Brake Guru's...Need a Bit Of Advice.

[bnickel]

if that's the cobra automotive MC it probably won't work for his needs since the plumbing exits on the passenger side of the master instead of the driver side like it did stock. this MC will work great with a 302, but for us windsor guys that have headers it won't since most windsor headers have a tube that goes up and over the other tubes and comes down at the back of the engine and that tube sits exactly where the brake lines from cobra kit MC exit and turn down. needless to say it's not exactly in a good place.

i'm not 100% sure if dolfan's headers are like mine or not but i'm pretty sure his beautiful fab'd alloy valve covers will be another obstruction in there as well.

still though, it could be an option for him or others who don't headers like mine, i have the hedman shorties, but have seen a few other headers designed the same way.

 

[dolfan87]

if that's the cobra automotive MC it probably won't work for his needs since the plumbing exits on the passenger side of the master instead of the driver side like it did stock. this MC will work great with a 302, but for us windsor guys that have headers it won't since most windsor headers have a tube that goes up and over the other tubes and comes down at the back of the engine and that tube sits exactly where the brake lines from cobra kit MC exit and turn down. needless to say it's not exactly in a good place.

i'm not 100% sure if dolfan's headers are like mine or not but i'm pretty sure his beautiful fab'd alloy valve covers will be another obstruction in there as well.

still though, it could be an option for him or others who don't headers like mine, i have the hedman shorties, but have seen a few other headers designed the same way.

Bryan knows my car well.

Those headers actually HIT my valve covers, and we had to do some...ahem...'creative manuvering' of that one header tube to get it to clear. I actually have a brake line within an inch and a half from that header tube. I wrapped the line with heat shield, and my headers are coated, so hopefully we don't have boiling of the fluid.

I have tried the plastic res master, and the thing was actually to long.

I am going to look into the F250 one, and see how long it is.

Thanks guys!

 

[bnickel]

i'll see if i can over to the parts store i used to work for sometime today and see if they have a couple i can compare or better yet grab one of the old bendix spec books and see what else might work as well.

 

[streetgrande69]

how does the system act with the car running?

yes you need a different master. the residuals are behind the brass inserts that the line flairs mate with. problem is, to remove them alot of the time you destroy the insert.
the one that came with your baer kit is a smaller diameter the the stock set-up. just remember that with increased bore comes increased pedal effort. smaller bore, less effort, pressure builds quicker but volume is comprimised.
we should find out what the 00-04 cobras and mach1's are running and match your mastercylinder bore size to that because that's the caliper you have out front. that would get you in the bALL PARK FOR bore size. then go from there. i will be doing this also because my set-up is identical to yours except for the valve, i have an adjustable(i hate it too, don't get me started on that).

remember bore isn't the only factor in line pressure, its also spring rate and stroke distance also. i don't know how to determine the stroke of the front piston without disassembling and spring rate makes my head hurt.....

 

[bnickel]

ok i went and checked one of the f-250 mc's out. the bore is 1-1/4" the overall length is about 1/2" to 5/8" longer than the stock mustang power disc mc. the bolt holes on the flange are the same but the snout for the piston is about 1/16" bigger in outside diameter however i think it will work in the stock power bosster with little or modification to the outside diameter. also the depth of the piston for the pushrod is pretty damn close to the same.

so with a bigger bore and a slightly longer stroke you should have more than enough volume for those brakes.

if you try it out and it works well let me know as i'll probably use the same one whenever i get around to doing my big brake conversion front and rear, which will probably end being a 12" rotor up front with a big lincoln 4 piston k-h caliper and the back getting an explorer/crown vic style rotor/parking drum combo with the smaller 67 mustang k-h 4 piston caliper. should be interesting to build once i can actually get all the parts and pieces collected for it.

 

[dolfan87]

ok i went and checked one of the f-250 mc's out. the bore is 1-1/4" the overall length is about 1/2" to 5/8" longer than the stock mustang power disc mc. the bolt holes on the flange are the same but the snout for the piston is about 1/16" bigger in outside diameter however i think it will work in the stock power bosster with little or modification to the outside diameter. also the depth of the piston for the pushrod is pretty damn close to the same.

so with a bigger bore and a slightly longer stroke you should have more than enough volume for those brakes.

if you try it out and it works well let me know as i'll probably use the same one whenever i get around to doing my big brake conversion front and rear, which will probably end being a 12" rotor up front with a big lincoln 4 piston k-h caliper and the back getting an explorer/crown vic style rotor/parking drum combo with the smaller 67 mustang k-h 4 piston caliper. should be interesting to build once i can actually get all the parts and pieces collected for it.

Ok I will try it. Honestly 1/2" may be more than I can get on there. It is THAT tight.

But I will try it, and let you know.

69- I haven't actually ran the car with the booster hooked up. I need to try that next, but I just didn't like the feel of the pedal with the car off. It was way to easy to push down.

I will get a lot of this done within the next few days and get back on here.

Peace.

 

[DarkBuddha]

I thought I'd post this link to a page on Ultrastang's site: http://www.ultrastang.com/Ultrainfo.asp?Page_ID=15

It shows some details about the installation of a Mark VII master and a 2.3 Fox body Mustang booster. It seems to fit fine for him, but I'm dead positive that the booster isn't anywhere close to as wide as our stock '70 boosters. Hmm... maybe a reason to do another custom trick...

 

[bnickel]

hey Gram, just so you should know the pedal on an early stang doesn't generally feel as tight or stiff as newer car with a more modern booster, they always seem a bit spongy with the car off but once you start it up it has a completely different feel to it. so before you get to far into switching stuff around go ahead and hook up the booster and see if that changes the feel for you. chances are you're going to need a master with a bit more volume anyway, but that may not be the way it works out, the master will need to come off no matter what because of the residual valve anyway, but i'd still check it with the boost hooked up.

what SG69 said about the pedal pressure being higher with a bigger bore is another good point to consider, but personally i like it to need a bit more foot on the pedal, i don't really like brakes that are too touchy because it can upset the car in hard turns if you have to get on the brakes if they are touchy like that.

 

[dolfan87]

I thought I'd post this link to a page on Ultrastang's site: http://www.ultrastang.com/Ultrainfo.asp?Page_ID=15

It shows some details about the installation of a Mark VII master and a 2.3 Fox body Mustang booster. It seems to fit fine for him, but I'm dead positive that the booster isn't anywhere close to as wide as our stock '70 boosters. Hmm... maybe a reason to do another custom trick...

That is a great write up, and would of worked for me EXCEPT...I have a hydraulic clutch. The Clutch master cylinder is right next to my current brake booster, and will not work with a larger diameter booster.

Ahhh the life of a custom car builder...ARRRRRg.

I am going to take Bryan's advice and hook the thing up, start the car, and see how it feels.

I will post results later in the day, cause if I start that engine now, I won't have a single friend in my neighborhood.

Peace.

 

[bnickel]

hey Gram, any updates? just curious if you got it working

 

[Swede958]

gram, I think what DB was saying, and I'm pretty sure I can corroborate it, is that the late model 4cyl booster is smaller in diameter than the stock 70 one. I believe it is only about 7" in diamter compared to I think 8 or 9. I've heard of this, I think from ultrastang's site and from others. This is one of the mods I have been thinking of for my brakes as well ( 12" baers here, rear disks to come later).

Personally I might think about getting rid of the proportioning valve and just run the fronts straight. I ran the fronts straight from the Baer MC (which is a 94/95 mustang peice) with some simple curved line right under the MC. Looks pretty good to me. When disks go in the back I'll redo the lines to their final position along with an adjustable valve for the rear.

THe Swede