Omg....need Help.

1969 Stang · 03-27-2002, 10:53 PM

First my brakes a sort of new...front disc rear drum...now the brake pedal has to be almost all the way down for me to stop at a stop sign or stop light...and so on...now when I push the pedal even a little bit I hear a hisss sound...kind of like when you let out the air in a coke bottle slow...what could be the problem...Its scary to drive my car...and now its going to rain...if no one knows just pray...thanks. I also put this into the classic forum..I need all the help I can get.

srv1 · 03-27-2002, 10:55 PM

is it leaking fluid? check that first. if not maybe a bad booster

1969 Stang · 03-27-2002, 11:04 PM

I don't think its leaking fluid...I just put some 1 week ago. And it really doesn't look any differen't. thanks...hope that helps you out some? How much does a booster cost? Im so worried my poor baby.

srv1 · 03-27-2002, 11:37 PM

could also be a bad master cylinder

Mercury · 03-28-2002, 12:04 AM

Brakes are sort of new??? Did you have the rear wheel cylinders replaced, or a brake line?

Might be they just need bled. And usually when a Vacum assist Power brake booster gets a leak or goes bad the pedal does not want to move at all.It makes for a very, very, very stiff pedal. You have to stand (Literally) on the brakes.

joe4speed · 03-28-2002, 02:45 AM

I agree with bleeding them! Give it a shot!

Crazy Horse GT · 03-28-2002, 07:52 AM

also if it's original ck the little round vacum valve on the out side of your booster,i had to buy one before i drove my 69 grande home,the bozo i bought it from-cough-chevy guy-cough had put tape over it

mustangman65_79 · 03-28-2002, 10:39 AM

If u bleed the brakes, and it still does the same, it's the brake master Cyl. Only about $30. I think it will be just that, a new master cyl. My bronco did the same thing when I replaced my brakes. When a master cyl gets worn, along twith the old brakes, it will still work, but when U replace the brakes, the master cyl is now having pressure build up when is wasen't used to having it. What is happening is the pressure of the fluid is bypassing through the seals, back into your Resivor. Also, you'll notice that your new brakes will wear faster then before. This is because the fluid that is bypassing the seals, is making backpressure, so when U let off the brakes, the back pressure will make the brakes rub harder then normal. Making abnormal wear. Hope this helps.

1969 Stang · 03-31-2002, 10:05 PM

update:
went to my uncles friends place...He said I may need a electric vacuum pump or something like that...I have a very mild cam in the beast. Now the master cly. has recently been replaced. I haven't tried bleeding the brakes YET. Now the pedal has changed some I push it in about 1-3 inchs. and it hisses. and from there on get ready to stand on the brakes to stop that thing. It is very hard...The did a test on the vacuum at the brake booster took off a hose. The test is as followed.
at idle 500-600RPM. 10 psi of vacuum. at about 3kRPM it was at 40psi. So does that help anyone...I don't know anymore...
p.s. thanks for all the help

Old Guy with 87 GT · 03-31-2002, 11:33 PM

sounds like the brake booster is bad .....my 78 did the same thing when the booster was going out.........

sounds like you got plenty of vacuum

03-27-2002, 10:53 PM	#1
1969 Stang Registered Member Join Date: Dec 2001 Location: Pomona, CA Posts: 93	Omg....need Help. First my brakes a sort of new...front disc rear drum...now the brake pedal has to be almost all the way down for me to stop at a stop sign or stop light...and so on...now when I push the pedal even a little bit I hear a hisss sound...kind of like when you let out the air in a coke bottle slow...what could be the problem...Its scary to drive my car...and now its going to rain...if no one knows just pray...thanks. I also put this into the classic forum..I need all the help I can get. __________________ Go Ahead.... Unleash your beast.... Mine will be waiting.... Ricer Hater's Club - Member #37

03-27-2002, 10:55 PM	#2
srv1 Get down..... Join Date: Apr 2001 Location: Room 103 Posts: 2,095	is it leaking fluid? check that first. if not maybe a bad booster __________________ Cobra brakes are on! Finally..... ------------------------------------------------

03-27-2002, 11:04 PM	#3
1969 Stang Registered Member Join Date: Dec 2001 Location: Pomona, CA Posts: 93	I don't think its leaking fluid...I just put some 1 week ago. And it really doesn't look any differen't. thanks...hope that helps you out some? How much does a booster cost? Im so worried my poor baby. __________________ Go Ahead.... Unleash your beast.... Mine will be waiting.... Ricer Hater's Club - Member #37

03-27-2002, 11:37 PM	#4
srv1 Get down..... Join Date: Apr 2001 Location: Room 103 Posts: 2,095	could also be a bad master cylinder __________________ Cobra brakes are on! Finally..... ------------------------------------------------

