BOOSTER or MASTER CYLINDER cause the car to miss up ??

HAITHAM · 01-19-2002, 12:32 AM

The brake was too light when pushed, that's means time of MASTER CYLINDER to change. The car ruining perfect in this time.

Now, the brake is too hard when pushed (like rock) & at the same time car start serious bucking problem & idle dropped down to 500-600 rpm, my friend tolled me this is because the BOOSTER damaged.
He pulls the vacuum line that's connected at the top of the BOOSTER & close the line by his finger, the car idle good no miss up.

Did the BOOSTER or the MASTER CYLINDER cause the car to miss up ?

Unit 5302 · 01-19-2002, 12:42 AM

Your master cylinder has nothing to do with vacuum. It's your power brake booster. I've seen the problem before, forget passing emissions if you have them until you replace the booster.

HAITHAM · 01-19-2002, 03:38 AM

does the booster make the car bucks & hesitate & idle to drop to 500-600 rpm ????

why its related to emission !!

exgmguy · 01-19-2002, 11:16 AM

The booster can leak internally. Remember, it operates on engine vacuum.

mustangman65_79 · 01-19-2002, 02:29 PM

I agree, it's the booster.

Unit 5302 · 01-19-2002, 06:37 PM

If the booster is leaking vacuum, your computer will read the low vacuum as open throttle and inject more fuel.

exgmguy · 01-19-2002, 09:13 PM

No, just replaced. Try plugging the vacuum line that goes to the booster, and driving the car. If the driveability problem goes away, you've found the culprit.

HAITHAM · 01-19-2002, 11:21 PM

that's why I smell unburned fuel.

can be the booster repaired ?

PKRWUD · 01-21-2002, 01:19 AM

The booster's diaphram is damaged, and the booster needs to be replaced. The damaged diaphram will result in a vacuum leak, which will cause the engine to idle rough, and will make it very difficult to use your brakes. I suppose someone somewhere rebuilds boosters, but I've never known them. Just replace it.

Take care,
-Chris

mustangman65_79 · 01-21-2002, 07:37 AM

Some places do repair them, but it costs more then buying a new one. Makes no sence to me.

HAITHAM · 01-21-2002, 11:38 PM

Is there any difference in brake booster betwwen COBRA & GT ?

PKRWUD · 01-22-2002, 09:24 AM

Not that I'm aware of.

Take care,
-Chris

jonnyk · 01-22-2002, 12:24 PM

Yes there is a difference in boosters.
Check out this webpage, #5 Brake Booster Upgrades
http://www.geocities.com/mjbobbitt/mustang/brakes.html

HAITHAM · 01-23-2002, 01:15 AM

BENDIX make the Brake Booster for Ford, I checked their site & I found that Cobra & GT have the same part no.

Last update:

BENDIX make the Brake Booster for Ford, I checked their site & I found that Cobra & GT have the same part no

www.bendixbrakes.com

01-19-2002, 12:32 AM	#1
HAITHAM Registered Member Join Date: Jun 2000 Location: Saudi Arabia Posts: 130	BOOSTER or MASTER CYLINDER cause the car to miss up ?? The brake was too light when pushed, that's means time of MASTER CYLINDER to change. The car ruining perfect in this time. Now, the brake is too hard when pushed (like rock) & at the same time car start serious bucking problem & idle dropped down to 500-600 rpm, my friend tolled me this is because the BOOSTER damaged. He pulls the vacuum line that's connected at the top of the BOOSTER & close the line by his finger, the car idle good no miss up. Did the BOOSTER or the MASTER CYLINDER cause the car to miss up ? __________________ 94 COBRA # 926/5009 TFS track heat heads (ported), Cobra intake (ported), 24# Injectors, 3/8" Phenolic spacer, CompCamsXteremeEnerge 224 232 555'' 565 112, CompCams Pro-Magnum 1.6 RR, BBK 1 5/8" headers, BBK 65mm TB, Pro-M 80mm MAS, Next Generation PIH kit w/ A9L computer, 3.55, BBK 190 lph fuel pump, Paxton fpr, MSD'S, March Pulley's, Pro-5 tower power shifter, Intellitronix Air/Fuel gauge, Eibach Sportline Springs, Tokico 5-way adjustable, Granatelli Motorsport Subframes, Edelbrock Mufflers, 2.5" exhaust system, Pfgoodrich comp T/A drag. Previous Mode: E303 Cam, TFS 1.7 rr '92 Integra LS.

