I decided I would make a bit of effort to document my brake journey hoping it might prove helpful to someone trying to stop their hotrod down the road. This story involves a '32 Ford that was built by the previous owner, and purchased by me last summer. I'm not telling the story to bitch about the purchase. I'm still ecstatic to own a real deal Henry Ford '32 3 window and had anticipated the need to go through some "fixes" and personalization of the car. And, I apologize in advance, because I had no plan to tell this story while I was dealing with the brake issues, so I didn't take a bunch of photos...so it's mostly going to be the written word (and will be a bit long winded, again sorry about that, you can choose to ignore the post if you wish). Starting the story at the end...the brakes work fantastically!! I can easily and predictably lock all 4 tires, find the threshold for optimum stopping and pretty much stand the car on it's nose while exerting a reasonable amount of pedal pressure to do so. All good! Following is what I found along the path to achieve this outcome. When first purchased, I had the car shipped across country and directly to a local hotrod friendly shop for it's mandated provincial inspection. I had never driven the car. The shop inspection identified 3 brake related problems: Firstly, the GM mid 80's S10 rear drums had been previously machined right up to the wear limit so that was a recommended repair, though not mandated. Secondly, the steel brake line that made its way to the right front caliper crossed over at the transmission crossmember and the exhaust pipe was making contact with the brake line. A quick tug and the brake line was moved sufficiently to provide the 1" of necessary clearance. And, thirdly the E-brake was pretty much ineffective, so an adjustment was made so the car had somewhat functional E-brake. The shop gave the car a pass. I left the shop giving them assurance that my intention was to go over every inch of the car and correct anything I find. I loaded the car on my trailer and got the car registered and insured and then headed home pulling my new acquisition. Once home, I unloaded the car and after driving a couple hundred yards, found the brake pedal required excessive pressure with dubious results in slowing the car (it felt like there was a brick under the pedal stopping it from going down). I had a number of things I wanted/needed to repair and change, so brakes were simply another to be added to the list for investigation. The components that I found on the car as built: one of those 7" single diaphragm vacuum brake boosters that are commonly sold to hotrodders. It was mounted under the floor a dual chamber master cylinder from a mid 70's GM truck with 1 - 1/8" bore diameter GM factory style proportioning valve (to me, these are more of a brake balance switch designed to turn on a dash light when one side of the system fails - no light was connected) Early 80's GM Truck or full size car front calipers with 12" rotors S10 rear drums I don't feel there is a need for a power brake booster on a small/light weight hotrod and have not heard a lot of great things about the 7" single diaphragm unit. So it and the attached master cylinder were the first items to land in the dumpster. They were replaced with a dual chambered disc/drum master cylinder for manual brakes from a mid to late 70's Ford Granada/Mercury Monarch/ Comet/Maverick with the .938" bore diameter (Raybestos part # MC36440). I removed the brake pedal while removing the old master cylinder...and found the pedal ratio to be 3:1...yup, I couldn't believe it either. So, with some additional measuring, modifying and re-drilling the pedal ratio was modified to obtain a 6.5:1 ratio. The next item to be dumpster bound was the GM proportioning valve thingy and the brake lines complete with their routing (near the exhaust). Upon the re-do, I included a 2 lb residual valve going to the front brakes, a 10lb residual valve going to the rear drums and an adjustable proportioning valve in the lines to the rear brakes. I used Wilwood components. The rear adjustable valve remains fully open (it's probably unnecessary, but it gives me adjusting options and makes me feel like a hotrod guy because it's there). Speaking of rear brakes...on went the new drums and the rear brakes were adjusted accordingly. I re-routed and re-adjusted the e-brake cables and can report they too are now fully and properly functioning. It was now time to bleed the system. All seemed to bleed well, but I now had the dreaded low pedal (near or at the floor) on first brake application. The pedal would come up and be firm after a pump or two (but who has time for that when the brakes are called into action!). Yup, the front calipers had the dreaded GM low drag design (keeping in mind these were calipers from a full-size GM car/truck, not the mid-size metric caliper). So, rather than mess with the 12" rotors and trying to find a non-low drag version of the full size calipers, I went with and installed a Speedway front brake kit. I've had good success with this kit previously (https://www.speedwaymotors.com/1937...Brake-Kit-5-on-4-3-4-Metric-Caliper,2010.html). After re-bleeding the brakes, I had great pedal. But, the car seemed to rely on the front brakes/wheels for all of it's stopping power. The front tires would lock up, but I had very little sign of braking from the back no matter how hard I pushed the pedal. Still not ideal. About that time, this thread came along (perfect timing): https://www.jalopyjournal.com/forum/threads/drum-brakes-lack-of-stopping-power.1283549/ So, as identified in the thread above, the next 2 items to investigate were the sloppy wheel cylinder that are held on with clips and the worn/rusted GM S10 rear backing plates...and sure enough mine had that issue. Interestingly, the PO had tried to address this by siliconing 2 small pieces of 1/8" thick steel on the sides of each of the wheel cylinders to try and prevent them from rotating. Yeah, I was surprised too! So, the backing plates were replaced with Dorman part #13867 (one for each side). I could have used Dorman part # 924220 which is for the pair of backing plates, but strangely I could buy 2 singles for significantly less $ than the pair. The Dorman backing plates were pretty much twice as thick as the GM factory backing plates...a good problem solver fix. And lastly, the rear wheel cylinders were from a power brake S10 and were a mere 3/4" diameter. They too were upgraded to the manual brake wheel cylinders (Raybestos part #WC370267) which are 7/8" diameter. After yet another re-bleeding, SUCCESS! This is the path and findings I had along the way. I thank many of the HAMB "What's wrong with my brake" threads, as in one way or another many of the threads or those far more knowledgeable than me that contributed with ideas, theories, solutions or recommendations provided me with an investigation path, part numbers, or the answer. I hope this thread might prove helpful to someone in the future. And, lastly a photo of the subject of this story, so there is at least one photo (or it didn't happen).
shows what taking a methodical and logical path thru issues can do, rather than just throwing $$$ at it.
The problem with brakes is that you can't see what is happening when you apply the brakes. Glad you saw the light at the end of the tunnel.
Nice. I am on a similar journey. I’m currently at the stage of having a rock hard pedal with only about 3/4” of travel. New M/C with 1” bore is sitting in the (unheated) garage awaiting better weather for installation. I’m also changing the rear cylinders to the S10 ones to get more rear braking, can currently lock the fronts while the rears are doing little to nothing to help.
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