manual brakes

[Bert]

I quite like the idea of better brake sensitivity (same as my experience with manual steering). At the moment, when the engine is off (broken timing belt or in the case of 3 weeks ago, the dizzie pickup failed) while rolling at speed the brake pedal is alarmingly difficult to press hard enough on to comfortably stop the car. Is this a function of the inert booster suddenly working against you or this your idea of sensitive brakes?

[getnpsi]

Complete manual brakes is not the same as a not working booster experience. As stated above to make a manual system with available parts you still have to get the geometry stright. With a solid piece to take up the slack its stiff all the way at the top, not smoosh and grab halfway down wide eyed and white knuckled.

[georgeb]

Extreme.

[Christ]

The booster, when not under vaccuum, attempts to compress it's local atmosphere through the hose into the intake, and in some cases, through a (very restrictive) check valve. Given that the booster is 10" or so diameter, and there's about 1.5" (I'm guessing) between the diaphragm and the face of the booster casing, there's quite a large volume (comparatively) that needs to be "moved" while you're attempting to brake when there's no vacuum. So you're fighting not only the pressure of brake application, but the spring inside the booster that's meant to return it to neutral, as well as the "spring" force of the air volume you're trying to compress.

[Safety Guy]

I'm interested in this mod too, if it can be done safely and especially if pedal feel will improve a touch.

My '76 Chevette did not have power assist brakes and it worked just fine. Well, the solid front discs weren't the greatest, and I don't think my rear drums did much, but the rest of the system worked fine.

Karl

[getnpsi]

At my old job the old toyota long bed with manual brakes worked OK, but this was in a tired truck with bad suspension and always wood panel loads. I'm sure the owner replaced pads in a 3x1 ratio with rotors.

I like how this discussion went, I dont think our cars have much issue with its power boosters and the parts are so cheap if someting does go bad but one extra step in a "set it and forget it" still appeals to me. You also free up some more space at the firewall for braided fuel lines and regulator

[Christ]

IF you can find the VW thread I had while I was fixing up the Golf (on Ecomodder), there are probably pics in there of the disassembled booster from it... as well as how I jury-rigged the adapter plate for it.

I've got part of a day to myself tomorrow, I guess... so I might drag the tools down in the yard and see about getting everything apart.

[Christ]

I went through some of my parts and :doh: I had a loose one laying in the bin...

It's supposed to rain here the next couple days, so I'll work on that while I can't do anything outside, including a step-by-step to disassemble one to components without breaking it.

[Christ]

Manual brake swap how-to

This is the brake pedal side of the booster after it's removed from the vehicle. You'll see, around the edges, that there are "dents" which hold the two halves in place. If you look closely, there will be an arrow and the word "loosen". This is there in case you want to rebuild the assembly without forcing it apart. Our intention is not that, however.


Here the halves are split. I DIDN'T USE THE BIGGER HAMMER AND SCREWDRIVER LIKE A CHISEL, AND YOU SHOULDN'T EITHER. IT'S DANGEROUS! The smaller hammer is my Festiva hammer. No joke. Anyway, flatten out the dents that hold the two halves together however you like, then gently pry the halves apart. Careful, don't be surprised when the big spring forces them apart as soon as the rubber breaks it's seal on the metal.





Locate this clip and push it out with your non-chisel screwdriver. It's just got a spring clip holding it in, you can almost push it out with your fingers.



Once you've pulled that clip back, stick your non-chisel screwdriver into the brake pedal pin hole and pull. That's the part you need for the manual brake mod. Remove the push-in retaining ring, the two foams and the felt. When you get those off, flip it over and notice the swiveling part at the bottom. You'll see that it's been swaged onto the ball end. Drill out the swage marks, being careful not to drill into the ball end or shaft. Nicks are OK. Once that swivel end is off, remove the remaining springs and rubber seal.

The rest of the disassembly pics:



Pictured here is the piece you need to be working on. Also, note the swage on the right side of the rod. It's a little dent in the swivel end. There are 3 total.



Exploded view. This is about as far apart as you can get it without damaging anything thus far.



When all's said and done, this is what you should be left with. This piece will attach to the brake pedal and slide into the back of the master cylinder to actuate the piston. You may need to smooth the shaft down (remove the ring) with a grinder, I haven't test fitted it to a loose M/C yet.

[jason_]

I'm curious how this turned out if it was finished/tested?

Sent from my rooted HTC Supersonic using Tapatalk 2 Pro

[sketchman]

X2

I'm itching to try it.

[Festevil3]

you can probably use a mustang manual brake set up, there was a wilwood master on the festicle (which i believe was from a mustang) so if that fit im sure you could use the fox body manual brake stuff.

[sketchman]

^How does that feel? Info on the MC? Say you were in stop and go traffic or hard braking into a corner. Would you rather have your current setup or vac assist?

[MiltonHavoc]

^ x2

[sketchman]

Wait a minute. There is a booster in that pic with a vac line hooked to it. Am I missing something?