Cobra brake booster question

Bdude93 · Dec 29, 2020

Hello,
New, First post!
I’m in process of a ground up restoration of a 90 LX (to cobra clone) front brakes are in. Now I know that the cobra brake booster is a bit of a pain to install. I believe 86 and earlier requires strut tower “massaging” and virtually all years require booster hole enlarging. My question is... is the process any easier with a completely empty engine bay? Without the engine or any other parts in the way? Cause my engine bay is freshly painted in eastwood ceramic chassis satin black and I’d hate to scratch it up getting this in...
Appreciate any input especially from those who have done it

General karthief · Dec 29, 2020

So, not to kick you in the nuts but, I think a cobra did not come with coil overs, tubular k member and lower arms.
Now I'm not criticising your work because it looks spectacular but a clone is the wrong term (in my opinion anyway) a clone is a copy, it's more a tribute, which in my opinion (again) is better than a clone because it gives the builder leeway for better handling and more comfort.
Oh, and more POWER!
Now get back to work.
And post more pics!

Cheapskate207 · Dec 29, 2020

I think the install will be much easier with the engine out.

nickyb · Dec 30, 2020

I'll be honest with you when I put cobra brake upgrade on my 93lx the booster was a pain but no banging or scatching,just elongated holes and wiggled it in.

Mustang5L5 · Dec 30, 2020

Yes, it can be done. It’s way easier with an empty bay, but I would painters tape everything in the area as you’ll be wiggling.

93 cobra booster will install the easiest. 94-95 booster will work as well but you’ll have to slot one of the mount holes. I trimmed mine down maybe 1/4”-3/8” on the inside two studs as well.

90sickfox · Dec 30, 2020

Word of advise. Cut an old antifreeze bottle open and cut a side of the bottle off to tape to the strut tower. That bottle plastic is almost indestructible and will keep you from scratching stuff. Could use it on areas of the firewall too...not directly behind where the studs will have to slide though. That area won't be seen anyways. When I install those cobra boosters I trim the studs down about 1/4 inch and smooth them around the edge just a little to keep from hanging up on stuff. Put a nut on the stud first. When you back it off it'll chase the threads.

That install is the worse job I've ever done on a mustang. Helps to have the drivers seat removed and a second set of hands with a flashlight to help line the studs up. It's all worth it in the end. You'll feel the difference.

Bdude93 · Dec 30, 2020

Solid advice! Thanks y’all

Bdude93 · Jan 9, 2021

Cut a half inch off the firewall studs and it slid right in! Was prepared for war and then smooth as silk...

nickyb · Jan 9, 2021

Nice , and no banging or scratching.

Bdude93 · Jan 9, 2021

nickyb said:
Nice , and no banging or scratching.

Nope. To be honest I may not have even needed to elongate the firewall holes. Went RIGHT in. Used to above tip of a piece of coolant jug plastic on shock tower to prevent potential scratching. Such a relief

Mustang5L5 · Jan 9, 2021

Yup. Despite what you may read, they can be installed without much fuss.

90sickfox · Jan 10, 2021

I was afraid to take that much off the studs...I only removed about 3/8ths. Good to know. Glad it all popped right in.

ThinBlue502 · Jan 10, 2021

I cut the studs on mine as well, slid right in.
Reference picture for V8 booster vs. Cobra booster.

5.0 Nostalgia · Jan 11, 2021

Great thread! Question: Can this project be done with the engine in the car AND without removing the master cylinder? I already have a 93 Cobra master cylinder and I was hoping to keep the lines connected to it.

Mustang5L5 · Jan 11, 2021

Yes. I've done it that way.

Siphon the brake fluid down a little bit in the MC, and tilt it forward to clear once you unbolt it.

As for getting the booster in place, I found removing my upper intake and just shifting it over to the pass side gave me enough room. I've heard of some people removing a valve cover as well. Mine were stock VC's, but if you have some tall VC's it might be an issue.

And like mentioned, I did trim the studs down a little.

It will go, just need to pick a day where you can be patient with it.

