I replaced the front brake calipers, pads ad rotors on my 2012, 3.7 convert. After bleeding the replaced calipers by having a buddy pumping the brake pedal while I bled the calipers and eventually got a stream of fluid with no air bubbles out of both calipers...and a test drive....I have what seems to be a low and soft brake pedal. Seems like air is still in my system....
So back up on the jack stands and another bleeding session....no air bubbles. The brake pedal still seems low and soft. I do not seem to be getting the full force of brake application to the front wheels. I wonder if the proportioning valve has become upset? I do not see one any where to re-center...WTF? Any help would be welcomed.
The new calipers were installed. Brake fluid was added to reservoir atop the master cylinder.The brake pedal was pumped. Brake pedal held in depressed position. Brake bleeder on r. caliper opened to release air trapped inside caliper. Operation repeated upon L. side caliper. Operation/evolution repeated several times alternating L. to R. until solid stream of brake fluid ONLY...observed exiting both calipers. Brake fluid replaced in reservoir as needed.
Test drive. Brake pedal seemed a bit soft. Brake response on front axle seemed "weak." Bleeding operation repeated upon front axle calipers. No air bubbles observed exiting calipers. Brake pedal still seems "low." Automobile remains on jack stands.
My first impression is that little breaking fluid pressure is being applied to front axle brakes.
1. When replacing the calipers, did the fluid continue to drip from the lines / did the master cylinder ever empty?
2. I forget how the split works in the brake system, especially when factoring ABS, but i believe you need to bleed the whole system and not just the replaced calipers. I always start furthest from master cylinder and move closest, so it would be PR, DR, PF, DF.
How old was the fluid in the car before hand? Did you stop when new fluid came though, or only when no more bubbles were perceived? It's amazing how little air / contaminants actually has to be in there to cause problems.
1. When replacing the calipers, did the fluid continue to drip from the lines / did the master cylinder ever empty?
The OEM calipers were removed for several days before I had the loaded replacements ...in hand...to re-install. So yes probably.
2. I forget how the split works in the brake system, especially when factoring ABS, but i believe you need to bleed the whole system and not just the replaced calipers. I always start furthest from master cylinder and move closest, so it would be PR, DR, PF, DF.
How old was the fluid in the car before hand? Did you stop when new fluid came though, or only when no more bubbles were perceived? It's amazing how little air / contaminants actually has to be in there to cause problems.
The fluid in the Master was OEM It did not look much different than the new fluid that I poured in. There must have been at least a 1/2 pint of fluid pumped through the calipers. I like doing a good flushing... Yep. I know it only takes a small amount of air in the system to create a big problem. I already have new calipers and rotors for the back. IF....I am going to jack the rear wheels off the ground I might just go ahead and replace those calipers etc., as well. At 55,000 miles with new fronts.......Mostly road miles back and forth to Florida and Arizona. Never driven in winter.
Ok, if the master cylinder was allowed to pretty much drain, i would do a full bleed of the system. If that still doesnt fix it, you may have to go to the dealer - or someone with an ABS pump trigger - and have them trigger the ABS pump to bleed that as well.
Either that or stomp the brakes really good when it's wet out haha.
Just went through this ordeal with my 11 GT. Sounds like you may have air in abs in which case your abs needs to be bled. Choices are take to Ford dealer, take out car to grass field, engage abs, or purchase Autel Maxicheck Pro. I purchased the Autel scanner which has abs bleed function, only way I could get firm pedal. And I wouldn't even bother until you finish rear brakes, otherwise you'll have to go through this ordeal a second time.
I will attack the problem again after the holiday. It's time to grill burgs and dawgs...
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