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Discussion Starter · #1 ·
Brake booster will not come out; hits strut tower!

Hi all.

I've found two other threads on this exact issue and no answers. I need to remove the brake master cylinder and booster from my '96 Cobra. No way will the bolts on this thing clear the firewall, because the front of the booster hits the strut tower. I have pulled up on it as hard as I can, trying to tilt it up away from the strut tower, but nope. The bolts will not clear the holes.



I don't think the master cylinder has anything to do with the obstruction, but it doesn't matter because the two can't be separated while installed (contrary to many instructions I've seen). Why? Because on my car, the bottom bolt holding the master cylinder to the booster is tucked underneath the booster facing the firewall. I can just get my arm between the valve cover and booster to hang a ratcheting box-end wrench on that bolt, but there is no way to move the wrench. Pictures attached.




Anybody know how the hell to get this thing out? Thanks!
 

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Because on my car, the bottom bolt holding the master cylinder to the booster is tucked underneath the booster facing the firewall. I can just get my arm between the valve cover and booster to hang a ratcheting box-end wrench on that bolt, but there is no way to move the wrench. Pictures attached.
At the risk of missing the obvious, will a socket on an extension long enough to extend the ratchet wrench beyond the end of the master cylinder? May be necessary to use a flex socket to improve access.

FWIIW, the Ford Service manual does show removal of the master cylinder before removing the hydro-booster.
 

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Discussion Starter · #4 ·
At the risk of missing the obvious, will a socket on an extension long enough to extend the ratchet wrench beyond the end of the master cylinder?
Thanks for your reply.

Unfortunately, NO, because the bolt is facing the firewall, not the front of the car. And opposite the bolt there is the body of the booster. Thus, the bolt is essentially facing sideways in a recess, where there is no access to it except from the side (where my arm is in the picture).

Also, it appears to be the booster that's hitting the strut tower, so I don't see how removing the master cylinder will help. I just pulled up the Ford service manual, and it says the two are removed as a unit: "Inside the engine compartment, move hydro-boost power brake booster and brake master cylinder forward and up until the booster studs clear the dash panel. Remove from vehicle."
 

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OK. This thread has me somewhat confused because I have changed a master cylinder in a 1996 GT. Granted it's a GT and honestly it was a long time ago. But I did look at the master cylinder on my 2000 GT and the bottom bolt that connects the master cylinder to the hydro-boost faces AWAY from the firewall. Where as the top bolt faces towards the firewall.

In your case it would seem that perhaps someone installed the bottom bolt holding the master cylinder on backwards.

It also occurred to me that it might be possible to remove the master cylinder and then remove all of the bolts between the two halves of the hydro-boost unit. Thus partially dis-assembling while still in the car. I'm sure this will be a huge mess.

But perhaps another experience I have had with my 1996 GT could help. This was my first Mustang and I didn't know much about it. The car was very rough when driving. With the help of a mechanic it was determined the motor mounts were BROKEN.

Here's where the story could have some bearing on your problem. I noticed that after new motor mounts were installed the motor sat much higher in the K-member. So much so that there was little clearance between the strut tower brace and the top of the motor. Before there was several inches of clearance.

Is it possible that this motor is setting lower in the K-member and that is making it harder to service things than would other wise be the case?

I know that Mustangs are very hard on motor mounts. It's why it's a good idea to replace anytime the motor is removed.
 

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Discussion Starter · #6 ·
Thanks for that info, and interesting observation about the motor mounts. Mine have been replaced fairly recently, and the one I can see on the relevant side looks OK.

Also, the brake booster is only mounted to the firewall, independent of the engine position; it collides with the strut tower and looks as though it would do so even if no other parts (even the brake cylinder) were present. Of course this makes its original installation a mystery too.

It's also mysterious how you could unscrew the brake cylinder from the front of the car. From this picture and my observations, I don't see how the bolt can be unscrewed from that direction:
 

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I have a set of "stubby" wrenches that will sometimes get into tight spaces that other wrenches can not. In this case put the stubby on horizontal and wrap a strap around to pull up on the wrench. This will give a way to make up for the lost mechanical advantage of the short wrench.

I also have a set of "S curve" wrenches that sometimes does the trick.
https://www.harborfreight.com/catal...,EAFeatured+Weight,f,Sale+Rank,f&q=s+wrenches

When things get real serious there's always a "crows foot". This will let you extend the socket to turn from the front. I have to say the times I have had to use a crows foot have been some of the hardest bolts to remove I have ever dealt with. Perhaps the crows foot can "break" the nut loose and then fingers do the rest.
Sears.com

Another option is an "indexed" ratchet.
https://www.harborfreight.com/38-in-drive-indexable-head-ratchet-62316.html

I suspect that once the master cylinder is off you will see that it is possible to reverse the bottom bolt of the master cylinder so that next time it's not quite so hard.

Also consider that IF the master cylinder were removed that it might be possible to first lower the hydro-boost unit and then turn 90 degrees and lift up to clear it from the car (avoid the strut tower all together).

Finally there's the option to disassemble the hydro-boost in the car. Again more likely to be done after the master cylinder is out of the way. I'm sure this will be messy as well have it's own set of problems getting the new unit back in.

Good luck.
 

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Discussion Starter · #8 ·
Hey, thanks for those tool references! I was wondering what kind of tools might be out there for this type of thing, but without knowing their names it's hard to search for them.

I have to admit that I don't see how the crow's feet would be an advantage in this situation; the one video I watched about them involved torquing a nut on a bolt that had a hex socket integrated into it (on a motorcycle). However, these might be the best thing for removing the lines from the top of the proportioning valve; looks like the lines are going to block access to the nuts.

I'm going to pick up that indexing ratchet wrench right now, though! Cool!
 

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Discussion Starter · #9 ·
@wmburns Got it out!

First of all, the crow's feet were a great help. The first thing I did was use one to disconnect the master cylinder from the proportioning valve.

I used another to loosen the power-steering lines from the hydroboost... well, two of them anyway. I didn't realize the larger one was threaded in reverse in regard to the others, and cursed mightily as I tried to "loosen" it. Once I actually fully unscrewed the other two and saw how these fittings work, I realized the larger one (although a different design) was oriented in the opposite direction. Plus, with the other two lines actually disconnected, I was able to brute-force the entire mess out of the firewall and clear of the strut tower at last! This gave me access to the problematic final nut with yes, a new stubby wrench that broke it loose.

So I've already used two of your tool recommendations to great advantage! I haven't used the indexing ratchet wrench yet, but it sure is cool anyway. Thanks again!

The next thing I did was separate the booster and master cylinder. I'm still perplexed as to the source of the fluid that's all over the rubber boot on the booster. It must be brake fluid because it's not red (the power-steering fluid is obvious), but the port where the booster joins the master cylinder isn't wet with any obvious fluid. So it's not clear how the fluid got all the way from the master cylinder through the booster and into the cabin. I'm going to start a new thread about that.
 
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