I installed a new power Master cylinder in my 53 Chevy "Gasser" build. Its a disc to drum unit. I ended up finding and installing an 8.8 Ford rear with discs already set up. Question, what is the difference between a drum/disc vs disc/disc master cylinder? Can I use really just use what I got? Do I need a special proportioning valve? While I'm asking, what is the correct size brake line to use for rear disc? rear drums? front discs? Is there a formula depending on rotor diameter, length of line, etc?
The disc/disc master will have nearly or the the same size fluid reservoirs and no internal residual valve. The drum reservoir is really marginal for a disc axle. Common line size is 3/16" OD for the majority of pass cars/light trucks. Most disc/disc vehicles used proportioning so you may or may not need one. Just make sure you can bottom out the master cylinder before the pedal runs out of travel.
Basically you have more residual pressure on drum brakes than on disc brakes. You really want a proper master. or an older master without built in residual pressure valves.
I converted the rear drums to discs. It was a waste of money. It's better to invest in better front brakes, where most of your braking power is (unless you spend a lot of time driving in reverse). Rear discs, however, can be an improvement on a track car that sees a lot of hard braking, where discs are less likely to fade.
If your master is under the floor you will need Residual Pressure Valves. If it is firewall mounted you should not need them.
As to reservoir and line size a very small amount of fluid actually moves when you apply the brakes. With disks as pads wear more fluids end up staying in the calipers But of you check the fluid at oil changes an small reservoir will be OK.
wanting to put a brake booster and brake cylinder on my truck. The question is, I only have 7" between the firewall and the Carburetor. If I could find the master and booster seven inches from the firewall out, that would work. Has Anyone run into this dilemma?
Bob have you got enough room to fit an under dash system like this. Click on Brake Example then click on 90 Degree https://kugelkomponents.com/
Call Master power and see if the master you have has a 10lb. residule valve in the rear portion. If it does, you will need to change it out. A 10lb. valve would cause brake drag at all times on the rear. Anytime you have a firewall mounted master cylinder, discs normally won't need any residual valve at all. There is no need to run anything other than 3/16" brakeline everywhere. It has adequate volume and pressure loss to be the best choice.
You could use a remote Power booster from a 56 T Bird . JMHO Sorry for the misprint it was a brain fart.
I have mechanical brakes the Master cylinder is all that was installed. The question, if I install a new master cylinder with a proportioning valve would this give me better braking?
I have disc/drum. Wilwood 4piston front and their MC. 8.8 Explorer rear with 11” drums from a F-150. No Booster. Works great. Wilwood has excellent tech. Helped with even the rear wheel cylinders. Best to know you pedal ratio before you call them. They even have 6 piston front calipers.
Your first post led me to believe you had to keep the master cylinder close to the firewall, and not using a booster would help. Now I'm really confused because of the mechanical brakes! You need to clarify your brake system and exactly what you want to do.
@Bob Woods You should start a new thread with your questions rather than hijacking this one. Some of the responses to YOUR questions might confuse the guy that started this one. Mechanical brakes have no master cylinder. Hydraulic brakes do. When you start the new thread, make sure you tell us what kind of brakes you have on the front and rear of your vahicle.
I did start a new thread and did not highjack anything. That is what I don't like about asking a question, you seem to always get a smart a*s
if you look back you did try to take over the original by (tabley)then others started to answer you and ignored the original.happens all the time then they wonder where the hell the ones that could help just shrug their shoulders or have left for other venues sad
At the forum page in the near top right is “post new thread “ in red. That way you create your own topic by itself.
Well, I don't want to be a smart ass, but you did stick the following question right in the middle of this thread. See post #10 above. That's basically what hijacking is. Like @Budget36 said above, to start a new one:
The Jalopy Journal
