Author Topic: Brake Boster Input Please (Read 4199 times)

Hatchet · « **on:** June 09, 2011, 09:55:21 PM »

Hey all,

My next project is my brakes...

I'm looking at changin/replacing tha booster first up (to pretty things up and to maybe upgrade a little)

At tha moment im looking at something like this ebay item 320656008890

I have front disk, rear drum.
I dont really know anything much about brakes but will soon learn, lol.

any info on upgrades type thing would be good...

(last time drove a long distance to park up where I have been working on it, something snapped and seemed to cause a rear brake to sort of stay on, I am guessing it will be a spring inside)

Here is a pic of my current booster:

Also, is there a reason why these lines are coiled? (pic below)
Can I just use flexable line?

bonnevista · « **Reply #1 on:** June 09, 2011, 10:03:58 PM »

Whilst the brake lines are hard, the connection from your combination valve to the master cylinder isn't quite as rigid, so the brake lines are coiled to facilitate a little 'give'. If the brake lines were straight, they would still bend and flex, but would eventually become work hardened and crack.

SBC-68-FIREBIRD · « **Reply #2 on:** June 11, 2011, 01:59:54 PM »

I had a set of HQ brakes on the front of my 67 Parisienne with standard master cyinder & booster & it all worked fine.
With the rear brakes locking on check your body to diff flexible rubber hose. When they get old they can swell inside & when you put your foot on the brake the fluid pushes through the swollen hose & locks the brakes on but the fluid cannot return back through the hose as it is not under as much pressure. Just a thought.

Hatchet · « **Reply #3 on:** June 13, 2011, 06:40:30 PM »

Dose anyone know what my bore size would be..
I have no manual or such for my car...
Is there something online I can get this info from?

Thanx

bonnevista · « **Reply #4 on:** June 13, 2011, 07:43:52 PM »

Quote from: Hatchet link=topic=4437.msg27895#msg27895

Dose anyone know what my bore size would be..
Thanx

Well, first of all, I'd have to know what year you were born... Oh, you mean the car.:kick:

Anyway, as you have a disc/drum set up on your car, I'd assume that someone has fitted HQ Holden discs on the front and used a HQ master cylinder, just like SBC-68-FIREBIRD had on his Parisienne. This is the most common and cheapest disc brake conversion out there. Your car would have had drum brakes on the front originally.

The information for the specs on HQ Holden brakes would be readily available somewhere online.

The bore of the master cylinder is 1 inch.

Hatchet · « **Reply #5 on:** June 13, 2011, 10:17:54 PM »

Okies, yep 1967
Disk/Drum... will need to check what disk later... plan is booster/Master C., then rear drums.

1 Inch, kool

Thanx