Mustang 5.0 Stocker brake pressure
 

I got the UPR race products manual kit but can't hold the car on the line past 2000 rpms. I bought some good brake pads for the front and still use drums in the back. Not helping and this is a 5000+ stall converter. My old 3000 stall used to hold at 2200 no problem (with power booster). I bled the system and have a very good pedal. Auto, not a stick.

I plan to put a pressure gauge on this week, how many pounds should I be looking for? Could new master cylinder be the culprit?

Re: Mustang 5.0 Stocker brake pressure
 

Move the pivot up on the pedal where the master cylinder hooks 3/4" and it will hold. Same problem with mine

Re: Mustang 5.0 Stocker brake pressure
 

A bit off topic, but how was the UPR kit to install?

Re: Mustang 5.0 Stocker brake pressure
 

Thanks Lee. The UPR kit was not too bad but definitely not 45 minutes for someone like me. The challenging part was figuring out a line lock schematic because the master cylinders were very different. One had two ports and the other had 3.

Re: Mustang 5.0 Stocker brake pressure
 

How big is the master cylinder bore? If it's 1-1/8" like a lot of those kits, that's way too big for the factory brakes, something like 7/8"-15/16" normally works well.

Re: Mustang 5.0 Stocker brake pressure
 

Yea I think it is larger.. Crapp

Re: Mustang 5.0 Stocker brake pressure
 

Measure your brake pedal. That will tell you your pedal ratio. Then go to any brak mfg website and check their master cylinder chart and it will tell you exactly what size MC to use. If your not sure how to measure it. I can walk you through it, it's not hard. Let me know.

Re: Mustang 5.0 Stocker brake pressure
 

I have a chart somewhere. I just can't remember where I put it. There's actually 2 charts one for a foot brake and one for a hand brake. Chassis shops can tell you. http://www.mpbrakes.com/techtalk/how...ng-pedal-ratio

Re: Mustang 5.0 Stocker brake pressure
 

Thanks for your help. Ok according to the measurement I am at about 4:1 in the pedal ratio. Will adjusting this make up for too large of a master cylinder?

Re: Mustang 5.0 Stocker brake pressure
 

Yes moving it will change your brake line pressure. Usually a 5:1 pedal ratio equates to 1000lbs of pressure with a .750 MC

Re: Mustang 5.0 Stocker brake pressure
 

www.wallaceracing.com/brake-master-cyl-calc1.php
The website above let's you calculate pedal ratio, you put in your info and it tells you brake line pressure.

Re: Mustang 5.0 Stocker brake pressure
 

When you put your info in. It'll ask you your pedal pressure, there are 2 of them, one for your foot and one for a hand brake. It's 150lbs pedal pressure for your foot, and 75 lbs for a hand brake. Ok?

Re: Mustang 5.0 Stocker brake pressure
 

Remember 1000lbs of brake line pressure is ideal, around 1200lbs under hard braking. When I build brake pedals, I shoot for a 5:1 ratio and a .750 MC works out to 1000lbs. It sounds complicated but its really not. Just shorten the distance from the pivot hole to the pushrod hole. If yours measure 3" and your pedal measures 10" that's your 3:1 ratio. All you have to do is drill a hole1" closer to the pushrod. So the distance is 2" instead of 3" that will change your pedal ratio to 5:1 and you can use a .750 MC. Ok?

Re: Mustang 5.0 Stocker brake pressure
 

I am embarrased to say that I have spent the better part of 6 years trying to sort out brake problems on my 3rd Gen Camaro. I started with stock front discs, Wilwood rear discs, and a manual master cylinder from an early 90's S10 pick-up. This didnt work. I then went to Wilwood front discs and a Wilwood master cylinder. I figured since all the components were compatible, I would be all set. Wrong! I then went back to stock front discs, with the Wilwood rear discs, and a 1.032 dia. Strange master cylinder. It worked okay, but I still could not hold the car at line line at anything over 2500. The problen turned out to be pedal ratio and firewall flex. Remember that these cars never came with manual brakes, so the pedal ratio is wrong. I only had about a 4.1 ratio. I redrilled a hole on the pedal and now have about 5.5.1. I also added a simple brace to support the master cylinder, as firewall are very flimsy on these later model cars. I will try to upload a picture.

