Removing the Brake Booster

[RRoller123]

Brake master is leaking like a puppy, out it comes. Replacing 37 year old booster at the same time out of convenience and caution.

So: Can someone outline, in simple sequences, the process of getting the Booster out of an FI car? Do I have to take off the Intake Manifold? Does it attach inside under the dash other than the pedal, just pulls straight off towards the front? etc? Any and all tips are appreciated before I tear into this thing.

Thanks.

Pete

[micbrody]

Do search on thread:

" Need to replace brake booster"

"http://www.fiatspider.com/f15/viewtopic ... it=Booster"

I detailed my experience. Manifold does not have to come off. Other important details ......read entire thread, especially if using $75 AR booster

[RRoller123]

Thanks!

Pete

[RRoller123]

That is a great thread and very helpful, I will make some inquiries before digging into this one.

Pete

[micbrody]

Message or call me if you need any help.......if home I can take a peek at car; probably some other stuff will come to mind

[RRoller123]

Thank you, that is most generous! It will take awhile, as I tend to move glacially on these project through the Winter. So far it has been a few days, and I have bought some brake fluid, ordered some parts, and raised the hood.

[spider2081]

Might want to listen to the TV Guy and "get er done" Spring weather could be here real soon. Just sayin

[RRoller123]

That's what I tell myself, then I get down and work on a cold unheated concrete garage floor and my old bones give me quite an argument about it.

[brackie1]

It was really ease on my '77. ONE unexpected thing was how far the plunger needs to stick out. It only needs to stick out about 3mm or so. The replacement one must be adjusted as they don't come with the right adjustment. I found out the hard way. If you have a good manual it will tell you. I just didn't read far enough.

[RRoller123]

Thanks, I will keep an eye on both of those issues. I made inquiries regarding the stud length and the push rod adjustment issues, and have been advised that there was a small portion of a production batch from maybe a year or so ago, and that the issues are resolved on all current stock.

Pete

[brackie1]

I had to take mine on and off 3 times before I figured out why the brake pedal was hard and would not stop. I mistakenly thought that the further out it was the better it would work. WRONG. When it is sticking out too far the master cylinder thinks the brakes are engaged when they are. That's why the plunger only sticks out but very little. They are adjustable. Mine came from the factory out too far.

[RRoller123]

Yep, thanks for the warning! There is a spec published somewhere for how far it is to protrude.

[brackie1]

My manual says 3mm. It's was a little hard to measure. Found a washer that was 3mm and used that.

[RRoller123]

Thanks, good tip!

[micbrody]

my manual said 1.0-1.9 mm.

I purchased the $75 booster from AR.
Before mounting it, I adjusted the push rod a low as it would go with included lock nut. It seemed slightly longer than it should be, but I still mounted it. Re-assembled everything (yes, the brake pedal spring took me an hour of contortion and tension to finally hook back up). Under no load, I had wife hit brake pedal off and on when I turned wheels. All seem great. I took for a ride. Seemed to great. Brake feel was much more responsive and firm. However, by end of quick ride, brake pedal was extremely firm. Also, the car would not passively roll backwards on incline of driveway!!!). I jacked up car, and front wheels were locked; and one of rear wheels dragged at lot on pads. I pulled up on brake pedal on inside of car. Even though it did not seem to move, the fronts became free. I theorized that pushrod needed to be shortened (I also, then recalled that when I went to bleed front brakes, the fluid did not easily come out when I first opened screws; only after some intermittent mityvac suction did it start to flow). I was able to easily disconnect only master cylinder and pull out push rod. I removed lock nut, and replace with a lock washer (and I applied some thread lock). I was able to reduce the length of pushrod by 2 mm. Re-assembled; everything works great!