03-28-2002, 12:04 AM	#5
Mercury The Redneck James Bond Join Date: Sep 2000 Location: Fayetteville NC Posts: 1,707	Brakes are sort of new??? Did you have the rear wheel cylinders replaced, or a brake line? Might be they just need bled. And usually when a Vacum assist Power brake booster gets a leak or goes bad the pedal does not want to move at all.It makes for a very, very, very stiff pedal. You have to stand (Literally) on the brakes. __________________ 64 1/2 "D" code Red Mustang Coupe. Red Baron, 2000 Perf Red Mustang GT. 5spd. Stage 2 CNC heads with Large Valves, Comp Cams (270-274 dur .550 lift), Forged Crank, DRP pistons, Manly H-beams, Pro M 87 mm Mass Air, 24lb Inj, 75mm TB, Plenum Spacer ,Long Tube Headers, Homemade H-pipe, 2 chamber Flows, 4:10's, Steeda Tri-Ax, LKW 70/30's, Eibach Drag Springs, Steeda SubFrames, Battle Boxes, Rear Girdle, Adj uppers, Alunimum Drshft, Southside Lift Bars. Project Cars, 64 1/2 6cyl coupe, 1930 Model A Nostalgia Rod.

03-28-2002, 02:45 AM	#6
joe4speed He said Member...heh, heh Join Date: Sep 1999 Location: Jupiter, Florida U.S.A. Posts: 3,718	I agree with bleeding them! Give it a shot! __________________ *Joe!* 1988 GT, 13.58@101mph Check out my listing! Click here! Or my website:www.joe4speed.com

03-28-2002, 07:52 AM	#7
Crazy Horse GT Registered Member Join Date: Aug 2001 Location: Sale Creek, TN. C. S. A. Posts: 4,652	also if it's original ck the little round vacum valve on the out side of your booster,i had to buy one before i drove my 69 grande home,the bozo i bought it from-cough-chevy guy-cough had put tape over it __________________ 95 gt vert, lot's of stuff, it aint slow. 04 sonic blue v - six my beater 89 rs camaro iroc turbo hood, other stuff, my wifes ride 84 lx stang cammed up 289 hi po, etc 65 falcon, maybe by the year 2020. black 00gt, gone but never forgotten. R H C- member # 1 o.b.c. da prez- member # 1 if your under 40 dont ask. goodbye for now odie,r.i.p. 11-27-03

03-28-2002, 10:39 AM	#8
mustangman65_79 My poor 79 RIP Join Date: Oct 2001 Location: Suisun City, Posts: 2,320	If u bleed the brakes, and it still does the same, it's the brake master Cyl. Only about $30. I think it will be just that, a new master cyl. My bronco did the same thing when I replaced my brakes. When a master cyl gets worn, along twith the old brakes, it will still work, but when U replace the brakes, the master cyl is now having pressure build up when is wasen't used to having it. What is happening is the pressure of the fluid is bypassing through the seals, back into your Resivor. Also, you'll notice that your new brakes will wear faster then before. This is because the fluid that is bypassing the seals, is making backpressure, so when U let off the brakes, the back pressure will make the brakes rub harder then normal. Making abnormal wear. Hope this helps. __________________ '84 mustang GT turbo '85 LTD '89 Camaro Irocz z28 '94 Lightning '96 Trans am

03-31-2002, 10:05 PM	#9
1969 Stang Registered Member Join Date: Dec 2001 Location: Pomona, CA Posts: 93	update: went to my uncles friends place...He said I may need a electric vacuum pump or something like that...I have a very mild cam in the beast. Now the master cly. has recently been replaced. I haven't tried bleeding the brakes YET. Now the pedal has changed some I push it in about 1-3 inchs. and it hisses. and from there on get ready to stand on the brakes to stop that thing. It is very hard...The did a test on the vacuum at the brake booster took off a hose. The test is as followed. at idle 500-600RPM. 10 psi of vacuum. at about 3kRPM it was at 40psi. So does that help anyone...I don't know anymore... p.s. thanks for all the help __________________ Go Ahead.... Unleash your beast.... Mine will be waiting.... Ricer Hater's Club - Member #37

03-31-2002, 11:33 PM	#10
Old Guy with 87 GT Registered Member Join Date: May 2001 Location: Harrisburg, Pennsylvania Posts: 379	sounds like the brake booster is bad .....my 78 did the same thing when the booster was going out......... sounds like you got plenty of vacuum __________________ the "not so old",old guy 87 Mustang GT T-top >hanlon t-5, pro 5.0, centerforce clutch ,adj. cable/quatrant ,3.27s ,full 2 1/2 ex(off road H) adj. reg. ,e-cam ,70mm TB, cobra intake ,1.7rr ,ported/milled e7ets w/crane springs ,306 balaced/decked short block w/speed pro forged flat top pistons ...257rwhp/302rwt best et 13.7@102 (4/11 ) '80 Capri (future project,currently collecting parts for 351 moter)