Last week my wife complained that the brakes don't seem as strong as they used to on her CRV. While switching from snow tires back to summer tires on the weekend I decided to try the brakes for myself. They were bad... very soft and the pedal would travel to the floor while the vehicle was running. I almost couldn't get the ABS to engage. So my easter weekend was spent trying to get the brakes back into shape.
Here's a recap of what I've found, fixed and continue to have problems with...
First there is the bleeder screw on the right front caliper that was leaking fluid around the threads when I would open the bleeder. It wasn't a lot of fluid but enough for me to buy a new bleeder screw and install it. No more leaking around the threads.
Next is the fluid itself. The bottom of the master cylinder had some really ugly looking black gunk in it. I decided to replace the fluid and when sucking the fluid from the MC I could only get down so far with the end of the hose. So when I sucked the fluid down to the "MIN" mark there was still some black fluid at the bottom. Seems to me that the only ways to get it out would be to bleed it through the lines or remove the MC. I chose to bleed it through as I have never removed/installed an MC before. Is there another option? Should I remove the MC?
When replacing the fluid I started on the LF then moved through RF, RR and LR as outlined in the bleeding section service manual. I assume that bleeding and fluid replacement should follow the same pattern.
The LF seemed to have endless air bubbles as did the RR. The RR also had a lot of gunk getting pushed out.
After satisfying myself that the fluid had been flushed using a full litre/quart of new dot 3 Penzoil fluid I decided to try them out.
With the vehicle off I pumped several times and the pedal was high and firm. I then held the pedal down and started the car only to feel the pedal travel right to the floor. It was still very soft. I tried pumping the pedal with the car on and again it would travel to the floor.
So I'm now thinking about three possible causes.
1. I didn't get all of the bad fluid out of the lines when doing the flush/fill. Should it take more than one bottle of fluid for a flush/fill? Should I change the order of the wheels?
2. The brake booster is faulty. In my Haynes manual it suggests two tests for the booster. First press the pedal and start the car... the pedal should go down slightly. Mine goes down all the way. Second is to start the engine and after two minutes, stop it and pump the brakes to confirm that they get firmer and higher with each pump. This worked as expected. Could it really be the booster?
3. The ABS system has air in it. Again from the Haynes book I read "On models equipped with ABS it is possible for air to become trapped in the anti-lock brake system hydrolic control unit, so, if the pedal continues to feel spongy after repeated bleedings or the BRAKE or ANTI-LOCK light stays on, have the vehicle towed to a dealer service department or other qualified shop to be bled with the aid of a scan tool". From what I've read on these forums I should be able to address this by activating the ABS from a few hard stops. Is that correct or should I be towing the car to the dealer for the scan tool treatment?
If there are any suggestions or ideas I would be grateful.