I've been lurking off and on for about a year now, but thought others would appreciate it if I shared my solution for brakes on my 1946 Chevy 2 ton dump truck. I rescued this thing from the woods and have now put it back into service. I'll start a "Introduction Thread," after I finish this one! So without further adieu, here's my brake system!
A few pictures to start
https://goo.gl/photos/Bt4DmrgVGejjJspD7https://goo.gl/photos/xRaULcKAYrEAGSm66https://goo.gl/photos/yAsz9RL8pvqURBuR7Album of pictures related to this truck:
https://goo.gl/photos/RZqdb4sSDLedh8Ka6Parts list (Parts for my '46 may or may not fit your truck)
Front Wheel Cylinder: NAPA UP 3406 (1 1/4” bore)
Rear Wheel Cylinder: NAPA UP 3677 (1 1/2” bore)
Soft Brake Line (All 3): NAPA UP 4497 (16.5”, Male 7/16”-20, Female 7/16”-24)
Hard Brake Line: ¼” (Used stainless from Inline Tube)
Master Cylinder Bore Size: 1 ¼” (Same as 1985 Chevy C20)
Booster Size: 7” Single Diaphragm (Speedmaster PCE165.1008)
Brake Return Springs from Jim Carter Truck Parts (Front and rear are the same on 2 ton)
Rear Wheel Seal: SKF 31870
Front Wheel Seal: SKF 20702
2x Wilwood 10# Residual Pressure Valve (DONT GET THE CHEAP ONES)
My main goal was I wanted a cheaper alternative to the factory parts (150+ for a master and 200+ for a booster). The main goal was to mimic the factory system by using the same pedal geometry and hydraulic ratio as the engineers designed it with initially. I got this truck as a non-running, non-stopping hulk so I had no way to know if the system needed to be changed or not either. I also wanted to be able to have a more universal part to do easy parts swapping on if needed (contemplating discs up front in the future). So to keep it in the family and cheap I chose GM parts for the most part.
The master cylinder is from an 85 Chevy C20 with a gas engine. The engine type is important because the diesels and one tons came with hydraboost systems. The masters on gas engined trucks with a vacuum booster had a little bleed bole in the master for the unfortunate incident when the booster diaphragm ruptures it doesn't suck fluid out of the master cylinder past the seals. The reason I chose this master was because it has the same bore (1 1/4") as the factory master cylinder.
On to the booster. I choose the 7" single diaphragm booster because it is roughly the same size as the hydrovac booster that came off the truck. This booster appears to be the same one as Speedway sells, but can be had from Jegs for about a 1/3 the price. It also bolts up to a GM master and as you'll see in pictures and can reuse the clevis that came off the '46 master.
In one of the pictures you will see the key to it all, the offset pivot arm. This arm utilizes the same geometry as the factory bracket, just offsets the input and output planes such that they will both clear the new booster and push on it's input without any interference. The pivot arm bracket utilizes the two factory rivet holes from the old pivot arm and then two new holes below it.
Not pictured is my vacuum hose routing or my brake return spring that I found out I needed after I got it all together (my vacuum check valve was stuck making it feel like I didn't need a return spring...). The vacuum I piped across the truck from the original steel pipe using a chunk of PVC pipe and some vinyl washer hose (harder to crush than rubber). The brake spring is just a small screen door spring from ace that pulls back on the pivot arm, nothing special.
So that's what I have to share! So far it's working pretty good in my truck! I probably won't frequent here, but I'll check in from time to time. Feel free to drop me an email [email]tractorshopATgmailDOTcom[/email] if you have any questions on the system or truck in general.
Happy motoring everyone!
