You are as cynical as I am. Smart guy.

 

I say this as the manual does not tell you you can rebuild the solenoids on an automatic controlled air conditioner (o rings $4.00 for 100, takes 4) the manual says to replace complete controller at about $800.00. Typically electronics are ok just the solenoid o-rings are leaking. This fix solves air not switching from floor(default) to dash/defrost etc.

 

I changed everything twice. Fail. It wound up being loose front wheel bearings causing the rotors to wobble and spread the callapers. 1 turn out of adjustment is all it takes. Pedal sinking is normal on 4 wheel disk systems.

 

Outstanding!
I never would have thought of that and it makes so much sense.

Great information!.

Pete

 

Slowly to the floor not normal. I have been corrected. http://sphotos-a.xx.fbcdn.net/hphoto..._4815910_n.jpg

Sinking pedal is not normal with any brake system, but loose wheel bearings as you noted can cause a long pedal, but not sinking pedal. Once the caliper pistons extend all the way there is no reason for the pedal to keep moving.

There are two checks for a master. Plugging the outlet ports if you can find the proper plugs at NAPA and see if the pedal will drop is one, but if the cup sealing issue is deeper in the bore that will not tell the story. A fast hit on the pedal that holds pressure while a slow apply drops the pedal is a better standard, but again not perfect.

Some people who have bought consumer auto parts store M/C have had bad units out of the box. The Motorcraft parts seem to have a better track record.

Another possibility is the ABS unit (both RABS and 4 wheel) bypassing internally. There is a procedure to check the 4WABS in the service manual and noted in my facebook page.

 

does the master cylinder keeps getting low ? it could be the brake fluid is going into the brake booster from a bad rear seal in the master cylinder ! are yiu bleeding the brakes the right way ? start from the right rear, then the left rear, go to the right front then the left front ! did you think it might be a bad proportion valve acting up ?

 

It seems like eons since I fixed this but to the best of my recollection:

(1) I did replaced the MC
(2) I did find plugs and the MC did hold pressure.
(3) I couldn't get the system to bleed. I must have put 3 quarts of fluid through it.
(4) I finally built an ABS bypass unit from fittings, tube, and tees.
(5) Some time during this the new MC (not rebuilt) started to fail. I know that the MC shoots up fluid during part of the pedal push, return cycle. This one started doing it during the wrong part of the cycle.
(6) Replaced the new MC with a newer MC.

I have been running this way for over a year. I found I could put some jumpers in so the ABS light stays off. I have done some test panic stops on snow, ice, and water. The van tracks great. Of course the valve (I forget what they call it) that evens out the front and back is still in the path.

I have the shop manual (CD version) and it doesn't have that ABS test. I wish I knew of it back then. The ABS sits on the shelf in the garage. In order to make the bypass I had to cut off the ABS fittings and put on whatever I could find. Had to buy a $40 double flare tool also.