68 Mustang brake problems. HELP!

windsor · 06-16-2006, 09:00 AM

I have a 68 with power front disc rear drum. It was originally a 4wheel manual drum car. I have done everything to the car, all ford stuff, just like in 68. My problem is that when I step on the brakes, they are sooo sensitive. If I were to step on them normal, to moderate, I would go through the windshield. SO I have to barely press the brake pedal to slow normally. Then my second problem is by doing this, my brake lights do not go on. I have such light pressure on the pedal that they dont even trigger. I have the correct pedal and support, master and booster, and dist block and proportioning valve. So what gives. I feel that if I had to press on the pedal with more effort to stop, my lights would go on. Any help is appreciated, and thanks in advance for all your help.

Brad

Dark Knight · 06-16-2006, 09:15 AM

Did you change the actuating rod out too? And do the back brakes work? Proportioning valve may be stuck.

Dark Knight · 06-16-2006, 09:21 AM

And try the brakes when the car isnt running... brake lights should work.. or use something to push on the switch with...

Oh yeah, the pedals are different for maual and power brakes.. did you swithc that too? Need more leverage for the manual brakes.

windsor · 06-16-2006, 09:22 AM

The booster/master came as one assembly. I do have a ford service part proportioning valve on the shelf. What would a bad proportioning valve do or not do? What would a bad brake booster do/ not do? I have had people tell me it is one of these two. just dont wanna run out and blow 300+ for a new brake booster

Dark Knight · 06-16-2006, 09:27 AM

If the booster is bad, it will be like manual brakes..only harder to stop..
The reason I asked about the valve was maybe all the pressure was going to the front brakes..

I bet you need to change the pedal though
http://mustangsunlimited.com/itemdy0...atkey=EMUSTANG

windsor · 06-16-2006, 12:56 PM

The pedal is from and for a 68 with power disc.

Dark Knight · 06-16-2006, 01:23 PM

well, I'd make sure the back brakes are working... does it nose dive or the rear come up? Mine wasnt that sensitive...

bears4ever · 06-16-2006, 04:44 PM

Hey Brad
I converted mine over to power front disk and rear drum. You will have to change the brake switch for the rear lights to work. There are 3 kinds out there. Manual/power drum/power front disk. Looks as if you will need the power front disk. As for the stoping problem ? It does sound as if you are not getting any back braking. Try disconecting the power poster from the intake and see what the difference is. How were the brakes bled? You should use a pump style and do it about 3-4 times to get all the air out of the lines. This could also be the problem. What about re-bleeding the master?Just a suggestion. Good luck

Gearhead999 · 06-16-2006, 05:31 PM

You do need to change the pedal/linkage assy. I'd also check the push rod after I got the correct pedal assy installed.

You have to see also which brakes are working and which aren't. Do the rears lock up?? Do the front lock up?? Do you have the proportioning valve plumbed correctly??

windsor · 06-16-2006, 10:32 PM

All the stuff is for a 68 with power disc fronts. Pedal, sepport, master, booster, switch etc. Everything. It has the original proportioning inline off of the distribution block. I am thinking that this may be bad. It is the original ford one ( longer slim cylinder) Which way should it be mounted? Maybe I have it Backwards? I do not believe there is any arrows on it to signify the correct way. What markings can tell me which way is up?

windsor · 06-20-2006, 02:47 PM

I tried the gravel trick. The fronts lock up befor the rears do. So that eliminates the proportioning valve. So I have a very hard pedal with the assist on, and also avery stiff pedal without the assist. It may drop 1/2 inch, then be like you had something stopping it behind it. The more you press, it still does not move. Bad booster? Or something else.

stanger66 · 06-21-2006, 09:18 PM

Usually the rear will lock up before the front because you have no weight in the rear all the weight is in the front holding the front wheels to the ground. It sounds like your
proportioning valve or brake lines arent flowing properly to the rear.Try bleeding first and replace proportioning valve go from there.

06-16-2006, 09:00 AM	#1
windsor Registered Member Join Date: Jun 2006 Posts: 6	68 Mustang brake problems. HELP! I have a 68 with power front disc rear drum. It was originally a 4wheel manual drum car. I have done everything to the car, all ford stuff, just like in 68. My problem is that when I step on the brakes, they are sooo sensitive. If I were to step on them normal, to moderate, I would go through the windshield. SO I have to barely press the brake pedal to slow normally. Then my second problem is by doing this, my brake lights do not go on. I have such light pressure on the pedal that they dont even trigger. I have the correct pedal and support, master and booster, and dist block and proportioning valve. So what gives. I feel that if I had to press on the pedal with more effort to stop, my lights would go on. Any help is appreciated, and thanks in advance for all your help. Brad

06-16-2006, 09:15 AM	#2
Dark Knight Registered Member Join Date: Oct 1998 Location: Az Posts: 854	Re: 68 Mustang brake problems. HELP! Did you change the actuating rod out too? And do the back brakes work? Proportioning valve may be stuck. __________________ 84 convt,roller 302,AFR's, performer 3.55's, underdrives BBK shorties stock cam, 1.7's 13.58@102.84 and a '68 stang .. project 8 sec street car... 557 big block + N20 :-) http://members.cox.net/darkknight302/68nwrear.jpg

