*sigh*...when will it end. "Brake question and troubles

[MYRIDE]

[/quote][/quote]"If you have one of the combination valves installed. both lines from the master cylinder go to it and then 2 come out for the front brakes and one for the rear. There is a shuttle valve inside. It is to shut off the fluid supply should a line brake . On the top of this valve is a little plug for a wire. I use to think it was to let you know when the fluid was low. Not the case it is to light up a light to show part of the system has a problem.  When ever you bleed your brakes put a test light or meter on the center stud on the switch. This switch will groud if a problem is there. The light or meter will show this. Master Power Brake web site shows how to correct this problem. It is possible not to have brakes on the front or the rear and never know it. Always check this after you  bleed the brakes. Don't need to hold the pedal down just use you test light or meter. I learned the hard way
HELP!!![/quote][/quote]

Kctom, can't seem to locate that info on MP Brakes, can you remember where you spotted it?
Thanks, K

[Ed ke6bnl]

I hope I am not really changing the topic but I have been bothered by a brake problem since I got my 50 F1 on the road, mustang II, 9" rear with drum brakes, proportional valve, 2 and 10 psi residuals, an a power brake under the floor,  The brakes work and are solid, even broke a rear brake line and the fronts worked till I repaired it.  The problem is it does not feel like I have power brakes, I have vacuum from the rear of the intake manifold. What test or advice do you recommend for me to test and resolve this on going problem Ed ke6bnl

Any chance you have the vacuum sourced to a thermal vacuum switch?
Thermal vacuum switches look very much like a vertical vacuum block (like in fuel block) but some of the bibs don't get vacuum until the engine is way hot.

I used a threaded I believe 3/8 hole behind the carb. on this offenhouser intake on a 327 motor. I just screwed in a 3/8 barbed fitting. Never did I think that the one big problem I would have would be from the M/C being this is the first time I have ever done any project of this kind.  I thought the bigger issue would be the engine trans or rear end which all went together smoothly and seems to perform very well, even the mustang II install was smooth.  Thanks Ed

[Dave]

Ok rodders....
New MP Brake system (under floor)
New 11" Disc/rotor system up front
Rebuilt (completely) 10x2.5" drums in rear
New lines, proportioning (combination)valve, 2 & 10 lbs residual valves.

LOTS of front end pressure, NO preassure for the rear. Pedal is firm and then gets spongier the more I use it. Have bled and bled and bled the system. Checked M/C, proportioning valve and seem to have lots of flow on the other side of my residual (10 lb.

My question (finally)"could" my residual NOT be holding 10 lbs pressure inline and alowing the system to "bleed back"?
This has me so pi**ed I threw the tires back on and took her for a midnight ride around the neihborhood last night (much to my neighbors chagrin!)

HELP!!!

Interesting. My system is disk front drum rear manual set up and it acts kind of like yours. I do believe ive got enuff pressure to the rears and the pedal isnt spongy the fronts just grab a lot better than the rears. The one thing I havent done yet is to pull the wheels and drums and check if the shoes are on the right way. So where does the shorter shoe go ? front or rear..
Dave

[MYRIDE]

Ok rodders....
New MP Brake system (under floor)
New 11" Disc/rotor system up front
Rebuilt (completely) 10x2.5" drums in rear
New lines, proportioning (combination)valve, 2 & 10 lbs residual valves.

LOTS of front end pressure, NO preassure for the rear. Pedal is firm and then gets spongier the more I use it. Have bled and bled and bled the system. Checked M/C, proportioning valve and seem to have lots of flow on the other side of my residual (10 lb.

My question (finally)"could" my residual NOT be holding 10 lbs pressure inline and alowing the system to "bleed back"?
This has me so pi**ed I threw the tires back on and took her for a midnight ride around the neihborhood last night (much to my neighbors chagrin!)

HELP!!!

Interesting. My system is disk front drum rear manual set up and it acts kind of like yours. I do believe ive got enuff pressure to the rears and the pedal isnt spongy the fronts just grab a lot better than the rears. The one thing I havent done yet is to pull the wheels and drums and check if the shoes are on the right way. So where does the shorter shoe go ? front or rear..
Dave

Dave, the "lead shoe" is the longer of the two, usually the front one.

