# Spongy Brake Pedal - Cannot Diagnose - 2014 Q5 TDI



## jpeterferrell (Jan 26, 2015)

I recently purchased a used 2014 Q5 TDI. I've owned lots of cars in the past, worked in auto shops for years growing up, and have a routine whenever I pick up something new - do the maintenance I can guess probably wasn't done by the previous owner. When I got the car, the brakes felt spongy to me. No problem - just bleed the system. I have a Motive Power Bleeder and have used it for years on a number of vehicles. I thought this one would be no different. I pulled the wheels, hooked up the pressure bleeder, and went to town. I actually bled twice - once following the Bentley manual bleed order (FL, FR, RL, RR) and once using the traditional bleed order (RL, RR, FR, FL). I got quite a bit of air out of all of the bleed screws, but I let the power bleeder run until I was sure I was getting nothing but clean, new fluid. I probably ran...2-3 quarts through the system.

Back in the car...pedal is still spongy. No problem - I'll bleed it again. Did the same process again. No difference. I have a VAGCOM, but wanted to avoid doing the ABS bleed procedure since I can't seem to find any one guide to it that offers clear, comprehensive steps. I know I didn't let the reservoir run dry when I was bleeding it (I always keep the power bleeder with ~1-1.5 quarts in the reservoir). I have bled to the point where no more air is coming out.

When I say the pedal is spongy, I don't mean that it lacks stopping power. It can stop the car fine. But for the first inch or so of pedal travel there is no resistance at all, then some, then slightly more, then I can feel the pads biting down, but the pedal never really has that same "strong" feeling you get with a properly bled hydraulic system. Am I missing something here? Could it be something else wrong with the brakes I'm just not noticing? The pads have plenty of life left on them, the rotors appear fine, the lines are fine. The system pressurizes fine - no leaks. The rear calipers are rusty as all hell, but I don't see how that could cause this issue.

Am I doomed to spend every Saturday morning trying to bleed these damn brakes? Or do I need to seek professional help? Or am I just expecting too much of the Q5's brake system? My wife's 15 Touareg TDI brakes feel MILES different from these...I can't imagine that Audi would have it feel this way stock...

Any help?


----------



## A3REDT (Mar 22, 2014)

Given that you haven't bled the ABS I would recommend engaging the ABS on a stop and seeing how the brakes feel immediately after that. If the brakes feel better you should probably then bleed your ABS. I know the procedure for my mkV but I'm sure yours is different so I can't help you there. Generally you can click through the procedure in VCDS without doing the screws and such to get a feel for what you should be doing.

Also would be interested to know what brakes the Q5 has vs the Touareg. Calipers vs master cylinder size can make a big difference in feel.

How do the brakes feel with the car off after a few presses to empty the vacuum reservoir? I think the newer Audi's can have a strange pedal feel from the emergency brake assist system that's built into the vacuum reservoir.


----------