01-19-2002, 06:37 PM	#6
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	If the booster is leaking vacuum, your computer will read the low vacuum as open throttle and inject more fuel. Last edited by Unit 5302; 01-19-2002 at 11:26 PM..

01-21-2002, 01:19 AM	#9
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	The booster's diaphram is damaged, and the booster needs to be replaced. The damaged diaphram will result in a vacuum leak, which will cause the engine to idle rough, and will make it very difficult to use your brakes. I suppose someone somewhere rebuilds boosters, but I've never known them. Just replace it. Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

01-21-2002, 07:37 AM	#10
mustangman65_79 My poor 79 RIP Join Date: Oct 2001 Location: Suisun City, Posts: 2,320	Some places do repair them, but it costs more then buying a new one. Makes no sence to me. __________________ '84 mustang GT turbo '85 LTD '89 Camaro Irocz z28 '94 Lightning '96 Trans am

01-22-2002, 09:24 AM	#12
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Not that I'm aware of. Take care, -Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

01-19-2002, 12:42 AM	#2
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Your master cylinder has nothing to do with vacuum. It's your power brake booster. I've seen the problem before, forget passing emissions if you have them until you replace the booster.

01-19-2002, 03:38 AM	#3
HAITHAM Registered Member Join Date: Jun 2000 Location: Saudi Arabia Posts: 130	does the booster make the car bucks & hesitate & idle to drop to 500-600 rpm ???? why its related to emission !!

01-19-2002, 11:16 AM	#4
exgmguy Registered Member Join Date: Feb 1999 Location: Utica, Michigan Posts: 2,631	The booster can leak internally. Remember, it operates on engine vacuum.

01-19-2002, 02:29 PM	#5
mustangman65_79 My poor 79 RIP Join Date: Oct 2001 Location: Suisun City, Posts: 2,320	I agree, it's the booster. __________________ '84 mustang GT turbo '85 LTD '89 Camaro Irocz z28 '94 Lightning '96 Trans am

01-19-2002, 09:13 PM	#7
exgmguy Registered Member Join Date: Feb 1999 Location: Utica, Michigan Posts: 2,631	No, just replaced. Try plugging the vacuum line that goes to the booster, and driving the car. If the driveability problem goes away, you've found the culprit.

01-19-2002, 11:21 PM	#8
HAITHAM Registered Member Join Date: Jun 2000 Location: Saudi Arabia Posts: 130	that's why I smell unburned fuel. can be the booster repaired ?

01-21-2002, 11:38 PM	#11
HAITHAM Registered Member Join Date: Jun 2000 Location: Saudi Arabia Posts: 130	Is there any difference in brake booster betwwen COBRA & GT ?

01-22-2002, 12:24 PM	#13
jonnyk Being stroked is great Join Date: Oct 1998 Location: Alberta, Canada Posts: 772	Yes there is a difference in boosters. Check out this webpage, #5 Brake Booster Upgrades http://www.geocities.com/mjbobbitt/mustang/brakes.html __________________ Novi 2000 now spinning off the snout of the 331... Mods Pics

01-23-2002, 01:15 AM	#14
HAITHAM Registered Member Join Date: Jun 2000 Location: Saudi Arabia Posts: 130	BENDIX make the Brake Booster for Ford, I checked their site & I found that Cobra & GT have the same part no. Last update: BENDIX make the Brake Booster for Ford, I checked their site & I found that Cobra & GT have the same part no www.bendixbrakes.com

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
master cylinder and prop valve question	shelby2	Classic Mustangs	1	07-05-2002 05:32 PM
master cylinder?	Fostang	Classic Mustangs	0	06-10-2002 01:04 AM
Master Cylinder	Sneaky	Windsor Power	3	03-06-2002 12:13 PM
Looking for a master cylinder...?	k. putman	Windsor Power	0	02-03-2002 07:12 PM
Master Cylinder Booster for 65 Coupe	Dopie	Classic Mustangs	7	06-12-2001 08:00 AM