Re: Mustang 5.0 Stocker brake pressure
 

1.125 master cylinder.. general consensus seems to be pedal ratio so lemme at it!

Re: Mustang 5.0 Stocker brake pressure
 

Probably getting harder to find now, but when I was building my 85 Mustang, I found a stock 4 banger early Fox Mustang with manual brakes, and removed the factory brake pedal, aluminum master cylinder and mounting plate, along with the longer lines from the master cylinder to the distribution valve, and it has been working great for over 10 years now. I got my manual steering rack the same way.I just let the Ford engineers do the calculations.

Re: Mustang 5.0 Stocker brake pressure
 

I used a mid 80s Ford Ranger master cylinder, 15/16" ,and a modified brake pedal from Baer ,with a pushrod that is slightly curved. what is nice about the ranger master cylinder, the lines are on the fender side, instead of being in the way.

Re: Mustang 5.0 Stocker brake pressure
 

Bobby, I think your dad has my caliper pressure gauge (plus my valve spring tester for that matter - lol ) - have you checked pressure?

Re: Mustang 5.0 Stocker brake pressure
 

Redrill your brake pedal so your pedal ratio is 5:1 put a .750 MC on it and you'll have right at 10000lbs. Brake line pressure

Re: Mustang 5.0 Stocker brake pressure
 

My master cylinder support. Once I had the pedal ratio squared away, the firewall was not happy with the new found pedal pressure. Hey even the COPO's need a master cylinder brace.

Re: Mustang 5.0 Stocker brake pressure
 

my little 5 foot 1 inch beautiful bride Beth pumps hers up to 800 psi on the starting line before engaging the two step and that's with her itty bitty size 6 feet
bobby we have some much better pads for you. same as what we put on Beth's car

Re: Mustang 5.0 Stocker brake pressure
 

600lb up front after pumping the hell out of it. Gonna try smaller master cylinder before I start trying to take this brake pedal apart.

Re: Mustang 5.0 Stocker brake pressure
 

Bobby,

I used maximum motorsports manual brake conversion kit ($199 List price) with all stock components on my Super Stocker, brakes just fine and I foot brake it too sometimes. Brake pressures (just went out to garage to check) easy push on pedal 600-800 psi, med push 1200-1400 big push 1700psi+. I love the quality of the components and Its a nice textured pedal.
Here's a link below. I syringe bleed the master backward to remove all air. Stock front t brakes, 10" ranger rears.

http://www.maximummotorsports.com/Mu...ions-C244.aspx

Re: Mustang 5.0 Stocker brake pressure
 

Ok thank you for the tip. Getting the brake pedal out was a nightmare so I stopped and put it back in and decided to get a Ford Ranger master cylinder to see if that can get me to at least 800psi. If that doesn't work then I will look into that new pedal kit from MMS.

Re: Mustang 5.0 Stocker brake pressure
 

Ok got the car running again and installed the MMS brake pedal kit with better ratio so I can hold around 2300rpms on the line as opposed to the 1800 before. This is with the '86 ranger master cylinder. When I try the two step any higher than 2300 it creeps through the beam. My lights suck and I have 20lbs of air in the bias ply slicks. Need to raise launch rpm to reel the RT in. Turning 1.60-1.62 sixty foot times when not creeping. In order to hold better on the line, should I upgrade the back to a disc setup from the drum setup or should I upgrade the front to a bigger/better disc setup than the current stock configuration?

Re: Mustang 5.0 Stocker brake pressure
 

How low is the first gear in your trans and what about rear-end ratio?

A really low first gear ratio can cause the lower stall rpm.

Re: Mustang 5.0 Stocker brake pressure
 

2.92 and 4.88 with 28" goodyear slick

Re: Mustang 5.0 Stocker brake pressure
 

Bobby,

I have stock 89 brakes in front and 10" ranger brakes in the rear. Works great w/footbrake with that MM manual brake kit and stock master.