October 26, 2021, 04:45:02 AM

Author Topic:  Did the 2013+ brake upgrade... Issues...  (Read 212 times)

Offline LMKS012

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Did the 2013+ brake upgrade... Issues...
« on: September 17, 2021, 01:51:41 PM »
Hey guys, I just got done last week doing the 2013+ large brake upgrade to my 2012 Lincoln MKS.

I love the car and had Powerstop rotors/pads/calipers on it prior and it still sucked in the stopping department.  Also the groaning when you hit the brakes hard vibrated everything in the car something fierce.

Well, about 2 years ago I picked up a 2017 Lincoln MKT Town Car.  It has the big brakes that they switched to in 2013 and was everything I was looking for in the brakes for the MKS, so I resigned myself to doing the upgrade as soon as I needed to do brake pads on the MKS.

About a month ago I just got done replacing the expansion valve because it froze up (somewhat common I heard on my vintage MKS) along with the filter/drier (why take a chance), as well as doing a spark plug change while I was at it.  That afternoon, after picking my daughter up from college, wouldn't you know it I get a solid metal-on-metal grinding when I brake.

Get it home, all the pads everywhere are good except for the passenger rear and the pads are both gone, inside and out.  Something happened and the caliper must be bad since all the rest of the pads on the other 3 wheels have at least 70-80% of their life left.

So, I take this as a sign, go and order up all new powerstop brakes front/rear for the 2013+ setup.  Couldn't find them in stock anywhere else but JEGS for the fronts and I had to piece together the rears (ordering calipers/rotors/pads all seperate), so I ordered everything via Amazon to save on shipping.  I ordered up a brand new master cylinder and brake booster from RockAuto (shipping took forever because FedEx is majorly having problems).  I also picked up new brake hoses front/rear from local dealerships.  Got everything in and planned out how I wanted to attack things.

I decided to use DOT 4 LV brake fluid, since I am going to be doing a full flush/fill of the entire system, and since I am doing that I decided to pickup a FOXWELL NT630Plus scantool to be able to bleed the ABS unit as well (I also picked up a vLinker FS USB to be able to use FORScan as a backup).  The rest of my supplies included 6 liters of Pentosin DOT 4 LV fluid, as well as my fairly extensive existing toolset (including a vacuum bleeder setup).

So, to start with I put the car up on jackstands, pulled the tires, pulled the intake/battery & tray, opened a rear bleeder, drained the entire brake system of fluid, did the same at every caliper, pulled the brake lines off the master and the ABS unit, pulled the ABS unit, pulled the booster and master cylinder as a set.

I then installed the new booster, installed the master cylinder, installed the two main brake lines off the master after bending in the new angles, hooked up two hoses to the ends of the two lines and bench-bled the master cylinder in place.  After about 15 minutes I noticed no new bubbles for a few minutes, figured it was bled properly, put some vacuum caps on the lines, installed the ABS unit, left all the lines disconnected and moved onto the rotors and calipers.

Now, since I am overly cautious and didn't want to have to worry about going out and buying parts, I had already ordered up a pair of Motorcraft OEM hubs to have on hand.  Since I was installing new rear splash shields, the service manual calls for pulling the hubs to get it accomplished and I have ZERO faith that if a hub is a PITA to remove that it would be reusable.

Well, wouldn't you know it the first hub I try to pull brakes the cheapo Harbor Freight slide hammer axle puller bracket, so I have the wife go get me a Craftsman slide hammer from Lowes.  After using that for an hour, I call it quits, and just pull the kncukle.  Wasn't bad at all considering there are no ball joints to split.  I have a 20 ton press in teh back of the garage, so I go press that hub out.  Lets just say I thought I was going to break the press getting it out.  That sucker released with a massive BANG!

Cleaned it all up, got it all back together, had to pull the hub twice more because I kept forgetting the damn splash shield (that is what happens when you get distracted by having to make dinner and when your wife is talking to you while you are working), got it all back together finally and then went to put the new brake hose on.  Unbolt the original hose and wouldn't you know it, the factory overtorqued the fitting so badly it mushroomed the end of the nut where it had to be filed down to get it in the new hose end.  Another 2 hours there...  Probably took me at least 6 hours on that one corner alone.

Long story short, the other side had all the same issues (hub had to be pressed out of the knuckle, brake hose nut was mushroomed) but since I did it all before on the other side, this time I had everything done in about an hour and a half.  And I didn't forget the splash shield at all, so that was a one and done situation.

So, then I move to the fronts, everything is going great on the first side, brackets all off, hose unbolts and the line nut is not mushroomed, and all of a sudden I go to remove the splash shield and only the center top one comes out nicely.  All three of the other ones are not blind holes, but are exposed to the elements on the backside... So, I get the top bolt out by rocking it, yet the bottom two bolts both shear off.  ARGH!!!

Out comes the drill, bits and a helicoil kit...   I drill them out, helicoil, have my oldest son find some useable fasteners in my collection of old bolts and get that side done.

Move to the last corner and it is a 100% identical to the opposite side.  Go through the whole thing again, luckily I had on hand pairs of the same fasteners to replace the broken ones.

At this point I am kinda shocked it was all as hard as it was, given that my car only has 84k miles on it, I drove it only through 2 winters (previous owner only owned it a single year/winter) as it was garaged until 2 years ago.  It is always car-washed before being parked and virtually every single bolt on the engine/suspension all comes apart with no, I mean absolutely no corrosion anywhere (the rear knuckles and hubs fasteners all came right out by hand after I released the torque on them).

