Visit The Dirt Forum for More Information

Author Topic:   weak breaks, slow pedal return
posted February 09, 2004 12:09 PM
I recently bought a monte carlo and the breaks on it are really bad. They don't seem to have much power break to them and the pedal comes back up pretty slow. If I slammed on them as hard as I could, there is no way I could get the tires to lock up. You can also push the pedal just about to the floor and they dont seem to stop hard. The last owner recently put a new vac booster on to try to fix it but I don't think that helped. Could he have messed something up installing the new booster? The pads and rotors look good.

posted February 09, 2004 12:42 PM
Maybe the system just needs bleeding.

posted February 09, 2004 04:07 PM
More than likely you have air in the system if you have a low pedal line clamp the hoses off then see if you have a pedal if you do then it is air ifyou still don't get a pedal then the master is bad any questions e-me or call 2317236942


posted February 09, 2004 04:08 PM
The low pedal condition could be air in the system,bleed the brakes as allzway suggested.You didn't say what year model we're working with,does it have Anti Locks?If it's just standard brakes then check the vaccum at the booster{should be about 18-20"} and also make sure the in line filter to the booster is'nt stopped up.Is this a RaceCar or street car?This could also be a master cylinder bypassing.

posted February 09, 2004 04:59 PM
It is an 87 monte carlo street car, no abs of coarse. The guy had kind of a mess going on with the carb now that you mention it, i think he said that it isnt quite pulling enough vacuum. It has a road demon 625 which is the wrong carb for this application- he said- and it makes it rich all around and idle like junk. Whole other confusing issue. I guess it is supposed to have a speed demon series for the 226* cam. Anyways, I haven't hooked up a vacuum gauge but if it was a little low-say 10-12 lbs, could that be the problem?

posted February 09, 2004 08:47 PM
alot og guys will say you can't get enough vacume to run power brakes with racingf cams but we have ran all sorts of big lift and dur. cams and still ran the power right now mine is a 510/510 with 244/244 dur and i have plenty of brakes i like to be able to just touch the pedal to get the brakes working not have to push as hard as i can to get them to stop. i'm with everybody else tho you have air in the system could just need bled could be a caliper hanging up or could be a bad wheel cylender on the back if you have drums yet thats what my problem was last year put in a new rear end after mine got bent and just changed shoes turned out wheel cyl's were bad 2 $5 rebuild kits and brakes are fine

posted February 10, 2004 02:16 PM
Bleed them to see if there is air in the system.Remove the lines from the master cylinder and plug it off (the master cylinder)step on the pedal and it should be hard if the pedal moves the master is bad.Check all rubber hoses for restrictions.And make sure that new booster is good.

dan ferry
posted February 10, 2004 08:37 PM
17 i agree with having enough vacuum on a race car but a street car has a few more things using vacuum distributor air bypass valve egr etc and heater and still may get by considering no other leaks are present if the pedal is slow/stiff to push low vacuum if spongy air a carb that is to big should still be able to idle if mixture screws are set.. look for vacuum leaks even though its running rich.

posted February 11, 2004 05:50 PM
What's the best way to check the booster, it does make kind of a squeaking/hissing sound- not from the pedal linkages. The pedal is always hard to push and if i push pretty hard it feels like its bottoms. Like when its dry out, I don't think I could push hard enough to lock em up. There are no other vac. accessories btw.
My gut feel right now is that the carb is way off and messing with the amount of vaccum the motor is pulling. And I probably have either air or a bad booster....or probably all three, haha. Where to start...

Back to the Archives