My Scout friends came back on Sunday to help me button up the rear drum brakes on Peer Pressure. When last we left off, we’d put new pads and hoses on the front discs but when we pressurized the system one of the rear cylinders blew out under the increased pressure from the hydro-boost. It was getting late, and everyone was tired, so we agreed to meet again to finish it up. In the week following I bought a new set of drums to match the shoes I got with the Scout, as well as a full spring kit and two adjustable valves.
Bennett and Dennis came by in the early afternoon, bundled up for the freakishly cold weather (the day before, it had been sunny in the high 80’s) and we set to work. First we jacked up the rear and put the axle on jack stands. Then we pulled both wheels. I told Dennis I’d never done drums before, only discs, so he sat with me on one side while Bennett had the other side to himself. We pounded and pried off the drum on the driver’s side, mangling one of the clips in the process, and tore down the drum.
Dennis stepped me through the rebuild process patiently until we got to the clip that had been mangled, and then I had to get on the phone to find a new one. Luckily a local parts store had the kit we needed in stock, so we ran out to grab it.
I had inherited a set of brake shoes when I bought the truck, so it was a bit of a toss-up whether they would fit in the drums I got from NAPA. It turned out I needn’t have worried, and they went in without a hitch. Somehow Bennett got his side’s clips, springs, notches and pins aligned correctly and installed before Dennis and I did.
The shoes on the truck were still in excellent shape (as were the drums, actually) but we replaced everything while we had it open. Bennett had to reflare both brake lines because the fittings had rusted to the cylinder, which took time. Then we bled the whole system out, reflared a leaky fitting, and bled it again. At that point everything was holding pressure so Dennis fixed the brake light switch and we opened the barn doors for a test ride.
The difference is immediate and dramatic. The pedal throw is similar but the brakes dig in and hold a lot faster than they ever did before; the whole truck comes to a stop much faster and with purpose while the old system took a lot of frantic stomping and swearing to work. It’s going to take some getting used to, but that’s the kind of progress I like. It’s great to finally have this project completed.
I’m continually amazed and humbled at the generosity and patience of my friends, and I am thankful for their time and expertise. And they’re a lot of fun to hang out with. I really don’t know how I would pursue this hobby without them.
Last night’s cold and gusty weather continued into today, freshly piled leaves cluttering up all the places I’d raked in the rain last weekend. I had guests coming to the ghetto garage, so I tried to church it up as much as possible. Ray arrived from PA early, and stopped to pick up coffee and donuts for me. Bennett arrived soon after, and then Brian, Dennis, Brian H, Carl, and Alan. We stood around and shot the shit for a little while, and then dove into our list.
The Hydroboost unit went in with little fuss, although I can’t take any credit because I wasn’t doing much of the work. Bennett, Ray and Dennis are the subject matter experts, so the rest of us sort of stood around in my crowded little garage and watched as they worked their magic. Bennett pulled the battery, removed the stock brake booster and cleared the lines.
Ray set up the aluminum standoff block and drilled new holes in the Astro mounting plate while Dennis pulled the assembly under the dash apart. Within an hour the main unit was bolted in place and the hoses were run. There was some concern over the hard lines going from the pump to proportioning valve but Bennett showed his skill with a flare tool and had new ones bent and fitted in an hour.
While we had the brake system pulled apart, it made sense to pull the wheels and go through the brakes. However, NAPA failed me on Thursday and did not put my order through for pickup on Friday, so the pads, calipers, cylinders and other parts I’d ordered never arrived. Bennett raided his considerable parts stash and brought a new set of front pads, but when we pulled the front wheels off and looked at the calipers (and banged on them with a hammer) it was clear we would need replacements. I started working the phone, and a different NAPA came through for us. Somewhat stalled, we took a break for lunch at the local diner, and by the time we were done the parts were waiting for us.
Back in the garage the new calipers went on smoothly, and we bled the brake system from the front to the back. A few adjustments to the pedal were made, a legacy vacuum hose to the old booster was plugged, power steering fluid was procured and added, and the truck was idling smoothly with no squealing from the pump. However, Brian noticed the rear passenger brake started leaking heavily, so we shut the truck back down again. Apparently the brake cylinder blew up with the increase in pressure from the pump.
It was 6PM, getting cold, and already dark, so we called it a day at that point. I’ve got a list of parts to buy for the rear brakes–mainly a spring refit kit and two new soft brake lines, because I have shoes and bought cylinders today. We’ll pick up part two in a couple of weeks.
I got a really nice letter from Bennett, one of my local Scout friends, when I was laid up last month. He offered to get our local group of IH guys together and get some work done on Peer Pressure while I was laid up, the generosity of which blew me away. We set up a date in early March and he had me put together a list of stuff I’d like to tackle: Hydroboost, fuel sender, and maybe something else if we have the time.
The Hydroboost project involves removing the big stock brake booster and replacing it with a GM hydraulic unit sourced from an Astro van and hooking it into the power steering pump. What this does is improve overall braking power, allow for added stopping power in the event of an engine shutoff, and make more room in the engine bay. Back in 2013 I assembled all of the parts but stalled out, because I don’t trust myself enough to follow the sparse instructions found online or bleed the brake system correctly by myself.
Clockwise, from upper left: Astro brake unit, power steering hoses, power steering adaptors, aluminum standoff block, brass fittings.
So I’m sending this photo over to Bennett and Ray, the acknowledged experts, to make sure I’ve got everything I need. I’ve got to pick up new brake fluid for sure, but hopefully everything else is correct.
Peer Pressure is squirrelly. Suspension mods installed by the previous owner make the ride stiff; at highway speeds expansion joints and large bumps render the steering vague as the body floats up over the springs and back downward. Braking has gotten dicier since I bought the truck. Moderate pedal pressure these days sends the front and rear in different directions as the pads and calipers grab at different points.
Among the many repairs and upgrades I’d like to do is one of the (I’m told) easiest and most inexpensive improvements to the braking system: the Hydro-Boost. A system originally installed in GM products the world over, it’s an improvement on the old big round booster design Scouts were installed with, because it does away with vacuum-powered braking in favor of fluid power supplied by the power steering pump. It seems to be a pretty popular mod for a lot of vintage cars. Following a thread on the Just Internationals forum, I ventured out to the junkyard with my brother-in-law in search of an Astro Van with ABS brakes. We found four with and two without—the difference being the ones without ABS have the big round brake booster we’re looking to discard. I found an ABS Pontiac Safari already propped up on tires waiting for me, so early this morning I got to work.
I disconnected the hose running across the top, then the right-side hose that ran to the power steering pump. Thankfully, someone had already pulled the radiator, so I had a ton of room to work with.
The left-side hose running down underneath was very difficult to get off (I didn’t have metric wrenches) so I punted and cut the hose as close to the top of the metal line as I could. I used a pair of channel locks to snip the coiled metal hose running to and from the ABS computer (the big box directly below the hydroboost assembly) below the proportioning valve because those bolts were not coming off for love or money.
Finally, I crawled inside and used a long 15mm metric socket to take off four mounting bolts on the bracket. Hopefully other used Astros will be cleaner under the dash than mine was.
Then, a bunch of wrestling, tugging, pulling, and twisting got the whole assembly free. GM didn’t leave a lot of room in the engine bay to work with, so I removed the top fitting to clear the cowl and put it back on when I was done.
Stay tuned. Next I’m going to assemble all the parts needed to retrofit the assembly.