So, at this point I feel pretty good about things and remember I have a set of belts to replace the original OEM factory ones, so I put those on right away.

Now we move onto the bleeding the brakes.

I finally hook up the lines to the ABS unit, get it all tightened down, then fill up the extra reservoir bleed container (makes sure the master cylinder doesn't go dry), get that mounted on the master and opened up, then I move to the passenger rear caliper, open it and start pulling a vacuum on the vacuum bleeder.  I get that side filled with extra fluid coming out for a good 30 seconds, tighten it up and move to the drivers rear caliper, do the same there, then the passenger front caliper and finally the drivers front caliper.  At that point I figure the system is entirely filled, so I go back to the passenger rear and do that until I don't see any bubbles, and repeated that in the same sequence until all 4 corners are bled.

Then, since I had the ABS unit disconnected I followed the procedure with the scantool to bleed the ABS unit.  I hookup to the left front caliper (drivers front) and do the bleed procedure, again with the vacuum bleeder, but this time pressing in two second intervals as the scantool instructs you to.  I repeat that in the sequence it wants (left front, left rear, right rear, right front), and then after it says it is complete, I go back, connect up to the passenger rear (right rear) side with the vacuum bleeder, open it up and proceed to bleed that corner while actuating the parking brake as instructed in the service manual (the rear calipers parking brake system has extra passages inside of it that can trap air so you have to actuate the parking brake 5 times while bleeding).  After I get no more bubbles, I move onto the drivers rear caliper (left rear) and do the same.

At this point I have gone through about 3.5 liters of brake fluid.  I check and the pedal seems solid with the car off.  I get the battery tray/battery/air intake all back together and start the car.  No lights or anything, but when you press the brake pedal it drops down a lot further.  Pumping doesn't really seem to make it any stiffer and it almost goes to the floor (not quite and I visually confirmed that the calipers all actuate completely).  Overall the pedal feel with the car running is soft and spongy.

So, I go back and rebleed the system using the ABS procedure.  This time with the car running.  I get a couple of larger bubbles out of the drivers front, and a few small ones out of the rear calipers, but nothing out of the passenger front except for straight fluid.

At this point I am almost out of brake fluid, the peddle does not feel any better, so I call it a night.

The next day I pick up 3 more liters of brake fluid, and go through the whole bleed procedure again.  Now, the one observation I will make is that with vacuum bleeders you normally get a lot of air getting past the threads in the bleeder screws, so I use grease and dab it one the threads of the bleeders until the excess air infiltration stops.  In doing that on the fronts it works great and you don't get any sort of air bubbles at all.  But opn the rears I end up getting a buildup of micro-bubbles on the inside of the bleed hose.  This even happens after sitting for an extra day.

So, I did all of the ABS unit tests and it seems to test out fine, was working just fine before I started this and via pedal you can tell each and every valve opening/closing/pump actuation and block/release there is, so I highly doubt the ABS unit spontaneously "failed".  But, I am questioning the master cylinder.  The pedal is rock hard with the engine off, but will easily go down and be spongy with the engine running. 

I did take it out later in the evening and "bedded" the new brakes in when there was little traffic around.  I wanted to see if bedding them would make a difference.  The brakes bedded in fine, good braking at the bottom of the pedal throw.  All 4 calipers reacted properly, but the pedal "feel" didn't change, as it is still soft and spongy.

Now, I stated I purchased a brand new master cylinder through RockAuto.  Here is the issue.  It came with the Motorcraft box that had the seal cut open, then it was resealed with clear packaging tape (Motorcraft uses brown paper-tape) and it had a green "INSPECTED" sticker on the outside of the box.  I am just wondering if someone didn't buy one, test their issue with it and then package it back up and send it back as "unused".  It would make sense then that RockAuto "inspected" it physically, put a sticker on it and sent it out because "it looked good".

My concern is that if someone actuated it without fluid in it that one of the internal seals is compromised and is allowing air in somewhere.  Needless to say, I have so little confidence in the "INSPECTED" aspect that I went out and bought a brand new one at a local Ford dealer and that box is intact and factory sealed.  I will pull the other one and send it back to RockAuto for a refund since it is highly questionable and everything is pointing to a bad master cylinder, so at this point I am going to consider it defective out of the box.

So, my next step is to pull the "bad" master cylinder, cap the lines at the master, install the new one, hookup a new Dorman master bleeder kit (two clear lines, plastic fittings and hose holders for the reservoir), fill the master, bench bleed it in place until there are no bubbles and then for an extra 15 minutes, just to be sure.  Then I will open up the two main lines at the ABS unit, hook up the two lines to the master, bleed out the air at the ABS unit, tighten them down, then go through a complete set of bleed cycles once more, including a manual vacuum bleed, then a scantool actuated ABS bleed, then the parking brake actuation bleed of the rears and finally a last regular bleed to verify there is no more air in the system.

Does this sound reasonable?

Do I need to actuate the brake pedal as part of the scantool ABS bleed procedure if the vacuum bleeder is pulling fluid through the system?

At this point I have gone through 9 liters of brake fluid.  I just purchased another 5 liter bottle to finish it off.

I plan on doing all of this after I get in the new rear shocks on Saturday (when I pulled the knuckles I noticed fluid on the outside of both rear shocks and the drivers side did not extend on its own when I unbolted it to pull the knuckle, so they need to be replaced).

I have never had this kind of issue trying to bleed a brake system.  Then again, I never had an entire brake system run dry.

Any and all suggestions are appreciated.
« Last Edit: September 17, 2021, 01:55:32 PM by LMKS012 »


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