Tech Q&A - Chassis - BrakesANTI-RATTLER SPRINGS
I just bought some replacement brake retractor (anti-rattler) springs but, unlike the ones I'm replacing, they seem to be curved too much at the ends (almost a W shape). The extra bends make the spring hang at an angle than doesn't allow the concave socket to engage the knob on the brake rod. It misses by about two inches. It looks like a defective spring compared to the old one but my supplier says that's the only kind he's ever stocked. Am I doing something wrong or should I try another supplier? -- Court Saunders
I would try Bratton's Antique Auto Parts. You will find that if there is a quality part made, Walt Bratton has it. 1-800-2551929. It is very important that these retracting springs fit correctly and slide on the brake rod with out hanging up on the return action. -- Les Andrews, Technical Director
I need to remove one rear drum from the hub and replace with a different drum. I believe these were originally sweated on, how do I get them apart and how hot must I heat the new drum?
I am not familiar with heating the hub to remove it from the drum. I recommend using a hydraulic press. You must first remove the lug studs and then the hub. Caution be sure to support the hub around each stud as you press it out or you will bend the drum. If you try the heat method and are successful PLEASE let me know so I can spread the word. I would contact your local Brake and Clutch Shop and see what they have to say. I have my local shop swedge my hubs and studs back in for me after I have pressed them out. -- Lyle Meek, Technical Director
Would you please be so kind as to direct me to a shop where I can send my drums and shoes to be arched together so there is maximum contact of the shoe surface and the drum. I recently had a brake job done and I am displeased with the rapid fading, and upon inspection, the minimal contact of the drum and shoe. -- Gary M. Wheeler
I'm glad you asked the question because so many people overlook the importance of arching the shoes to the drums. That's because brake shoe arching machines were outlawed at least 10 years ago because of the asbestos dust. In most states, only the very large companies that make brakes and clutches can afford the environmental machinery to arch the shoes. I live about 45 miles from Sacramento California. There is a company called Sacramento Brake and Clutch and they manufacture brake shoes and clutches. We take our drums and shoes to them for arching. You will probably have to go to a large city yellow pages and look for a Brake and Clutch company. Your local Brake shop may be able to give you some leads. The Model A drums were 11" and can only be turned a maximum of .060. I hope you find your drums acceptable. You should also make sure your shoes are centered on the backing plates. This procedure is explained in most Model A books that explain about doing a Brake job.
In Schild's Shop Manual, it says that if your drums are worn to their maximum that you may have to 'shim' your shoes. I've seen that Bratton's sell an oversize lining (but only 1/16" over) but have never heard of shimming the brake shoes. Any idea how to go about this?
Your life and the dependability of your car depend on your brakes. If the wear on your drums are very much more than .060 oversize, the drums are too thin and will probably fade when you most need them. The oversize linings are 1/16" over, which is .0625 and could be used with a .060 oversize drum. I would first have your drums checked (measured) at automotive machine shop. Original drums are 11". By law you can not have brake drums turned more than .060 ". If your drums are more than .070 over they will begin fading because of the heat on the drums. The drums will be to thin and cannot dissipate the heat. Many Model A's today have .100 wear on the drums. It's a very risky way to drive. Please check it out and replace your drums if necessary.
Also, be sure to have your shoes arced to the drums when you replace the shoe linings. This will assure full contact with the drum. If you do not arc the shoe linings to the drum you can only expect about 20% to 40% shoe contact to the drum.
Question: I am in the process of rebuilding my brake system. Both the front and rear roller track assembly are in need of replacement or welding to bring them level and smooth. My question is should I choose to weld them should this be done while attached to the backing plate or should I remove them? Also, should I decide to replace them with new ones, as I understand it the new ones are secured with hot rivets; how is this done and do you have a suggested reading material on this process?
Answer: If you plan to weld or braze the tracks it can be done while they are still on the backing plate. A die grinding wheel can be used to grind the weld level. When you replace them, the rivets come with the kit and all you have to do is heat the end of the spring rivet, insert it and peen it over with a hammer. -- Lyle Meek, Technical Director