A bad bomb will give you a pedal hard as a rock upon aggressive or panic braking. The pedal will not move and you will need to release and reapply to get normal braking.



BRAKE BOMB REPLACEMENT


1. Get in car and with engine off, pump brake pedal twenty times (relieves the pressure).

2. Loosen lug nuts on drivers side wheel. Open hood, and take lid off of PS reservoir.

3. Jack up and support (jack stands are good) the front end, or a least the driver’s side.

4. Remove the wheel/tire assembly.

5. Remove the two bolts in left front wheel housing that hold the alternator intake air duct and
Remove the duct (this is a horizontal panel of fiberglass and is just below the bomb).

6. Now you can see the bomb and the two (10 MM or 12 MM) bolts (top and bottom) that support the
Bomb. You can also see the compression nut, but can’t get a wrench (19 MM on mine) on it.

7. OK, here is my non professional method of removal:
a. Using a dremel or any cutting tool, cut a window in the splash panel in front of the tire you
Removed in the area that will expose the compression nut on the bomb.
a. Using your open end wrench unscrew (at leas break free) the compression nut and then you
can hand loosen and remove. Paper towels or rags beneath the bomb will catch any residual
fluid that may leak out, do not expect a lot of fluid.
b. Now remove the two support bolts and the bomb drops out.

8. Make sure you have a rubber “O” ring gasket to go over the threaded portion of the bomb (my
Bomb did not come with one and my old bomb had none (dealer item and about $3.00).

9. Lubricate “O” ring with Pentosin, place over threaded neck of bomb, place bomb in position and
Lightly (finger tighten) the two support bolts (just to hold bomb in place).

10. Thread, carefully the compression nut onto the bomb and tighten (it takes only about 30 lb/ft
Of torque).

11. Tighten support bolts, top off PS accumulator, start engine, pump up brakes and check PS
Accumulator one more time, checks for leaks (you shouldn’t have any). Replace panels, replace
Wheel and tire assembly, lower vehicle to ground, test drive.

13. Check PS accumulator one more time, and top off if necessary.

14. I cut a piece of black plastic slightly larger than the window I cut out and RTV’d it over the hole
I cut so I am ready for the next time. I bought my BRAKE ACCUMULATOR from
Bimmerparts.com, but check for prices, (bombs for735’s are less expensive than 750’s).

Written by: Richard “The Bear” LaBarre