Re: Larry's 1951 Club Sedan Project

Posted by d c On 2014/7/12 14:21:16

I have read alot of great info on the threads here and want to add a little info on brakes that I have not seen in the prior 2 or3 threads but may have been stated before in threads over the years. It may help some of the hobbyists, back yard warriors and retired mechanics alike. Road test vehicle before disassembly if possible. I cannot emphasize enough, if there is any question as to the condition of the brake "hard lines" (steel brake pipes) replace them all. Use new steel (not stainless) unless you can buy pre flared stainless as the stainless is much more difficult to double flare with out splitting. Do not cut tubing with a pipe or tubing cutter as the wheel rolls and hardens the tube. cut with cutoff wheel and square off with same or a file and clean and flush and DEBUR inside and outter lips and you will see how professional, consistant and leak free they will be. Dont forget to put the fitting on first! Replace the brake hoses always- always in pairs if they are not brand new. Rebuild, have rebuilt or replace all wheel cylinders,master,calipers etc. Shake down entire front end for loose or worn parts and replace as necessary and check tire condition and tire pressure.
Besides all the other good info stated prior on shoes and backing plates such as axle seals,brake fluid contamination,parking brake cable adj, shoe material etc, I would like to bring to light a few other issues I have come across and the problems they may cause. Always disassemble the threaded star adj and lube the socket end and the threaded collar end with wht high temp lubriplate/lith grease and inspect backing plates for rust,grooves,gouges in the contact pads and lube with same. I have seen antisieze dry,harden slightly, and get stickey over time in high heat situations so i use it on bolt threads,not brake parts. It was stated here to not cut drums each time. I agree if they are not scored, heat checked, and there was no pulsation on the initial test drive, dont cut. I have seen thin drums cause warping and pulsation when hot due to the inability to dissipate heat. I have experienced thin drums cause a spongy pedal feel at low speeds to stop and a pulsation while driving due to drum flex. Drums should be measured for discard diameter but before a trip to the part store/machine shop or buying the drum caliper on ebay, visually check the lip of the drum for thickness and the remnants of the lead in chamfer. Then, take the new primary shoe and lay it in the drum with the new lining in contact with the drum. If it is hitting on a small spot in the middle of the shoe and can be rocked dramatically from end to end ie the arc of shoe way off from arc of drum this is an indication the drum has had too many cuts, This can cause shoe chatter, noise,squeal, hard pedal/reduced braking with cut drums, or grabbing/lock up at low speeds with bedded drums before the shoes are broken in. It can cause the shoe lining to crack or separate from the core on hard brake apply before they are bedded in and worn to the drum. If this is the case replace drums with new if available or take a new shoe with you and lay it in a drum if purchasing used. Adjust and bed in new brake jobs properly. Inspect and repl if nec all springs and hardware. It will be valuable if we have any new replacement drums and hardware and misc brake parts in the xref. I have had brand new drums out of the box warp after the first few heat cycles so I believe seasoned parts if not cut past spec are the best but if new are necessary this is not an area to skimp on. Shoes used to be ground to index to the drums however in this area I do not know of anyone who will do it for the last 10 years or more.I would hate to be in that shop breathing the air. Even on your cloths if wearing a respirator! In contrast to other opinions, I was informed to perform several medium to hard stops from 45 to almost 0 safety permitting of course followed by driving time above 25 sufficient to cool then repeated again if nec until bedded and good pedal feel. You do not want to overheat new brakes as this may cause the binding resins and glues to separate and migrate to the surface causing issues.and lets not forget wheel bearing adj and grease seals.