5.0 Nostalgia · Jan 11, 2021

Thanks for the help. I was thinking I would need to take off my upper intake and unplug all the vacuum lines, etc. (luckily I don't have A/C!). Do you mean that you trimmed the studs on the interior side or the studs for the master cylinder (or both)? Also, do you know which hole(s) need to be opened up on the firewall to slide this in? I assume it will be hard to determine that by test fitting!

Thank you again. I hope I am not hijacking the thread.

Habu135 · Jan 11, 2021

5.0 Nostalgia said:
Thanks for the help. I was thinking I would need to take off my upper intake and unplug all the vacuum lines, etc. (luckily I don't have A/C!). Do you mean that you trimmed the studs on the interior side or the studs for the master cylinder (or both)? Also, do you know which hole(s) need to be opened up on the firewall to slide this in? I assume it will be hard to determine that by test fitting!

Thank you again. I hope I am not hijacking the thread.

I just did this mod. Removed my upper intake, windshield wiper motor and pulled the MC forward. Cut down the two passenger side bolts and enlarged the passenger side holes a bit. I also disconnected the clutch cable. Went right in.

Bdude93 · Jan 11, 2021

5.0 Nostalgia said:
Thanks for the help. I was thinking I would need to take off my upper intake and unplug all the vacuum lines, etc. (luckily I don't have A/C!). Do you mean that you trimmed the studs on the interior side or the studs for the master cylinder (or both)? Also, do you know which hole(s) need to be opened up on the firewall to slide this in? I assume it will be hard to determine that by test fitting!

Thank you again. I hope I am not hijacking the thread.

You trim down the 4 studs going into the firewall. I personally just enlarged all 4 holes a bit, but after trimming studs down, I wonder if it was even necessary. But doing both makes install effortless

5.0 Nostalgia · Jan 11, 2021

Thanks everyone. I installed the older Baer PBR front calipers (basically the same as the Cobra calipers but the spindles are set up for a 4 lug 12" rotor) and 93 Cobra master cylinder. I thought I could get away with leaving the booster but the pedal effort AND braking is terrible. Was going to install the booster first then finish the project with a 4 lug rear disc conversion.

Mstng93SSP · Jan 12, 2021

My personal opinion, the cobra booster is more important that the cobra master cylinder. Cobra master with a stock fox booster and the pedal effort is bordering unbearable. However, a stock MC with a cobra booster and it isn't bad. I am NOT saying you shouldn't do both, but if you had to do one first, before the other I would always do the booster first. I had a coupe about 8 years ago that had a 5 lug sn brake setup with a cobra mc and stock booster. Had a panic stop situation on the freeway and it was a very scary moment, both feet on the brake pedal as hard as I could and it just would not stop.

Cobra brake booster question

Bdude93

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General karthief

wonder how much it would cost to ship you a pair

Cheapskate207

The left one hangs a little lower

nickyb

I gotta say i never painted my nuts, Never Ever

Mustang5L5

That is…until I whipped out my Bissell

90sickfox

Wasn't a pretty sight...and I've got big hands

Bdude93

Member

Bdude93

Member

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nickyb

I gotta say i never painted my nuts, Never Ever

Bdude93

Member

Mustang5L5

That is…until I whipped out my Bissell

90sickfox

Wasn't a pretty sight...and I've got big hands

ThinBlue502

5.0 Nostalgia

Mustang5L5

That is…until I whipped out my Bissell

5.0 Nostalgia

Habu135

Bdude93

Member

5.0 Nostalgia

Mstng93SSP

You have a nice rear end there Dave.

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Cobra brake booster question

Member

Attachments

wonder how much it would cost to ship you a pair

The left one hangs a little lower

I gotta say i never painted my nuts, Never Ever

That is…until I whipped out my Bissell

Wasn't a pretty sight...and I've got big hands

Member

Member

Attachments

I gotta say i never painted my nuts, Never Ever

Member

That is…until I whipped out my Bissell

Wasn't a pretty sight...and I've got big hands

That is…until I whipped out my Bissell

Member

You have a nice rear end there Dave.

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