Questions and Answers

Chevy Chevelle Has Brake Problems Q. Hello, the brakes were feeling a little sluggish when I parked the car eight months ago. The other day I pulled it out of the garage and put the battery back in it, checked all the fluids and tire pressures and started it up. To my surprise, I had no brake pressure at the pedal, went all the way to the floor and brake light came on. I turned the motor off.

I figured I got some moisture in the lines so I bled the system and replaced all the fluid in the process. With the motor off, I now had plenty of pressure at the pedal. Once I started the motor, I had nothing!

My local shade tree mechanics said it was my master cylinder so I replaced it. Still no pressure, but the funny thing is with the motor running; no pressure at pedal, if I disconnect the vacuum fitting from the booster I have pressure at the pedal.

I capped off the vacuum lines and backed out of the drive way and to my surprise; no brakes. Before I start changing every part in the system, I was hoping somebody else has come across this mess before. My next item on the list is my power booster. Help!

• 1970 Chevy Chevelle
• H.O. 350 4B (19 psi vacuum at idle)
• Auto transmission
• Power brakes (front disks, rear drums)

Ruben

A. The "booster" is a vacuum assist device. It magnifies or intensifies the foot pedal pressure and passes it along to the master cylinder. With no vacuum to the booster, the pedal should be very hard feeling and hard to stop car, but it should stop, just will need a lot of pressure from your feet.

If the pedal is hard but won't stop car, you will need to jack up car and see if any wheels stop when pressing down on brakes. You may have frozen brake calipers in front or frozen wheel cylinders in rear.

One thing to try, clamp off the front brake lines and try it. If the pedal stays hard then you need to replace the front brake calipers and brake hoses.