1996 Jeep ChR Lareado

HELPMYJEEP · 08-29-2007, 08:29 PM

I have change my brake booster. Reason being that I was hearing a hissing noise on the drivers side. Change the brake booster and now the Jeep has a problem getting any speed. I get to 30mph and the jeep feels like its wants to go but has a hard time getting up to speed.
Can some one help me. The hissing noise is gone. now the car seems like its idle or something off. I fix computers not cars.LOL

**qldit** · 08-29-2007, 10:47 PM

Good Afternoon HELPMYJEEP, as you would be aware the booster is simply a large surface area diaphram that uses the engine intake manifold vacuum to create a mechanical advantage over the applied pedal pressure.

Your problem description is odd, if we discount the possibility of your having altered the accellerator cabling and possibility of and vacuum leak then it would possibly indicate that the brake master cylinder and diaphram shaft is mis-rigged and you are driving with partial brakes applied. This could be very ungood!

When the master cylinder is fitted the actual insertion depth of that push-rod is critical and should not cause any piston movement in the actual master cylinder.

I suspect this may be actually happening.

You might check the insertion depth that rod actually has, as a rule of thumb when you actually locate the master cylinder on the booster you should feel no active force from that system.

Is that booster you have a proper part for your model machine?

In many cases that pushrod can be adjusted but you may need the manual for proper adjusting information.

Drive the vehicle for some distance without touching the brakes and feel if the disks have any heat. That may give you a clue if the brakes are permanently partially applied.

Others will have different ideas.

Cheers, qldit.

08-29-2007, 08:29 PM	#1 (permalink)
HELPMYJEEP Registered User Join Date: Aug 2007 Posts: 1 OS: xp	1996 Jeep ChR Lareado I have change my brake booster. Reason being that I was hearing a hissing noise on the drivers side. Change the brake booster and now the Jeep has a problem getting any speed. I get to 30mph and the jeep feels like its wants to go but has a hard time getting up to speed. Can some one help me. The hissing noise is gone. now the car seems like its idle or something off. I fix computers not cars.LOL

08-29-2007, 10:47 PM	#2 (permalink)
qldit TSF Gearhead Join Date: Mar 2007 Location: Brisbane Australia. Posts: 592 OS: All Systems, mainly Linux	Re: 1996 Jeep ChR Lareado Good Afternoon HELPMYJEEP, as you would be aware the booster is simply a large surface area diaphram that uses the engine intake manifold vacuum to create a mechanical advantage over the applied pedal pressure. Your problem description is odd, if we discount the possibility of your having altered the accellerator cabling and possibility of and vacuum leak then it would possibly indicate that the brake master cylinder and diaphram shaft is mis-rigged and you are driving with partial brakes applied. This could be very ungood! When the master cylinder is fitted the actual insertion depth of that push-rod is critical and should not cause any piston movement in the actual master cylinder. I suspect this may be actually happening. You might check the insertion depth that rod actually has, as a rule of thumb when you actually locate the master cylinder on the booster you should feel no active force from that system. Is that booster you have a proper part for your model machine? In many cases that pushrod can be adjusted but you may need the manual for proper adjusting information. Drive the vehicle for some distance without touching the brakes and feel if the disks have any heat. That may give you a clue if the brakes are permanently partially applied. Others will have different ideas. Cheers, qldit.