[finkster]

1963 Ranchero V8 / 4 Speed
Granada swap front disc set up. No proportioning valve.
I've converted the master cylinder to a dual resevoir style unit with no isuue until recently. I'm not getting a good return on the master and it's keeping the front calipers "engaged". Is it just the master cylinder going bad? Could bleeding the system help maybe? If I need to throw another unit on it, what would you suggest as far as bore size?
Thanx in advance!
Mike

 

[DanH]

1963 Ranchero V8 / 4 Speed
Granada swap front disc set up. No proportioning valve.
I've converted the master cylinder to a dual resevoir style unit with no isuue until recently. I'm not getting a good return on the master and it's keeping the front calipers "engaged". Is it just the master cylinder going bad? Could bleeding the system help maybe? If I need to throw another unit on it, what would you suggest as far as bore size?
Thanx in advance!
Mike

got your foot on the stop pedal going up a grade ?

try flex hose or caliper piston stuck or sliders frozen . just open the line or bleeder and see if brakes release

 

[65FalconLover]

I'm not sure about your problem but I do think you need a proportioning valve if you're running a disc/drum combo. I had one on my car and left it on when I added the rear disc kit so it's still adjustable. Might be your problem but I'm just not sure.

John

 

[iwantmore]

As Dan said if you crack a bleed you will know if it is stuck or holding pressure. With a similar set up I used a non power Granada disc master and it bolted in and worked great. I also added a prop valve which can help with bias if needed.

 

[finkster]

Thanx for all the reply's!
The brakes aren't "frozen". When I take my foot off of the pedal the brakes are still slightly "applied". If I reach down an pull the brake pedal up, they fully release. I've never had an issue with brake bias but I'll definetly look into installing a valve. It can't hurt right?
Mike

 

[PSIG]

Disconnect the pushrod from the brake pedal to see if it's pedal shaft/bushing binding or MC return that is the issue. Work that direction.

A proportioning valve may or may not be needed. Only testing can tell you that. As you'll have to test after installing one anyway, you might as well test first to see if you even need it. Every setup is considered unique and must be tested.

What MC do you have on there now?

David

 

[thekingofazle]

When I switched MC's I had to shorten my pushrod for it to work. I just removed the brake pedal assembly from the car and put the MC on it on the bench and got the geometry the way I wanted it to figure out how long it needed to be (I ended up threading it and making it adjustable)

If it's slightly too long it may be hanging up/at an odd angle that just can't push back that little bit.

 

[DanH]

Disconnect the pushrod from the brake pedal to see if it's pedal shaft/bushing binding or MC return that is the issue. Work that direction.

A proportioning valve may or may not be needed. Only testing can tell you that. As you'll have to test after installing one anyway, you might as well test first to see if you even need it. Every setup is considered unique and must be tested.

What MC do you have on there now?

David

yes on the bushing or worn shaft.
op didn't say picking up the pedal releaces the brakes

 

[finkster]

Upon further review.....
I believe it's the pedal hanging up. If I pull the pedal up it stays in wherever position I leave it in. I'll get under there tomorrow to clean and lube it all up to meke that pedal swings free. It's deinitely not a push rod issue. When I pull that pedal up, I can see space between the push rod and the recess in the back of the master cylinder. Yes, the boot is torn.
Gotta get this handled before I split to Bonneville.
Thanx for all the direction. I'll update next week!!
Later, Mike

 

[finkster]

1963 Ranchero V8 / 4 Speed
Granada swap front disc set up. No proportioning valve.
I've converted the master cylinder to a dual resevoir style unit with no isuue until recently. I'm not getting a good return on the master and it's keeping the front calipers "engaged". Is it just the master cylinder going bad? Could bleeding the system help maybe? If I need to throw another unit on it, what would you suggest as far as bore size?
Thanx in advance!
Mike

Okay, we are good to go. Not a bad master cylinder and the brakes no longer stay "engaged" with my foot off of the pedal. What was it you ask? A binding pushrod at the pedal. The lock nut was overtightened and the pushrod wasn't able to pivot. It was stiff and inflexible. I removed the nut and put a flat washer between the nut and the brake pedal and tightened the nut until it was tight but still allowed the push rod to pivot. I'm trying to source some thin flat washers made out of brass or bronze that will self lubriacte and make it even smoother. Thanx to everyone that made the gears in my head start turning! Off to Bonneville!!

 

[puttster]

Well done, fink.

 

[finkster]

Well done, fink.

Thanx!! It's such a good feeling to fix stuff like that. I don't know why but it gives a man confidence!!

 

[DanH]

Okay, we are good to go. Not a bad master cylinder and the brakes no longer stay "engaged" with my foot off of the pedal. What was it you ask? A binding pushrod at the pedal. The lock nut was overtightened and the pushrod wasn't able to pivot. It was stiff and inflexible. I removed the nut and put a flat washer between the nut and the brake pedal and tightened the nut until it was tight but still allowed the push rod to pivot. I'm trying to source some thin flat washers made out of brass or bronze that will self lubriacte and make it even smoother. Thanx to everyone that made the gears in my head start turning! Off to Bonneville!!

overtighten nut ??? that was ok on day one

 

[finkster]

overtighten nut ??? that was ok on day one

Wadda you mean, "that was ok on day one"? Day one of what?
I didn't overtighten it. I found it that way and solved the problem it was causing. What's the big deal?

 

[PSIG]

According to my DanH-to-English translator, I think he means it was not over-tightened the day you (or someone) put it on. So, it tightened itself over time, and may happen again if you don't take positive steps to prevent it. This is actually quite common with pivot points using threaded retainers, and is most easily solved by using a locking nut, adding a jam nut, using thread locker, or pinning it with safety wire or cotter pin to hold the retaining nut at a good clearance while preventing the assembly from self-tightening. You need to be positive it cannot self-tighten. Next time it may stick hard with the pedal up instead of down.

I've had the same issue on the dual-quad throttle linkage on my first serious performance car - one of the nuts on the rod joining the two throttle arms self-tightened. The throttle felt a bit odd one day, and then stuck when I hit WOT and just stayed there. After briefly screaming, a quick flick of the ignition switch saved the day. It was a close call and I used-up one of my 9 lives. Lesson learned. There is no ON/OFF switch for your brakes.

David

 

[finkster]

According to my DanH-to-English translator, I think he means it was not over-tightened the day you (or someone) put it on. So, it tightened itself over time, and may happen again if you don't take positive steps to prevent it. This is actually quite common with pivot points using threaded retainers, and is most easily solved by using a locking nut, adding a jam nut, using thread locker, or pinning it with safety wire or cotter pin to hold the retaining nut at a good clearance while preventing the assembly from self-tightening. You need to be positive it cannot self-tighten. Next time it may stick hard with the pedal up instead of down.

I've had the same issue on the dual-quad throttle linkage on my first serious performance car - one of the nuts on the rod joining the two throttle arms self-tightened. The throttle felt a bit odd one day, and then stuck when I hit WOT and just stayed there. After briefly screaming, a quick flick of the ignition switch saved the day. It was a close call and I used-up one of my 9 lives. Lesson learned. There is no ON/OFF switch for your brakes.

David

Understood. Thanx for the translation. I'll change out the lock nut that's on there. It's the type that has the center squished. I like the nylocks style better. Thanx for hammering home the importance of making it right.