Rednroll

Ok, so I'm in the middle of doing a Mopar big brake kit install, currently removing the stock parts and the last part I need to remove is the stock brake booster.

While the previous step of removing the brake pedal retaining clip was a PIA, the final step of removing the 4 nuts which hold the brake booster has me stumped.

Somehow/Someway from the factory install, the booster is currently mounted where the booster mounting bolts are not centered in the mounting holes and the nuts are in a position that the firewall is preventing me from being able to get a socket on any of the nuts, and the nut is below the sheet metal of the firewall so I can't get an open end wrench on them as well, even if I could reach them with an open end wrench which would be very difficult.

Anyone have any tips/suggestions on how to go about getting these brake booster nuts off?

Here's what the current situation looks like. Notice how there is no clearance on the top sides of the nuts from the sheet metal of the firewall.

Mark Doiron

I see the problem with clearance you have--but hold that thought. I want to ensure that you know the nuts are captive hardware. So, they aren't going to back off. You'll have to loosen one a little until it tightens up in the captive housing, then loosen all the others, and keep working your way around. So, you may not have so much of a clearance problem as a problem with bumping up against the captive housing.

This image from my FB page may help ...

EDIT: Oops, let the text truncate in the image below. Here it is: In order to rotate the clutch master cylinder you'll have to make clearance for the connection to the brake fluid reservoir to rotate around--it bumps into the power brake booster. So, remove these four nuts behind the firewall. The nuts are captive--they will stay in place up there once the brake booster is loose. Because they are captive, you'll have to loosen each one a little bit, then move on to another one, keeping all within a few threads of each other on the stud. If one starts to get tight as you're unscrewing it, move on to another one and return to that one when you get the other ones about even with it. From under the hood, pull the booster forward to clear the holes for the studs, then push it to the side--only about 1/2" clearance is needed. Be careful to not put too much pressure on other hydraulic lines.

Rednroll

Hi Mark,
Thanks for the additional info that's very helpful, I likely would have gotten further frustrated once I reached that step of actually being able to loosen the nuts.

The big question is figuring out how I'm going to be able to get to that point of actually being able to loosen them.

Right now, what I'm thinking about is putting a 13mm deep well socket on the bench grinder and making my own custom socket for this task. I grind down enough of the socket opening on one side to provide clearance away from the sheet metal, and hope I still have enough socket bite to be able to turn the nut. Now we know what cheap taiwan/chinese made not so hardened metal tools are good for.....customizing.

I'm not much of a wrench guy and this is my 1st time removing a brake booster, so I'm thinking someone else probably has a better/smarter suggestion for this problem.

No pun intended, but I really wish my nuts looked like yours and were nice and centered. LOL!!!

Mark Doiron

That is probably your best option. I'm trying to figure out how this got down the assembly line so far off! Regardless, good luck.

Rednroll

I was wondering how in the assembly process that the nuts could have even gotten tightened down to where they're currently at. I worked in a Dodge truck assembly plant part-time in the past when I was going to college and essentially they used air-compressor socket wrenches tuned to a particular torque to fasten things like this down. So if I'm having difficulty getting a socket onto the nut, they should have had the same problem when tightening down those nuts and the nut should have stopped being tightened once the edge of the socket hit the sheet metal. I dunno.

If I had enough clearance room from under the hood, I might even consider taking a sledge hammer and pounding the heck out of the brake booster to see if I can some how get it to slide down into position. I already have a replacement. Unfortunately a bunch of wire harnesses, ABS, and brake lines are in the nearby vacinity and I'ld be afraid something else might get damaged if the metal decided to bend instead of the booster sliding down.

Invest2m4

The blue colored plate doesn't come out? Looks like it would.

Rednroll

Unfortunately no. You can see in Mark's picture since that has the surrounding rubber mat removed, it's part of the firewall sheet metal that is painted. It's not a separate a plate.

Rednroll

Thanks for the assistance. Flywrangler put me on the right path in this other discussion I was having when I originally ran into this problem.

https://www.jk-forum.com/forums/modi...-326059/page3/

I should have followed the provided instructions....or at least tried to understand them a little more.

It seems the brake booster can be removed 1 of 2 ways. There's a mounting plate inside the engine compartment that the brake booster mounts. Those are the 4 nuts shown in the pic above. The mounting plate attaches to the firewall by 4 nuts from inside the engine compartment. So if you unfasten the 4 nuts inside the engine compartment, then alls you need to do is push the booster away from the firewall and it comes off with the mounting plate attached. If you remove the 4 inner nuts like I was trying to do, then it leaves the mounting plate attached and you can then remove the brake booster that way as well. That's the reason, some way my inside nuts where off center, because those nuts don't have to be fastened to the plate from inside the cabin.

Mark Doiron

Awesome--good to know!