Firebird Master Cylinder Questions

[xanthias]

I have a couple of questions about this setup. Let me tell you what I think I know and please help educate me.

1. The hardware you want is a 1980(?) Pontiac firebird master cylinder
2. The purpose is to run 4-wheel disc (for example, when I get my 44/60 combo going with 4-wheel discs)
3. Do you also need a booster, or do you use the sammi booster?
4. Anyone seen a write-up on install or setup?
5. Do you need a proportioning valve?
6. Anything else about this setup I'm not even smart enough to ask about?

I think itsmejoe and a few others here are running this setup . . . so thanks for the help!

Search showed me these threads:

http://www.zukikrawlers.com/showthre...light=firebird
http://www.zukikrawlers.com/showpost...7&postcount=15
http://www.zukikrawlers.com/showthre...light=firebird

[Itsmejoe231]

1. The hardware you want is a 1980(?) Pontiac firebird master cylinder

You can get one at Autozone for $17.99. I was not in any hurry so I ordered mine online @ www.Autozone.com and had it shipped to my house. It is a 1980 Pontiac Firebird with 4 wheel disc brakes.

2. The purpose is to run 4-wheel disc (for example, when I get my 44/60 combo going with 4-wheel discs)

Yes, this will help you stop. The Sami MC dont push enough fluid to the calipars to make them stop very good. This Firbird MC is bigger and pushes more fluid and is made for 4 wheel disc vehicle.

3. Do you also need a booster, or do you use the sammi booster?

No, the Firbird MC bolts directly to the Samurai booster with a little bit of grinding on the bolt holes. I took a rotary file and my pencil grinder and outbored the Firebird MC holes about 1/8".

4. Anyone seen a write-up on install or setup?

You are looking at one now.

5. Do you need a proportioning valve?

I did not change anything on my Zuki brake system other than the MC and disc brakes on the toy axles.

6. Anything else about this setup I'm not even smart enough to ask about?

I used permatex gasket maker to seal it off on the brake booster.

Before installing, I took the Firebird MC to the Autoparts store and bought all my brake line fittings. It is easier to get what you need when you have the piece you are converting to in your hand. The firebird MC has 2 different sizes on the front and back connections and you have to adapt from those down to 3/16". I decided to cut my lines and covert them over to american so it would be easier later. I just cut the line and put on a 3/16" fitting and reflared the end of the line. I then bent new line to go to the MC.

The MC comes with a bench bleeding kit and makes things very easy to do. I installed the MC and then did the bench bleeding. Just seems easier and cleaner than doing it on a bench then having to intall it with brake fluid in it.

[xanthias]

Awesome information, Joe, as usual.

Is the metal forming the MC fairly compliant - could I do the bolt-hole modification by hand with a rat-tail file?

Also, FYI, you can get a booster to master cylinder gasket from the dealership for a couple of bucks. I've never been able to find one at the parts houses.

future search key words:
master cylinder booster firebird 1980 modification mod swap writeup how to how-to brakes pontiac samurai

[Itsmejoe231]

You probably could do it with a rat tail file if you had the patience. The metal seemed soft enough.

I used permatex gasket maker as a gasket. I am sure you probably could get a gasket if needed. I would get the Firbird gasket though.

[TX_ZUKI]

I did this same swap and I am amazed how well I can stop now. Thanks Joe!

[bigflex]

yes thanks for this write up i will be doing this in the near future and now ill know what im doing before i get started!

[Itsmejoe231]

Benji, what did you use to outboard the holes? I used a rotary file with a pencil grinder.

I am just giving people different options that dont have a pencil grinder.

[Vagabond]

Would this improve the performance of a stock Sammi brake setup?

[Itsmejoe231]

I think if you dont have enough pedal on a stock sami, then there is something else wrong.

It would be overkill because my stock MC would stop me with the toyota axles and rear disc setup. I didnt have much pedal left but it still would stop me. I went to the Firebird MC cause my stock MC was leaking.

So, why not up grade while I was at it?

[supazuk]

i found a rubber gasket in the heating section of my hard ware stock that fit real well. also there is a vacum port onthe botom of the firebird M/C that needs to be pluged some use RTV I however taped the hole put teflon tap on a set srew and blocked it off.
lastly you can use the early86-88 booster with no mdifications the later years you should extend the push rod

[TX_ZUKI]

Originally Posted by Itsmejoe231

Benji, what did you use to outboard the holes? I used a rotary file with a pencil grinder.

I am just giving people different options that dont have a pencil grinder.

die grinder.

[TheBanjoman]

Originally Posted by supazuk

i found a rubber gasket in the heating section of my hard ware stock that fit real well. also there is a vacum port onthe botom of the firebird M/C that needs to be pluged some use RTV I however taped the hole put teflon tap on a set srew and blocked it off.
lastly you can use the early86-88 booster with no mdifications the later years you should extend the push rod

Later years, extend the pushrod.. ?

How much extension??

I have the right size threaded bolt. about 2 inches longer. I Need to file the head to make it the same 'acorn shape' as the stock pushrod but wonder how much longer it should be. Bought it longer so I can cut it down but would like advice on how long it should be.

My pedal goes almost all the way to the floor. This is partly due to the crappy Cadillac Rear Calipers that I can't get properly adjusted (that is another story..) but I am also sure that with my '92 booster I need to extend the pushrod length.

I also didn't block off the vacuum port at the bottom of the MC. I need to do this too.

[xanthias]

Joe, what did you do about the Sammi brake fluid level sensor?

[Itsmejoe231]

Originally Posted by xanthias

Joe, what did you do about the Sammi brake fluid level sensor?

Oh, yea!! Just cut off the old lid and tie the two wires together and the brake light will go out. That is one option that you loose with this mod.

[Zee]

So Joe,how much room did you loose when you added the FB M/C and bent your own lines.
I have dual batteries,so i am concerned if i will have to relocate one to the rear.
Great write up by the way.
Z

[Itsmejoe231]

You could probably save some room by buying the 90* fittings so the tubing would not take up so much room.

How close is you second battery to the MC?

[Zee]

pretty close to the stock m/c and booster,a inch or two at the most.

[Itsmejoe231]

can you turn the battery to get more room?

[Zee]

I will have to get the Firechicken M/C and go from there.
I can go back to 1 battery if need be,just have to install the GM altenator so i can run all the accessories.
Z

[xanthias]

Okay, here's the specifics of the Autozone unit Joe referred to:

FENCO_REMAN Brake Master Cylinder for a 1980 Pontiac Firebird

Unit Price: $17.99
Core Value*: $8.00
Part No.: M1745
Weight: 7.8 lbs.
Warranty: LLT
Availability: Online: Ships within 2 business days
Store: Normally Stocked

http://www.autozone.com/servlet/UiBr...%7ENONE%7C%7EB

[Spinaldex]

Sorry to jump in to this late, but does this unit come with the fluid resoirvoir that I see in the pictures? The guy from Autozone that answered the phone said 'no', but I bet he's wrong and it's a once piece unit right?

[hillbilly]

Originally Posted by Spinaldex

Sorry to jump in to this late, but does this unit come with the fluid resoirvoir that I see in the pictures? The guy from Autozone that answered the phone said 'no', but I bet he's wrong and it's a once piece unit right?

The one I have is. One piece cast iron. I think autozone must suck out people brains when they hire them! If its not on the screen your screwed!

[Itsmejoe231]

yep comes with the resivour

[bigflex]

I guess I will have to do this once I put the yotas under silver!















oh an this is my 1,000th post I'm officially a POST HOE!
and I did it in just over 7 monthes

[TX_ZUKI]

Weak.






LOL congrats you hoe.