Help Brake Pedal Hard to stop

[Ron Bearden]

Help, My brake pedal is feels hard, and it takes more pressure to stop. I have checked the vacuum pressure at the booster pump and it has plenty of vacuum. This 94 is driving me crazy. I am beginning to think it may have been a lemon. Any help from you guys would be very appreciated..

 

[grapeknutz]

Could it be the pistons inthe caliper are stuck as in rusty?

 

[USRobo]

When was the last time you changed your brake fluid? I had the same problem with my 93 and I just changed the brake fluid this week. It was brown instead of clear. Once I changed the brake fluid the brake pedal became normal again.

Try that before you spend a lot of money changing parts. Brake fluid is only $10.

 

[trrgod]

Probably it is either the master or the slave has gone out. Check it out. Best to replace both at the same time. Usually if you just replace one the other goes out after awhile. That's what happened to me. First the slave then a little later the master. Triple check that the booster is working right, when mine went out the pedal was hard as hell.
As far a it being a lemon, they all have therse problems. I had an 84 and now an 89 and things go out all the time. I am just used to it. My 84 was worse because the parts that went out were very expensive. The rack and pinion and the transmission (twice). Since I got the 89 it seems more normal things quit on me. Starter, alternator(twice), various sensors, cat and pre cats, o2 sensor, injectors, batteries(2), clutch, brake booster, master and slave, seat motors, seat foam and leather deteriorated-so new seats, door and hatch seals need replacing, throttle body needs replacing(shaft is worn and air is leaking in causing idle problems, egr(twice), fuel pressure regulator(twice), various relays, neutral start switch at clutch pedal, brake light switch, outer window seals(both L and R), bose radio going out needs new amps and head unit tune up, window switchs, winshield washer switch, AC clutch, AC contro unit, HEATER CORE (I did this myself------never again, almost killed me and took ALL day), needs new shift lever boot(leather is deteriorating), E brake mechanism replaced, needed new distributor and module and pickup and pig tail, had to have Bilstein rebuild my FX3 shocks($100.00 each) and now one of them leaks and needs rebuilding again, FX3 selector needed replacing, relays in the ABS syster went out, and some other stuff needs fixing now.
I got the car with 44 thousand on it and it has a little over 125,000 now. I have enjoyed every ride I've had in it and still today love to drive this car. It handles like a go kart and has the pick up my 66 GTO did. Did I mention that I love this car?

 

[trrgod]

I forgot to mention a few things.

Needed a new MAF sensor, air filter housing(cracked at seam), fuel pump and screen, had to replace the bulbs in the instrament cluster and had to have the intake manifold gaskets replaced because of infamous coolant leakage at rear of manifold.

I love this car.

 

[c4cruiser]

While you may have sufficient vacuum at the hose going into the brake booster, the booster itself may be the problem. An excessively hard pedal is usually indicative of a bad booster. Do you hear any hissing sound as you apply the brakes? Open the hood and let the engine idle. Have somebody depress the brake pedal and listen around the vacuum booster for any hissing sounds. This would indicate a vacuum leak inside the booster.

The GM Service Manual has a rebuild procedure for the vacuum booster, but it would be easier to replace it. Also there is a vacuum check valve where the vacuum hose attaches to the the booster. That valve can go bad, keeping vacuum from entering the booster diaphram.

You should definately check the brake lines, connections and around the calipers for any indication of leakage. A fluid flush is something that should be done every couple of years anyway so it's cheap insurance.

If you suspect a bad (stcky) caliper, that can show up as either much hotter or lower temps at a particular rotor. I would also expect the Service ABS light to come on if there is a sticky piston in the caliper.

 

[trrgod]

I forgot a few more things.

Radiator(twice)
water pump-3 times (I now have one from HI-FLOW, has lasted years)
Head light motors,both L and R- repaired myself with the bushing kits
Hood hinge on passenger side broke- replaced
plastic Vaccum lines under plenum broke- replace with new ones
all water hoses several times- including ones at throttle body and oil cooler
Oil cooler hard line- it rubbed against the frame and wore a hole in it-replaced

There is no justification for all these repairs needing doing except-----------

I love this car!

 

[Ron Bearden]

Thanks for the info, It is appreciated. I will let all of you know exactly what it is once I find out. I too am pretty sure that it is the brake booster.. Thanks again.