Moving the Brake Booster (Page 1/1)
michfiero1 APR 28, 07:46 PM
Hi All, I hope I am posting in the right section. Did some research but didn't find what I was looking for. I was wondering if anyone has ever moved the Booster lower in the car (towards the floor)...maybe 1-1/2"? I am trying to fix a clearance problem on my project.

Thanks in advance!
shemdogg APR 28, 08:50 PM
I tilted mine down a bit by putting washers under the top studs. My hood scoop was hitting the MC cap

shem
michfiero1 APR 29, 05:43 AM
Thanks Shem....I'll take a look tonite to see if that will work.
michfiero1 MAY 12, 01:15 PM
Success! Knowing the larger S10 booster mod works, I knew in theory it should work. So, subtracting the diameter of the Fiero booster from the S10 I knew I could lower it by 1 inch. So, made the measurements, drilled the holes...smacked the rail sheet metal (requirement for the S10) and it works. My initial concern was interference from the brake pedal bracket to the steering column universal but turned out there is sufficient clearance. So, if anybody asks....yes, you can moved the stock Fiero booster/master cylinder/pedal bracket 1" lower (towards the floor).

[This message has been edited by michfiero1 (edited 05-12-2019).]

Dennis LaGrua MAY 12, 02:54 PM

quote
Originally posted by michfiero1:

Success! Knowing the larger S10 booster mod works, I knew in theory it should work. So, subtracting the diameter of the Fiero booster from the S10 I knew I could lower it by 1 inch. So, made the measurements, drilled the holes...smacked the rail sheet metal (requirement for the S10) and it works. My initial concern was interference from the brake pedal bracket but turned out there is no clearance issue. So, if anybody asks....yes, you can moved the stock Fiero booster/master cylinder 1" lower (towards the floor).



Modifying the mounting geometry of the brake booster may not be a good idea. The standard mounting allows for the actuator rod to be perpendicular or inline with the brake pedal bracket. By lowering the booster the actuator rod is now at a sharp angle and may adversely affect braking action.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

michfiero1 MAY 12, 04:54 PM
Hi Dennis, very good points and they were definitely considered. I was able to move the entire assembly...booster and brake pedal bracket so there was no change in geometry. Thanks for the advice though!
theogre MAY 12, 06:36 PM

quote
Originally posted by Dennis LaGrua:
Modifying the mounting geometry of the brake booster may not be a good idea. The standard mounting allows for the actuator rod to be perpendicular or inline with the brake pedal bracket. By lowering the booster the actuator rod is now at a sharp angle and may adversely affect braking action.

that and booster has thick metal to mount where "firewall" and "tunnel" over steering column joins for a reason...
Hardware goes thru thick metal and must be a straight path to have all brake rod force to go directly thru the booster and MC.
Moving the booster down even a little will side load the booster causing binding and wear faster because booster is not made to handle the loads and booster can fail soon.
Sideways load may twist the whole center of booster and side load the MC too causing same problems to the MC making MC failure.
Odd loads after mod'ing may even flex the booster, combination valve and MC bodies themselves causing flex damage to metal brake lines. Hard lines will hate this and blow out w/o warning at any time.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

michfiero1 MAY 13, 05:34 AM
Ogre....apologies but I am not understanding. The entire assembly...MC/Booster and pedal bracket moved as a unit and the two lines from the MC were replumbed. There is no change in geometry and I made sure all 4 bolts are going through same metal thickness.