Thread: Front brakes dragging

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The 7" dual has worked great now for several weeks without any problems but it just doesn't have enough boost for my application. I did get an new 8" dual yesterday from skipwhiteperformance.com with a 10 year warranty, these guys have great products and the best customer service I ever dealt with.

1999 Chevrolet Suburban
As I use my brakes the pedal height gets higher. If I use the breaks hard the right front caliper locks. It started when I was using the brakes to slow down turning in my driveway. I had to use a lot of power to get in the driveway because the right front wheel is turning slower and the antilock brakes were pushing back. It happened again yesterday when I was far from home. I drove to autozone with the wheel smoking and purchased parts and changed the caliper in the parking lot. It started draging again as I was driving each time I had to use the brakes the brakes draged more. I pulled off the highway, as I resumed driving I could hear the R. F. tire scrubing and smelled tire smoke. I touched the brakes a couple times and it got somewhat better. This is the 3rd replacement for that caliper. Can this be the antilock brake controller????
Comments please

I installed a new 8" dual this weekend and it works great, no more problems with dragging brakes.

There's not much difference between a 7" and 8" when just slowing down but there's a big difference during an emergency stop, the 8" requires less than half the pedal effort. The 7” did not respond to pedal input as quickly it’s kind of sluggish, I’m not sure all applications would be the same at least in mine the 8” is a better choice.

Well I spoke too soon, the new booster is starting to do the same thing after everything reaches operating temperature, this booster came from a different supplier but looks exactly like the first one. I took the first booster apart and found that the problem maybe a seal between the two stages it sticks and no amount of lube helps.

Most of the internals on the aftermarket 7" and 8" dual boosters are plastic, never taken any other boosters apart maybe they're plastic to, I'm not that crazy about depending on plastic to stop my car.

I have a 7" dual that functions correctly but does not have enough boost. I'm going to the part store to pick up a C3 Corvette 9" dual but I don't think there's enough room.

Originally Posted by jayd

Well I spoke too soon, the new booster is starting to do the same thing after everything reaches operating temperature, this booster came from a different supplier but looks exactly like the first one. I took the first booster apart and found that the problem maybe a seal between the two stages it sticks and no amount of lube helps..

I thought the part you bought came with a 10 year warranty? Taking it apart probably just voided any chance of returning it.

I took the first one apart not the one with the warranty, will be sending it back tomorrow.

Just finished installing a C3 Corvette 9" booster, still have some adjustments to make but it works well. This is a rebuilt Delco style with a lifetime warranty.

The 8" had a better feel but a little less power than the Delco 9". The Delco will lock them up but it's a little less responsive, would have to change the pedal ratio to fix that.

Originally Posted by jayd

I took the first one apart not the one with the warranty, will be sending it back tomorrow.

Just finished installing a C3 Corvette 9" booster, still have some adjustments to make but it works well. This is a rebuilt Delco style with a lifetime warranty.

The 8" had a better feel but a little less power than the Delco 9". The Delco will lock them up but it's a little less responsive, would have to change the pedal ratio to fix that.

Hey!! I noticed that you have a pedal assembly under the floor! Do you have a residual valve(2psi for disc and 10psi for brum) in the line to the front brakes? Pete

Originally Posted by jayd

I took the first one apart not the one with the warranty, will be sending it back tomorrow.

Just finished installing a C3 Corvette 9" booster, still have some adjustments to make but it works well. This is a rebuilt Delco style with a lifetime warranty.

The 8" had a better feel but a little less power than the Delco 9". The Delco will lock them up but it's a little less responsive, would have to change the pedal ratio to fix that.

Hopefully this "journey" has reached a final and satisfying conclusion! Now on to other pressing matters! What's next???? 8-)

I still have a problem, the C3 booster requires mores pedal effort than the 8" and it's a 9" dual. When I went from a 7" dual to an 8" dual the pedal effort was just about right but it took a lot of pedal effort to get lock-up.

The C3 requires a little more pedal effort for basic stops and slowing down but will lock up with less pedal effort.

Is it the level of vacuum?