Squeaky brake system following emergency stop

[paulyg]

I have this exact same problem. Prompted a pedal box rebuild (well worth it). However the issue is that the pedal box extension and booster bracket are sliding relative to each other. It’s simply not possible to get the brake pivot bolt tight enough to prevent the motion without causing the pedal to bind. Anyone worked through this successfully? 

[Son of Marty]

Are you sure you have number 13 and the washers in the correct order, the tube 13 should prevent the pinching your having.

 

[paulyg]

Washers are supposed to go outside the pedal box bracket tabs, correct?

 

I am using the IE booster pivot kit and couldn’t get the spacer washers installed. I guess I have myself to blame for this. 

[Dudeland]

21 hours ago, paulyg said:

 

I am using the IE booster pivot kit and couldn’t get the spacer washers installed. I guess I have myself to blame for this. 

 

I have one and for the life of me, I couldn't get it installed.  I am waiting until I pull the engine.  

 

 

[tzei]

Would loosening p/box bolts, booster bracket etc provide enough ”room” to get that pivot bolt tight & pivot operational and then thighen all the rest back?

[paulyg]

Not really, the booster pivot bolt needs to clamp the pedal box extension and booster together. A better design would have been to use a shear pin or two, but BMW cheaped out here. The stock spacer/bushing stack would work well off the factory line, but as everyone has found, it wears out and you run into pedal slop problems as well as the loss of preload on that bolt. The IE solution seems to be pretty good on paper, but is impossible to install. 

 

I may try to comb through sealed bearing catalogs to find substitutes for the sealed bearings in the IE kit with inner races with integral spacers. Getting the spacers installed is the quandary that elevates the kit install from a simple drop in to "you're better off pulling the entire brake system" territory. 

[paulyg]

Minor update, I managed to monkey the inboard spacer in but I'm still working on getting the other spacer into the stack. I have not pulled the booster bracket. 

 

IE really should put in bold, all caps, on the product page, that IN ORDER TO INSTALL THIS YOU MUST REMOVE THE BOOSTER BRACKET. Had I known what an absolute PITA this kit is to install, I would have just let sleeping dogs lie. 

 

Of course, IE can't be faulted for the absolute disaster that is the original BMW engineering of this particular area, which I will call the brakemuda triangle. To my eye, the original design puts a bushing just about everywhere except where the actual wear would occur. My feedback in a hypothetical design review which should have occurred in the summer of 1964 (but evidently didn't, or was held at the bottom of a bottle of schnapps) would have been "If the booster bracket must be braced by an extension of the pedal box, why not constrain the two parts using shear pins, instead of inappropriately recruiting the booster pivot bolt?"