure you work in a well-ventilated area—this stuff can really smell.
If any wheel has excessive grease, you probably have a seal leaking that needs replaced. Failure to replace the seal will just bring back the problem later. Inspect all parts at this time. If you have brake fluid visible in the mechanism, you have a leaking wheel cylinder. Wheel cylinder rebuild kits are readily available.
Check the linings and drums for grooves and excessive wear. You may need or want to put on new linings and/or turn the drums. Remember that if you do one rear wheel, you must also do the opposite one. The same rule applies to the front wheels.
Brake Service Wholesale here in
Very often, after a real hard panic stop, you will experience somewhat erratic or uneven braking. This is generally caused by one or more linings pulled from the shoe, either fully or partially.
This means that the shoes must be removed and checked. You will need new linings on that wheel and remember, you will also need to replace the shoes on the opposite wheel or you will build in uneven braking.
The master cylinder is the heart of the braking system and is frequently the source of braking problems. On the other hand, it is fairly easy to rebuild or replace. Some of the symptoms of a bad master cylinder are easy to detect. If you hold the brake pedal down and it slowly goes all the way to the floor, it needs a rebuild. If you need to pump the brakes to get good pedal, the same applies.
One of the most mysterious symptoms is when the brake pedal seems to “build up” and/or the brake lights seem to stay on at times. It is usually caused by a piece of dirt blocking the relief port in the cylinder. This is a very small hole in the bottom of the master cylinder caused by dirty brake fluid or one of two other reasons.
The most common cause is in a rebuilt cylinder that has been honed out but not fully cleaned afterwards. Many times, when a new master cylinder has been installed that was NOS or has been on the shelf a long time, corrosion or rust may have blocked this relief port. You will need to clean this port out with a piece of very thin and hard piano wire.
If you are lucky, you can clean this out while still installed on the car by going down through the filler plug. More than likely, however, you will have to remove the cylinder to do this.
Bleeding your brakes and flushing with clean, new fluid should be part of your annual maintenance program, particularly if the car is driven less than 2,000 miles a year.
Speaking about brake fluids, I am frequently asked my opinion about the new silicone fluid. Well—it’s great but! It can only be used in an all-new brake system. It does not mix with conventional brake fluid. You cannot just flush to change over, you must go all new hydraulic components including new lines.
Hopefully, these few hints will help you enjoy your old car in a safer manner so that when you give the command “Whoa Thar!”, the old girl will respond.
Until next month,