brakes

Reply Subscribe

Thread Tools

Search this Thread

Oct 16, 2002 | 08:29 PM

fordmaniac21

Thread Starter

Elder User

Joined: Sep 2000

Posts: 718

Likes: 0

From: Golden ,CO USA

brakes

my power brake booster went out on my truck a few weeks back. i ordered a new one from napa on monday and it got here today. it is exactly identical to my old one. my problem is, after i put it in this evening, when it was all hooked up. the brake pedal didnt return to the full up position like it did befor i replaced the booster. the pedal has a much firmer feel to it now like it should. i know all the pads are new because i replaced them about 2 months ago and they r hardly warn. and i replaced the master cylender about 3 months ago when it went out on me so i know it isnt that. is there an adjustment that i missed in the install of the new booster??? my manual doesnt say anything about any. has anyone had this problem befor and what did u do to correct it???????
'75 F-100 4x4, 4" lift
35x15.5x15 super swamper TSL/SX
mini-spooled 9" rear end
390 w/ cam,headers,
and 4 barrell edelbrock

TRIED TRUE and FORD BLUE

Oct 16, 2002 | 09:01 PM

Torque1st

Posting Legend

Joined: Sep 2001

Posts: 30,255

Likes: 37

brakes

If you made the proper adjustment on the master cylinder push rod, there may be another problem. If you grabbed the booster by the brake input rod you may have dislodged the rubber reaction disk inside the booster control valve. There are some good pictures in the OEM manuals of this disk. If you can't get it back in place the new booster is shot. There is a nice warning sticker somewhere on the box or in it about grabbing the booster by the input rod or nose. Unfortunately it is a natural place to grab and you never see the warning until it is too late.

Oct 16, 2002 | 09:06 PM

fordmaniac21

Thread Starter

Elder User

Joined: Sep 2000

Posts: 718

Likes: 0

From: Golden ,CO USA

brakes

the new booster came with a new rod for the master cylender. do i need to adjust it??? i just out it in the way it came out of the box. there was also a spacer on the new booster that i didnt have on my old unit. it is on there now but i had taken it off to see if that was the problem but still the same thing, the pedal didnt go the hole way up. i put it back on just befor i got hungry and came in for the night.
'75 F-100 4x4, 4" lift
35x15.5x15 super swamper TSL/SX
mini-spooled 9" rear end
390 w/ cam,headers,
and 4 barrell edelbrock

TRIED TRUE and FORD BLUE

Oct 16, 2002 | 09:53 PM

Torque1st

Posting Legend

Joined: Sep 2001

Posts: 30,255

Likes: 37

brakes

Yep! You have to make the adjustments for your master cylinder. The dimension you need will depend on the master cylinder you have. After a cylinder has been replaced you never know where you are at. I always buy a master cylinder booster combo from the remanufacturer to make sure everything is adjusted OK.

The spacer is for gross adjustments for different master cylinder/booster combos.

Oct 17, 2002 | 12:58 PM

Thudpucker

Posting Guru

Joined: Jan 2000

Posts: 1,899

Likes: 1

From: Cullman Alabama

brakes

You say the "Brake pedal wont return to the Full up position?"
That's more likely up above the brake pedal arm. At the Rubber stop.
If you can pull the pedal up to full hight, that means something inside the Vacuam cylinder.

Oct 17, 2002 | 08:01 PM

fordmaniac21

Thread Starter

Elder User

Joined: Sep 2000

Posts: 718

Likes: 0

From: Golden ,CO USA

brakes

[updated:LAST EDITED ON 17-Oct-02 AT 09:06 PM (EST)]well i messes with it today and got the pedal to go further up. it still isnt the way it was. i dunno what it is. i dont see a rubber pedal stop near the brake pedal. the pedal stops when the brake light swith is pressed. i am thinking that i have to adjust the rod between the master and the booster. the directions that came with it r pretty vague and say to have someone press the pedal and watch in the master cylinder for a decrease in fluid and tells you to adjust accordingly. i only had a little bit of time to adjust it at lucnh and when i got home from work it was raining. so hopefully i can get time tommorow after work or this weekend. i just put my new tires on and want to go try them out pssibly this weekend. the mud is going to be great to try out the swamoers in after all this rain. any other suggestions??? when i was bleeding my brakes today, i did this thinking it might be the problem, i noticed that the front rubber brake lines were flexxing a little bit when preasure was on the pedal.. could this be part of my problem????
'75 F-100 4x4, 4" lift
35x15.5x15 super swamper TSL/SX
mini-spooled 9" rear end
390 w/ cam,headers,
and 4 barrell edelbrock

TRIED TRUE and FORD BLUE