Friend of mine is having the strangest brake problem. He has replaced all the lines, master cylinder, booster etc. Brakes bleed fine. Problem is. When your driving the car and step on the brakes.. It feels like there is a brick under the pedal. The pedal just doesn't go in far at all. The car does stop. But it just isn't safe. Any suggestions???

Thank You
John

Ever Since I have had my Chevelle the Pedal has been firm... With little travel, but it stops on a Dime....

Why do you say it's not safe? :confused: As long as the brakes work and stop the car without effort, that is what it should be like. Sounds like he's just not used to the benefits of a good brake system yet.

I have seen bad power boosters do that,low intake vacuum at idle/low speeds due to long duration per cams,and vacuum leaks.

If your running a perf cam check your idle vacuum and if it's below lets say 13-14 inches @ idle this could be your problem.

If you find low vacuum check to see if your running enough inital advance because many people do not run enough intial advance with aftermarket perf cams which leaves the intial timing too retartded which in turn causes lower idle/low speed vacuum.

You should be running approx 15-18 deg intial advance with an aftermarket perf cam so try that setting if you have low idle vacuum & are running less than 15 deg btdc intial timing at this time.

If it's not low intake vacuum due to retarded timing it could be low intake vacuum due to a large cam/very long duration and in thzat case you will neen a reserve vacuum canister.

If it's not due to any of the above have your power booster checked and if that checks out ok then check for bad vacuum check valve in vacuum line going to booster.

If thats allok check for a vacuum leak but i doubt it's that because it would need to be a fairly big leak that would in turn be easy to hear and would affect the running of the esp at idle & slow speeds which you should be able to notice.

Even though you have new brake system it could still be a defective master or brake booster so keep that in mind too.

Scott

Could it be that he is just used to the feel of the spongy peddle that he used to have?? My 69 has a firm peddle too, but they work great..

Why do you say it's not safe? :confused: As long as the brakes work and stop the car without effort, that is what it should be like. Sounds like he's just not used to the benefits of a good brake system yet.

He doesn't feel safe driving it. I guess he just isn't used to so little travel in the brake pedal.

I have seen bad power boosters do that,low intake vacuum at idle/low speeds due to long duration per cams,and vacuum leaks.

If your running a perf cam check your idle vacuum and if it's below lets say 13-14 inches @ idle this could be your problem.

If you find low vacuum check to see if your running enough inital advance because many people do not run enough intial advance with aftermarket perf cams which leaves the intial timing too retartded which in turn causes lower idle/low speed vacuum.

You should be running approx 15-18 deg intial advance with an aftermarket perf cam so try that setting if you have low idle vacuum & are running less than 15 deg btdc intial timing at this time.

If it's not low intake vacuum due to retarded timing it could be low intake vacuum due to a large cam/very long duration and in thzat case you will neen a reserve vacuum canister.

If it's not due to any of the above have your power booster checked and if that checks out ok then check for bad vacuum check valve in vacuum line going to booster.

If thats allok check for a vacuum leak but i doubt it's that because it would need to be a fairly big leak that would in turn be easy to hear and would affect the running of the esp at idle & slow speeds which you should be able to notice.

Even though you have new brake system it could still be a defective master or brake booster so keep that in mind too.

Scott

Thanks a bunch Scott.. I will pass on this information. Much appreciated.

Friend of mine is having the strangest brake problem. He has replaced all the lines, master cylinder, booster etc. Brakes bleed fine. Problem is. When your driving the car and step on the brakes.. It feels like there is a brick under the pedal. The pedal just doesn't go in far at all. The car does stop. But it just isn't safe. Any suggestions???

Thank You
John
John just went through a problem with my chevelle in that I was given a drum brake master by mistake and I am running disc brakes up front cause the pedal to be stiff and also cause the brakes to stick a little in the front I found that the drum brakes cylinder masters hold some pressure since they are slower reacting then disc not sure if this is your problem or not but something to look in to!

He doesn't feel safe driving it. I guess he just isn't used to so little travel in the brake pedal.

That's exactly what I was thinking. So does the car stop ok?

I have seen bad power boosters do that,low intake vacuum at idle/low speeds due to long duration per cams,and vacuum leaks.

If your running a perf cam check your idle vacuum and if it's below lets say 13-14 inches @ idle this could be your problem.

If you find low vacuum check to see if your running enough inital advance because many people do not run enough intial advance with aftermarket perf cams which leaves the intial timing too retartded which in turn causes lower idle/low speed vacuum.

You should be running approx 15-18 deg intial advance with an aftermarket perf cam so try that setting if you have low idle vacuum & are running less than 15 deg btdc intial timing at this time.

If it's not low intake vacuum due to retarded timing it could be low intake vacuum due to a large cam/very long duration and in thzat case you will neen a reserve vacuum canister.

If it's not due to any of the above have your power booster checked and if that checks out ok then check for bad vacuum check valve in vacuum line going to booster.

If thats allok check for a vacuum leak but i doubt it's that because it would need to be a fairly big leak that would in turn be easy to hear and would affect the running of the esp at idle & slow speeds which you should be able to notice.

Even though you have new brake system it could still be a defective master or brake booster so keep that in mind too.

Scott

Well.. So far he has tried all the above and no luck.. Only thing left is changing the master cylinder and power booster. That's his next step. Much thanks for the help

That's exactly what I was thinking. So does the car stop ok?

Yep it stops. But he don't like the way it feels. Oh well.. We'll see what happens when he changes the cylinder and power booster again.