[58 Yeoman]

The lead shoe is the shorter of the two. When going forward, and you hit the brakes, the rear shoe catches all the weight. We used to bleed the rear or the front to get that switch to center itself. Took a couple tries to get it, depending on which way it went.

[phat rat]

I hope I am not really changing the topic but I have been bothered by a brake problem since I got my 50 F1 on the road, mustang II, 9" rear with drum brakes, proportional valve, 2 and 10 psi residuals, an a power brake under the floor,  The brakes work and are solid, even broke a rear brake line and the fronts worked till I repaired it.  The problem is it does not feel like I have power brakes, I have vacuum from the rear of the intake manifold. What test or advice do you recommend for me to test and resolve this on going problem Ed ke6bnl

Rule of thumb is 18 inches of vacuum at an engine idle at the booster.

Yea that's the same song and dance MPB gave me, but the stock parts will work great at less vacumn

[enjenjo]

I hope I am not really changing the topic but I have been bothered by a brake problem since I got my 50 F1 on the road, mustang II, 9" rear with drum brakes, proportional valve, 2 and 10 psi residuals, an a power brake under the floor,  The brakes work and are solid, even broke a rear brake line and the fronts worked till I repaired it.  The problem is it does not feel like I have power brakes, I have vacuum from the rear of the intake manifold. What test or advice do you recommend for me to test and resolve this on going problem Ed ke6bnl

Any chance you have the vacuum sourced to a thermal vacuum switch?
Thermal vacuum switches look very much like a vertical vacuum block (like in fuel block) but some of the bibs don't get vacuum until the engine is way hot.

I used a threaded I believe 3/8 hole behind the carb. on this offenhouser intake on a 327 motor. I just screwed in a 3/8 barbed fitting. Never did I think that the one big problem I would have would be from the M/C being this is the first time I have ever done any project of this kind.  I thought the bigger issue would be the engine trans or rear end which all went together smoothly and seems to perform very well, even the mustang II install was smooth.  Thanks Ed

If the pushrod from the pedal to the booster does not have enough free play, It will hold the booster "on" just enough to bleed off the vacuum. Then when you hit the brakes, no boost.

If the engine stumbles when you hit the brakes at slow speeds, or idle speed increases with brake application when setting, this may be the problem

[32 Chevy]

I hope I am not really changing the topic but I have been bothered by a brake problem since I got my 50 F1 on the road, mustang II, 9" rear with drum brakes, proportional valve, 2 and 10 psi residuals, an a power brake under the floor,  The brakes work and are solid, even broke a rear brake line and the fronts worked till I repaired it.  The problem is it does not feel like I have power brakes, I have vacuum from the rear of the intake manifold. What test or advice do you recommend for me to test and resolve this on going problem Ed ke6bnl

Any chance you have the vacuum sourced to a thermal vacuum switch?
Thermal vacuum switches look very much like a vertical vacuum block (like in fuel block) but some of the bibs don't get vacuum until the engine is way hot.

I used a threaded I believe 3/8 hole behind the carb. on this offenhouser intake on a 327 motor. I just screwed in a 3/8 barbed fitting. Never did I think that the one big problem I would have would be from the M/C being this is the first time I have ever done any project of this kind.  I thought the bigger issue would be the engine trans or rear end which all went together smoothly and seems to perform very well, even the mustang II install was smooth.  Thanks Ed

If the pushrod from the pedal to the booster does not have enough free play, It will hold the booster "on" just enough to bleed off the vacuum. Then when you hit the brakes, no boost.

If the engine stumbles when you hit the brakes at slow speeds, or idle speed increases with brake application when setting, this may be the problem

Hmmm, it sure seems like a lot of us have similar problems. The brakes in my car work O.K., but just dont feel as positive as my other cars. the brake system came entirely out of a donor car (Granada) . Front discs, booster, proportioning valve, pedal, differential, etc. all came from the same car and worked well before I yanked the parts and stuck them in the 56 ranchwagon. The only change I made was the pushrod because the firewalls were different thickness. So how can you test for the correct length of pushrod?

[enjenjo]

There should be at least 1/8"of free play measured at the pin in the pushrod attachement to the pedal. In other words, if you remove the pin, you should be able to raise the pedal enough to miss align the hole by 1/8". On Fords, for many years they used an eccentric pin to adjust the free play.

For the adjustment of the pushrod from the booster to the master cylinder, I will post pictures and directions for a tool I made that works very well for getting the right adjustment.