I have a 1999 Volvo XC70. We've just turned over 100,000 miles, but the car looks great and makes me feel safe, after an ugly accident some years back. It's been a summer of expensive repairs, more than the car's market value, I'm afraid, but I'd like to try to get another 100,000 miles out of the car. I have to know it's dependable though--hence the expensive repairs. I teach college and can't be missing class due to car trouble. So, an independent mechanic told me I needed a drive train and a ball joint. Did that, using a rebuilt drive train. The dealership and Midas said I needed a new catalytic converter and another ball joint. Did that. Replaced the back rotors and brakes at Midas, the front ones at the dealership. Started having trouble with the brakes after the back rotors were replaced at Midas. They told me it sounded like the ABS system and I should go to the dealership. The dealership said it needed a brake booster ($900). Did that. The problem is still there--when I push down on the brake pedal, it feels like someone is tapping the pedal from underneath or pushing on the brake so it's hard to push down. Now the dealership says first that I should have the back rotors replaced. I said I did that. Then they said the after-market rotors are probably the problem and I should go back to Midas. I've paid out $4,000 on my car this summer, most of it to the dealership. Anyone have any ideas what could be causing the brake trouble? Am I being toyed with? I have always had my brakes done at Midas and never had trouble before. This is my third Volvo.

 

First, the tapping sound seems to me that the ABS is kicking in , that's not the right time for the ABS to kick in, so something is wrong in the ABS module or the module getting the wrong signals from one the four wheels, you got any codes? Secondly, Did dealer check the vac line between engine and the brake booster? It might cracked or the one way valve is stuck? Did Midas check the rear caliper's pistons are seized or not? All these could lead to hard pushing brake.

 

"First, the tapping sound seems to me that the ABS is kicking in , that's not the right time for the ABS to kick in, so something is wrong in the ABS module or the module getting the wrong signals from one the four wheels, you got any codes? Secondly, Did dealer check the vac line between engine and the brake booster? It might cracked or the one way valve is stuck? Did Midas check the rear caliper's pistons are seized or not? All these could lead to hard pushing brake."

Midas said they thought it sounded like the ABS system was kicking in and told me to go to the dealership. The dealership said if the ABS light wasn't coming on, that wasn't the problem. They said I needed a brake booster, $900. The brakes are still doing the same thing. It FEELS mechanical, as if something is grinding, maybe like it's rusted, and then letting loose. Not just hard pushing, but like gripping and slipping and my husband can hear it too. Sometimes it grips harder than others. If I let up the brake and try again, the brake works normally. Dealership says I'm "getting EVAP codes but that won't affect the way the car drives." I don't know what it DOES affect. I'll ask if the dealership checked the line between the engine and the brake booster. I would think so as they told me I needed a catalytic converter, which is in that area, isn't it? Although they may just have used the diagnostics to know that. But first I will stop back at Midas and ask them to check the calipers, though the rear rotors are new. The problem did start after they were installed and it feels mechanical--my husband thinks so too. Thank you so much for giving me some avenues to follow up on. Have GOT to get this fixed as I'm driving a long way to work each day this semester and don't feel safe. Safety is one of my key reasons for driving my wonderful Volvo.
Thank you again!! I'll post after I see Midas.

 

I do not wish to appear rude but do you know what it feels like when ABS kicks in on severe braking (prior to your current problem)? The reason I ask is that it definately sounds to me like ABS kicking in. Your should feel like a clicking sensation in the brake pedal and what is happening is that the brake is grabbing and letting go so that the wheel does not 'skid'.
Have some one look at the ABS ring around the disc. It is possible that this ring is cracked and this then sends a false signal to the ABS thus kicking in when not required. The crack confuses the ABS because it looks as if the wheel is stopped. If this ring is damaged it is a cheap to replace.