Master cylinder s

[winfield scott]

Hi guys.
What master cylinder are you using for disc/disc applications?
Also how many are using a power assist M/C ?
Brands/suppliers?
Inguiring minds are working overtime!

[Kevin Seward]

Good morning Windy, it has been several years now ( ? about 5 or so) I'm not positive this is the same one I have but it looks similar and I did but it from Speedway. The one I have is all aluminum and is a dual system. It is unpainted because of not if but when you spill brake fluid on it I don't have to worry about the paint. I'm running Disc / Disc on the T and I see this one calls out Disc / Drum. anyway I'm happy with mine except for I have to push harder on the brake pedal than I did with the old one..
Here is the link, https://www.speedwaymotors.com/Aluminum ... 50598.html

Kevin

[winfield scott]

Good morning Windy, it has been several years now ( ? about 5 or so) I'm not positive this is the same one I have but it looks similar and I did but it from Speedway. The one I have is all aluminum and is a dual system. It is unpainted because of not if but when you spill brake fluid on it I don't have to worry about the paint. I'm running Disc / Disc on the T and I see this one calls out Disc / Drum. anyway I'm happy with mine except for I have to push harder on the brake pedal than I did with the old one..
Here is the link, https://www.speedwaymotors.com/Aluminum ... 50598.html

Kevin

Thanks Kevin,
How are your jag brakes, lately I have noticed that the rear brakes are feeling weak. Replaced calipers and rotors, new pads recently.
Maybe the M/C is just getting weak?

[Kevin Seward]

Good morning Windy, it has been several years now ( ? about 5 or so) I'm not positive this is the same one I have but it looks similar and I did but it from Speedway. The one I have is all aluminum and is a dual system. It is unpainted because of not if but when you spill brake fluid on it I don't have to worry about the paint. I'm running Disc / Disc on the T and I see this one calls out Disc / Drum. anyway I'm happy with mine except for I have to push harder on the brake pedal than I did with the old one..
Here is the link, https://www.speedwaymotors.com/Aluminum ... 50598.html

Kevin

Thanks Kevin,
How are your jag brakes, lately I have noticed that the rear brakes are feeling weak. Replaced calipers and rotors, new pads recently.
Maybe the M/C is just getting weak?

Well, Maybe like me it is a factor of just getting older and the legs just aren't what they used to be ??

As I mentioned above I do have to push harder on the brake pedal than I did with the old setup. My old setup had cast iron front calipers GM single piston and fruit jar master cylinder. They worked real good on the front, but I couldn't tell if they really were doing very much on the rear. they were so out of balance that if I did an emergency braking the front wheels would actually lock up and any speed. I only did that one time as a test to see if they would and at about 60 mph I did a hard braking and smoked the front tires for about a quarter of a second.
Now I have switched to Wilwood front calipers and the dual master cylinder and with extra hard braking I on occasion can just barely lock up the rears, but not every time and no longer the fronts. My brakes will now send you through the windshield if you push the pedal hard enough and it doesn't feel like any loss of control, unlike the old setup was.

Are you coning to the lake this year?

[winfield scott]

Good morning Windy, it has been several years now ( ? about 5 or so) I'm not positive this is the same one I have but it looks similar and I did but it from Speedway. The one I have is all aluminum and is a dual system. It is unpainted because of not if but when you spill brake fluid on it I don't have to worry about the paint. I'm running Disc / Disc on the T and I see this one calls out Disc / Drum. anyway I'm happy with mine except for I have to push harder on the brake pedal than I did with the old one..
Here is the link, https://www.speedwaymotors.com/Aluminum ... 50598.html

Kevin

Thanks Kevin,
How are your jag brakes, lately I have noticed that the rear brakes are feeling weak. Replaced calipers and rotors, new pads recently.
Maybe the M/C is just getting weak?

Well, Maybe like me it is a factor of just getting older and the legs just aren't what they used to be ??

As I mentioned above I do have to push harder on the brake pedal than I did with the old setup. My old setup had cast iron front calipers GM single piston and fruit jar master cylinder. They worked real good on the front, but I couldn't tell if they really were doing very much on the rear. they were so out of balance that if I did an emergency braking the front wheels would actually lock up and any speed. I only did that one time as a test to see if they would and at about 60 mph I did a hard braking and smoked the front tires for about a quarter of a second.
Now I have switched to Wilwood front calipers and the dual master cylinder and with extra hard braking I on occasion can just barely lock up the rears, but not every time and no longer the fronts. My brakes will now send you through the windshield if you push the pedal hard enough and it doesn't feel like any loss of control, unlike the old setup was.

Are you coning to the lake this year?

Thanks for the info, sounds like the way mine is acting. All fronts and barely any rears.
No we aren't going to make the lake this year.

[Kevin Seward]

Shoot, always look forward to the 2 of you at an event.

A thought about the weak brakes. I'm going to figure you have bled the air correctly. Not sure, just thinking out loud, but try using a pressure gauge and move it to each caliper and hit the brake for normal feeling amount of foot pedal and see what pressure the gauge shows. I'm guessing you could install an adapter fitting into the bleeder screw hole maybe ?? It won't be easy, but if you can do it you will at least know what pressure is being applied to the pads. Now the good question would be what kind of pressure should the gauge show. What brand of calipers and master cylinder are you running, maybe you can call that manufacturer ??? They might have some diagnosing ideas as well.

How long since you have had good brakes? Let us know how things go and good luck.

[fwestrup]

If you feel that you are having to push harder to stop, check to see what size piston bore you have in the master cylinder and find one with a smaller bore. You will have a little more petal travel not much but you will increase the pressure to the brake calipers. Most cylinders sold have a 1 inch bore which is to large for manual brakes.

[winfield scott]

If you feel that you are having to push harder to stop, check to see what size piston bore you have in the master cylinder and find one with a smaller bore. You will have a little more petal travel not much but you will increase the pressure to the brake calipers. Most cylinders sold have a 1 inch bore which is to large for manual brakes.

Thanks for the tip, running a 1" bore M/C from the start, 130,000 miles plus.
I noticed the difference when I increased my front rotor size from 9" to 11".
I am thinking that the 10.25" jag rotors will not lock up with my 33" tall rears, much bigger than what was on a XJ6 sedan.

I will look for a .875" bore master in the meantime.