Question about upgrading vacuum booster

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Pantherfreak

New member
Greetings, folks! I've been messing around with the well-known spongy brake pedal on my '04 MM for quite a while now. I've got SS brake lines, Russell Speed bleeders, bled all corners in every way possible several times, vacuum pump bled, etc., etc. I also brought it into the dealership to bleed the ABS pump, which was not successful for some reason (they said they were unable to fully engage the pump????). In the end, there is still too much pedal movement before the brakes engage. They're good when they engage, but the pedal moves too much before they engage. I've also done the activate-ABS-in-the-rain trick a few times, to no avail. The pedal doesn't drop when I put constant pressure on it, making me think it is not a problem with the master cylinder.

And so, I'm looking to upgrade the booster to an '03+ style. Based on what I've found on this site, there was an upgrade in '03 that provides much better feel. I have an '05 MGM, and can say with certainty that it has MUCH better brake pedal feel - the pedal is always hard, and the brakes bite very quickly every time. Both cars use the same brand rotors and pads, bedded identically, and the calipers have been thoroughly cleaned and lubricated. All the fluid is new Ford DOT 3 as well.

The question I have concerns what else is required for that booster upgrade. I have read a few threads that appear to indicate that a corresponding pedal assembly is also required when upgrading to the newer booster.

Can anyone confirm with certainty that an upgraded pedal assembly is required for this swap or not??

Obviously it would be much simpler to just swap the booster if possible, but any input at all would be greatly appreciated. Thanks in advance, and stay safe!
 
Interesting. I had my booster replaced about 5 years ago, due to leaking and peddle going to the floor. No leak since then, but peddle still goes almost to the floor. Bled them repeatedly over the years, passes state inspection each year, but annoying as a mofo. My 300 will almost throw you out the windshield when you apply yer foot. Granted, it has larger calipers and rotors but the difference is ridiculous. What is the newer booster you mention?
 
From the threads I've read, the booster was upgraded in '03, so any year including and after that. What I've read says that Marauders got the '01-'02 booster, which is described as the reason for many MMs having a less than optimum pedal. The main thread I found was from 05/19, entitled "Spongy brake pedal". A member in that thread stated that he had installed an '03/'04 CV booster into his '04 MM and it greatly improved the pedal feel.
 
Right on, I'd be interested in doing it. Too many butt-clinching moments in stop and go traffic.
 
I would be curious in more information as well. I have an '04 CV LX HPP and an '03 MM and have the same rotors, calipers and pads on both. They both stop the same. If the 04 CV booster is supposed to be an improvement I honestly can't tell the difference. Did the installer do anything else other than booster upgrade?
 
The installer went into some detail about swapping the boosters on his 2 MMs (an '03 and an '04) and that they had both benefitted from the swap, as far as pedal feel. He did perform a big brake upgrade around the same time on at least one of his MMs, but clearly stated that the booster swaps were a definite improvement. After reading the post another bunch of times, I note that he says he may upgrade the pedal assemblies to see if they improve things as well. So, I realize now that he's basically answered my original question - seems he swapped the boosters and kept his original pedal assemblies. So, that will be my plan.

As far as part numbers, I'll post them once I have them - probably by the end of the week. Thanks to everyone for their input!
 
So, I feel like I'm going down the rabbit hole a bit here, as far as part #s I've found so far. The # on my '04 MM booster is 3W33-28195-AB. A Google search on that # turns up almost nothing. I mostly get no results. So I'm not sure I can verify that this is the same as an '01-'02 CV booster, as the OP from 2019 stated.

As far as boosters from '03 and up, I've found 4 #'s so far. I'll attempt to verify these with my Ford parts guy early next week. They all appear to be for an '08 CV, and are still available.

I also found a part # for an '05 that appears to be discontinued. That # is 1W1Z-2005-AA, for what it's worth.

So, lots of searching with no clear results yet. Hopefully I'll have something more useful next week.
 
Well, I learned something today. Didn't really know that the MM got the older style booster, but RockAuto confirms it. The '03 MM booster part numbers all match the 2002 GMQ boosters.

For what it's worth, RockAuto lists the 2003 GMQ booster as Motorcraft P/N 3W1Z2005AA.
 
Oh, that's one of the 4 other part #s I mentioned that I was gonna verify with my Ford parts guy. Great - thanks. One less number to check. That adds some weight to the OP's statement from 2019 about upgraded boosters in '03.
 
Okay, so I've done some more digging with my Ford parts guy, and will break down what I learned from him in relation to the various part numbers I've found online.

3W33 28195 AB - this is the # on the booster on my '04 MM. He was unable to find this # anywhere in the Ford system...I just scratch my head at that one.

F6AZ 2005 B - this appears to be for '95-'97 MGMs and '92 to '06 CVs. That's based on aftermarket web site information, which I can't say is 100% reliable. Those years don't make much sense to me...and it seems to be obsolete, because he couldn't find this one either. More head scratching.

1W1Z 2005 AA/3W1Z 2005 AA - these 2 numbers appear to be for similar parts, which seem to be any and all '03 to '05 CVs and MGMs. And this part is obsolete from Ford.

F8AZ 2005 AA - this appears to be for CVs and MGMs up to '02, but it also came up blank with my parts guy. Another obsolete part??