06-16-2006, 09:21 AM	#3
Dark Knight Registered Member Join Date: Oct 1998 Location: Az Posts: 854	Re: 68 Mustang brake problems. HELP! And try the brakes when the car isnt running... brake lights should work.. or use something to push on the switch with... Oh yeah, the pedals are different for maual and power brakes.. did you swithc that too? Need more leverage for the manual brakes. __________________ 84 convt,roller 302,AFR's, performer 3.55's, underdrives BBK shorties stock cam, 1.7's 13.58@102.84 and a '68 stang .. project 8 sec street car... 557 big block + N20 :-) http://members.cox.net/darkknight302/68nwrear.jpg

06-16-2006, 09:22 AM	#4
windsor Registered Member Join Date: Jun 2006 Posts: 6	Re: 68 Mustang brake problems. HELP! The booster/master came as one assembly. I do have a ford service part proportioning valve on the shelf. What would a bad proportioning valve do or not do? What would a bad brake booster do/ not do? I have had people tell me it is one of these two. just dont wanna run out and blow 300+ for a new brake booster

06-16-2006, 09:27 AM	#5
Dark Knight Registered Member Join Date: Oct 1998 Location: Az Posts: 854	Re: 68 Mustang brake problems. HELP! If the booster is bad, it will be like manual brakes..only harder to stop.. The reason I asked about the valve was maybe all the pressure was going to the front brakes.. I bet you need to change the pedal though http://mustangsunlimited.com/itemdy0...atkey=EMUSTANG __________________ 84 convt,roller 302,AFR's, performer 3.55's, underdrives BBK shorties stock cam, 1.7's 13.58@102.84 and a '68 stang .. project 8 sec street car... 557 big block + N20 :-) http://members.cox.net/darkknight302/68nwrear.jpg

06-16-2006, 12:56 PM	#6
windsor Registered Member Join Date: Jun 2006 Posts: 6	Re: 68 Mustang brake problems. HELP! The pedal is from and for a 68 with power disc.

06-16-2006, 01:23 PM	#7
Dark Knight Registered Member Join Date: Oct 1998 Location: Az Posts: 854	Re: 68 Mustang brake problems. HELP! well, I'd make sure the back brakes are working... does it nose dive or the rear come up? Mine wasnt that sensitive... __________________ 84 convt,roller 302,AFR's, performer 3.55's, underdrives BBK shorties stock cam, 1.7's 13.58@102.84 and a '68 stang .. project 8 sec street car... 557 big block + N20 :-) http://members.cox.net/darkknight302/68nwrear.jpg

06-16-2006, 04:44 PM	#8
bears4ever Registered Member Join Date: Apr 2004 Location: Canada Posts: 36	Re: 68 Mustang brake problems. HELP! Hey Brad I converted mine over to power front disk and rear drum. You will have to change the brake switch for the rear lights to work. There are 3 kinds out there. Manual/power drum/power front disk. Looks as if you will need the power front disk. As for the stoping problem ? It does sound as if you are not getting any back braking. Try disconecting the power poster from the intake and see what the difference is. How were the brakes bled? You should use a pump style and do it about 3-4 times to get all the air out of the lines. This could also be the problem. What about re-bleeding the master?Just a suggestion. Good luck

06-16-2006, 05:31 PM	#9
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	Re: 68 Mustang brake problems. HELP! You do need to change the pedal/linkage assy. I'd also check the push rod after I got the correct pedal assy installed. You have to see also which brakes are working and which aren't. Do the rears lock up?? Do the front lock up?? Do you have the proportioning valve plumbed correctly?? __________________ "Support our Troops" Dave 1968 Cougar 2004 Thunderbird 2007 F150 Harley-Davidson, SuperCrew 1986 LTD 1997 Ranger 1992 Honda Civic

06-16-2006, 10:32 PM	#10
windsor Registered Member Join Date: Jun 2006 Posts: 6	Re: 68 Mustang brake problems. HELP! All the stuff is for a 68 with power disc fronts. Pedal, sepport, master, booster, switch etc. Everything. It has the original proportioning inline off of the distribution block. I am thinking that this may be bad. It is the original ford one ( longer slim cylinder) Which way should it be mounted? Maybe I have it Backwards? I do not believe there is any arrows on it to signify the correct way. What markings can tell me which way is up?

06-20-2006, 02:47 PM	#11
windsor Registered Member Join Date: Jun 2006 Posts: 6	Re: 68 Mustang brake problems. HELP! I tried the gravel trick. The fronts lock up befor the rears do. So that eliminates the proportioning valve. So I have a very hard pedal with the assist on, and also avery stiff pedal without the assist. It may drop 1/2 inch, then be like you had something stopping it behind it. The more you press, it still does not move. Bad booster? Or something else.

06-21-2006, 09:18 PM	#12
stanger66 dreaming about mustangs Join Date: Mar 2006 Location: laurel, md Posts: 178	Re: 68 Mustang brake problems. HELP! Usually the rear will lock up before the front because you have no weight in the rear all the weight is in the front holding the front wheels to the ground. It sounds like your proportioning valve or brake lines arent flowing properly to the rear.Try bleeding first and replace proportioning valve go from there. __________________ Ross 06 Saleen S281SC Convertible 6spd 04 Freestar(wife) 66 mustang w/orig. Carroll Shelby racing 7 spoke 14X7's aluminum 02 pontiac sunfire 2.2 ecotec(great gas mileage) still GM junk

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