Vlads Braking Thread Hijack

For non EFI mechanical discussion
Post Reply
MAGP
Posts: 665
Joined: Tue May 10, 2016 5:48 pm
cars: VC V8 sedan, VS V6 wagon, VT V8 Landcruiser.

Re: Vlads Braking Thread Hijack

Post by MAGP »

PBR are now owned by Bosch, they stop making new parts after 8 years.
Been through this process with my VC. I have VT fronts and am fitting VN Group A rears to bring the old girl nearer to the 21st century in the brake department. These fit within the original 15" Irmschers no problem.
I am debating whether or not to fit a VT booster and Master Cylinder to bring back some "feeling" to the pedal because even though the brakes passed rego last week they just don't feel like they are responding like they should.
User avatar
vlad01
Posts: 7780
Joined: Mon Oct 08, 2012 6:41 pm
cars: VP I S
VP I executive
VP II executive
VP II executive #2
VR II executive
Location: Kyneton, Vic

Re: Vlads Braking Thread Hijack

Post by vlad01 »

just the VH512 booster used in most VRs.

I found "feel" and response of the brakes heavily depend of rotors and pad choice. After going to slotted rotors I will never go back to non slotted ones. night and day difference and with good metallic pads they pull up like a modern car even with stock calipers, with good calipers you will probably get dizzy pulling up hard, they will work too good haha.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
User avatar
Gareth
Posts: 2505
Joined: Fri Mar 14, 2014 8:37 pm
Location: Bacchus Marsh, Vic

Re: Vlads Braking Thread Hijack

Post by Gareth »

I think MAPG's issue is more to running too small a master cylinder volume to caliper volume, the VT front calipers have a much bigger internal surface area that standard, require a 1 inch bore master..
According to chemistry, alcohol is a solution...
User avatar
VL400
Posts: 4991
Joined: Sun Mar 01, 2009 2:54 pm
cars: VL Calais and Toyota Landcruiser. Plus some toys :)
Location: Perth, WA
Contact:

Re: Vlads Braking Thread Hijack

Post by VL400 »

I had a custom 1" 1/16 master and VL booster with VT fronts. Pedal feel was ok but never great.

Changed to a VT master and VS booster, its a bolt in job on a VL other than the brake lines needing adapters or new flare ends, and now it stops on a dime with great feel. Def worth doing and booster+master was cheaper than just the custom master, and its all off the shelf parts again. Not that mush of my car is off the shelf :lol:
MAGP
Posts: 665
Joined: Tue May 10, 2016 5:48 pm
cars: VC V8 sedan, VS V6 wagon, VT V8 Landcruiser.

Re: Vlads Braking Thread Hijack

Post by MAGP »

Biggvl wrote:I think MAPG's issue is more to running too small a master cylinder volume to caliper volume, the VT front calipers have a much bigger internal surface area that standard, require a 1 inch bore master..
VTs have a stepped MC with 1 1/4-1 step in it. The VC come with a 1" anyway, I'd hate to think what it would be like with the smaller 15/16 MC. The VT brakes have huge pistons that need much more volume.
MAGP
Posts: 665
Joined: Tue May 10, 2016 5:48 pm
cars: VC V8 sedan, VS V6 wagon, VT V8 Landcruiser.

Re: Vlads Braking Thread Hijack

Post by MAGP »

VL400 wrote:I had a custom 1" 1/16 master and VL booster with VT fronts. Pedal feel was ok but never great.

Changed to a VT master and VS booster, its a bolt in job on a VL other than the brake lines needing adapters or new flare ends, and now it stops on a dime with great feel. Def worth doing and booster+master was cheaper than just the custom master, and its all off the shelf parts again. Not that mush of my car is off the shelf :lol:
VS booster with a VT MC requires a 1/4 adaptor plate between the booster and MC to take up the difference in rod length. I've done the research it's just a lack of funds atm to do any more with it. I need my 350 running so I am spending all my spare money on it. Cars are a terrible hobby :hmm:
Dylan
Posts: 3355
Joined: Mon Aug 02, 2010 6:35 pm
cars: VR Commodore V8

Re: Vlads Braking Thread Hijack

Post by Dylan »

MAGP wrote:
Biggvl wrote:I think MAPG's issue is more to running too small a master cylinder volume to caliper volume, the VT front calipers have a much bigger internal surface area that standard, require a 1 inch bore master..
VTs have a stepped MC with 1 1/4-1 step in it. The VC come with a 1" anyway, I'd hate to think what it would be like with the smaller 15/16 MC. The VT brakes have huge pistons that need much more volume.
Bigger stepped bore and bigger valving for the initial volume too.
User avatar
vlad01
Posts: 7780
Joined: Mon Oct 08, 2012 6:41 pm
cars: VP I S
VP I executive
VP II executive
VP II executive #2
VR II executive
Location: Kyneton, Vic

Re: Vlads Braking Thread Hijack

Post by vlad01 »

VL400 wrote:I had a custom 1" 1/16 master and VL booster with VT fronts. Pedal feel was ok but never great.

Changed to a VT master and VS booster, its a bolt in job on a VL other than the brake lines needing adapters or new flare ends, and now it stops on a dime with great feel. Def worth doing and booster+master was cheaper than just the custom master, and its all off the shelf parts again. Not that mush of my car is off the shelf :lol:
is the VS booster the same as the VR tandem? just wondering if a VT one would fit my VH512 booster which came on VP S and SS models that had "big brakes" and 1" MC

Also those booster were pretty much standard on VRs for 15/16" and 1" v6 and v8.

another thought, the res on the MC will need to be changed to the early type due to the angle of the lid?
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
MAGP
Posts: 665
Joined: Tue May 10, 2016 5:48 pm
cars: VC V8 sedan, VS V6 wagon, VT V8 Landcruiser.

Re: Vlads Braking Thread Hijack

Post by MAGP »

vlad01 wrote:is the VS booster the same as the VR tandem? just wondering if a VT one would fit my VH512 booster which came on VP S and SS models that had "big brakes" and 1" MC
From memory the VS had 2 different types of boosters. 1 is plastic and is physically smaller than the other, that one definitely requires an adaptor plate between the booster and a VT MC
User avatar
VL400
Posts: 4991
Joined: Sun Mar 01, 2009 2:54 pm
cars: VL Calais and Toyota Landcruiser. Plus some toys :)
Location: Perth, WA
Contact:

Re: Vlads Braking Thread Hijack

Post by VL400 »

I have the plastic VS V6 booster, with no spacer, and a VT master. There is an adjustment screw on the rod of the booster, use a plug instead and you get the ~6mm needed. Some later masters (think it was VZ, but not 100% sure as it was awhile ago I did the brake upgrade) were different so might need to be checked out.

A VT master needs the VS plastic reservoir (or a Falcon of the same era, they are the same) if you want the fluid to sit level on early cars.

A VT booster wont fit the firewall of pre VT, you would need to make up a bracket.
Post Reply