7W7Z 2005 A - this one came up as a match (finally) for '06 to '11 CVs. I presume it also applies to MGMs, up until whatever year Mercury was axed. This part is available, but the kicker here is the price...my price for this is $450.00 plus tax! And I get a discount because I'm a member of the local Mustang club. Street cost is $520.00 plus tax. Canadian dollars here, but still not cheap in the U.S. For comparison, on the Rockauto website, this part is $340.00 Cdn, plus tax. Still not cheap, but better. My thinking is that since these cars have not been produced since 2011, the prices for certain parts go up. Boosters aren't a common replacement part. One important note - the Ford system doesn't specify this, but the Rockauto site describes this part as "w/o Advance Trac". So ultimately, this part is of no use because MMs have traction control (exclusively, I believe).

So, my thought that this might be a fairly cheap upgrade was incorrect. Some aftermarket prices are well under $200.00, which may have skewed my thinking. But I don't know how reliable any of that information is, because my parts guy couldn't verify the information. I'm thinking that the longer Ford parts are obsolete, the more they get purged from their system. Anything back around the late '90s to the early 2000s seems to just be deleted from their system.

So unfortunately, all this research did was tell me that I can't get this part new from Ford. I'm not sure I trust aftermarket enough to go that route, because sometimes their part numbering isn't accurate. My next route will be a local salvage yard that I've dealt with a lot and trust. Unless I am successful going that route, I guess that's it for this thread.
 
I'm skipping most of the replies as I know most people have never done this swap.

First off, the Part #'s you read on the top sticker of the booster are, I believe, the engineering #'s so sometimes looking those up can be a pain

It is true that the marauders used a 01/02 style vic booster, I could see this happening on early build marauders but I don't know why this was maintained well into 2004. 03/04 vics have a different booster and brake pedal.

You need the 03/04 brake pedal assembly along with the booster, in 03 they changed how the booster mounted to the pedal box. The older style had a 45 degree angle, the newer style went straight. Marauders have the older style

7200164644_4aca50a51a_b.jpg


I am running a 03-04 crown vic booster in my 04 Marauder but partly because I had to swap that when I did the manual conversion. I put the booster from my 04 in my 03 which did help a lot, my DTR always had "okay" feeling brakes but my 03 had the typical "wow these are broken, pedal to the floor" 300A feeling brakes. Made a good improvement with just that swap.

Its interesting your 04 Marauder has "2B195 AB" as the engineering # because my 03 300A had that. My 04 had "2B195 BB". I know a friend of mine with a trilogy marauder which had great pedal feel, I think his booster had "BA" on the end but I don't remember the full #, it was different from mine. I don't have the # for the booster currently on my 04 either.


What I will say though is you're on the right track, if you swap out to the 03-05 crown vic / grand marq booster + appropriate power pedal box, you should get great pedal assist.
 
That clears things up a lot...thanks very much, offroadkarter (the OP I was referring to from the 2019 thread). I didn't know if you were still on the forum. The photo really helps too. I'll be talking to my local salvage yard tomorrow to try and track these parts down.
 
Pantherfreak said:
That clears things up a lot...thanks very much, offroadkarter (the OP I was referring to from the 2019 thread). I didn't know if you were still on the forum. The photo really helps too. I'll be talking to my local salvage yard tomorrow to try and track these parts down.
Click to expand...

I'll see if I can remember to grab the engineering # off my 04 this weekend

Mr. Man said:
So what is it about a brake booster that makes for a better pedal feel? Just wondering,
Click to expand...

I'm far from a mechanical engineer but the booster is the force multiplier for leverage on the brakes. The 98-02 panthers had slightly different brakes, the front rotors were a little larger. I'm not sure if the calipers had different piston sizes or not, if they did. If the calipers changed while the booster stayed the same after the 03+ brake changes, this could explain why the pedal feel changed so much.

I'm not exactly sure what changed in between boosters for 01-02 and 03-05, all I know is they did change.
 
This is interesting, but is it really worth the labor and parts locating? I recently did the Zack big brake swap, did a brake bleed and then went to a shop and got a abs electronic bleed. I gotta say my brakes are rock hard.
 
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Well, eventually I will upgrade to one of the Wilwood set-ups, but I want to optimize what's on the car now before doing that. I will be getting the ABS pump bled again at my cousin's repair shop - hopefully this time, it will be successful. As explained earlier, I went to a trusted Ford dealership to get this done early in 2019, and after returning the car to me, they told me that it "had only been partially successful"...whatever the hell that means. My cousin has all up-to-date Snap-on equipment, so I'm keeping my fingers crossed. I'm looking to eliminate the double pump process I have to follow right now to get the pedal hard. So if these relatively simple upgrades can help, I'm all for it.
 
So just an fyi - I've sourced a booster and pedal assembly for an '03 CV through my local salvage yard for $125.00 Cdn. Seems like a good price to me. I'm getting my ABS pump re-bled next week, after which we'll see how it is. I've also found several videos online detailing how you can adjust the booster pushrod on a Panther, which I was unaware of previously. It looks pretty simple, but there is a warning not to do this unless your braking system is all working properly. So, first I will re-bleed the ABS, and then possibly adjust the pushrod. If all else fails, I'll do the booster upgrade.
 
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