HELP PLEASE: VT Brake Conversion Issues...

[g00gz]

I have ripped off my old brake and am mid way through a brake conversion and well, i'm stuck....

I've gone with VT calipers, VN V8 rotors (so I don't need hub adaptors), and obviously the VT (well they gave me VX, which is supposidly the same) brake booster and master cylinder, and thats where my problem lies, its with the master cylinder...

You see when you look at where the brake lines go into the Master cylinder, they don't line up with the original vn master cylinder ones, infact they arn't even close, so what am i to do???!!!! Any help would be greatly appreciated!

[vpbt1ss]

mate just run a 1" master cyl no need to change to a vt/vx booster/master my vp v8 had the 1" master on it pedal is fine

[AirStrike]

I have ripped off my old brake and am mid way through a brake conversion and well, i'm stuck....

I've gone with VT calipers, VN V8 rotors (so I don't need hub adaptors), and obviously the VT (well they gave me VX, which is supposidly the same) brake booster and master cylinder, and thats where my problem lies, its with the master cylinder...

You see when you look at where the brake lines go into the Master cylinder, they don't line up with the original vn master cylinder ones, infact they arn't even close, so what am i to do???!!!! Any help would be greatly appreciated!

HAHA! No chance champ. There is quite alot of modification required to fit the VT-VZ booster and master. The booster mount holes wont line up with the fire wall bracket, the rod length is all wrong, etc.
AirStrike

[g00gz]

mate just run a 1" master cyl no need to change to a vt/vx booster/master my vp v8 had the 1" master on it pedal is fine

thanks for the reply guys. OK so I can run the standard vn booster with this 1" master cylinder? If so, is this master sylinder off another model commodore (vn v8 i assume), if not will it line straight up with the booster?

Thanks again...

[g00gz]

I've been thinking about this... if i cant use a vt master & booster then what is the difference between VN V8 brakes and Vt Brakes??? They are both 290mm arn't they?... meaning the master cylinders & boosters would have to be pretty much equivelant in output wouldn't they? So the only real defference would be in the calipers, being that the vt ones are twin spot? Am I correct in all my thinking?...This is all gettin to me!!!!

[AirStrike]

I've been thinking about this... if i cant use a vt master & booster then what is the difference between VN V8 brakes and Vt Brakes??? They are both 290mm arn't they?... meaning the master cylinders & boosters would have to be pretty much equivelant in output wouldn't they? So the only real defference would be in the calipers, being that the vt ones are twin spot? Am I correct in all my thinking?...This is all gettin to me!!!!

The VN V8 brakes use a finned single piston caliper with a ventilated 289mm rotor. The VT however is a twin piston caliper with a ventilated 296mm rotor.
The master cylinders and boosters are quite different.
The VN booster is a double diaphram unit with a ratio of 4:1, while the VT unit is 4.25:1. The VT master cylinder is know as a fast fill unit having a 1.25" primary versus the 1" of the VN unit. This helps with the spongy pedal feel with the larger caliper. Hope this helps.
AirStrike

[vpbt1ss]

my last vl turbo i built i used the 1" vp master witht the vt calipers pedal feel was real good and was real good stoppers and my car really needed big brakes as i has over 340hp at the wheels never had a problem stopping

[markovr]

The vt setup is a step ahead of the stocko booster/master.Booster assistance is greater and the cylinder is different in size.
The front lines go to the rear and the rear to the front of the cylinder.
Vps use the same flares as the vt but some vns used different flares so you might need adapters after that the lines are carefully bent to line up with the place in the new master The pushrod from the booster acts directly on the front brake piston in the master .
You need to adapt the bracket to fit your cars stud holes and weldup and redrill the pushrod hole for the pedal pin so the brake pedal ends back where it used to be.
I speak from experience I have it on my car done all by myself ...not read from someone elses posts.
Here is a picture of what mine looks like after I had moved the hoses to suit http://forums.justcommodores.com.au/...2&d=1104659672
Pict is the booster bracket modified and a few dimensions from jimbo webpage

[AirStrike]

The vt setup is a step ahead of the stocko booster/master.Booster assistance is greater and the cylinder is different in size.
The front lines go to the rear and the rear to the front of the cylinder.
Vps use the same flares as the vt but some vns used different flares so you might need adapters after that the lines are carefully bent to line up with the place in the new master The pushrod from the booster acts directly on the front brake piston in the master .
You need to adapt the bracket to fit your cars stud holes and weldup and redrill the pushrod hole for the pedal pin so the brake pedal ends back where it used to be.
I speak from experience I have it on my car done all by myself ...not read from someone elses posts.
Here is a picture of what mine looks like after I had moved the hoses to suit http://forums.justcommodores.com.au/...2&d=1104659672
Pict is the booster bracket modified

Been meaning to PM ya Mark..............wouldnt have a spare bracket lying around I could buy off ya This VN is gonna need the VT setup me thinks....
AirStrike

[markovr]

YEP... sure have and I can do a complete vt booster moded and tested to fit a vn/p/r/s for 160 or just the bracket for 60 (fair bit of work in the bracket) + POST of course

[Blown V6 Hatch]

I have ripped off my old brake and am mid way through a brake conversion and well, i'm stuck....

I've gone with VT calipers, VN V8 rotors (so I don't need hub adaptors), and obviously the VT (well they gave me VX, which is supposidly the same) brake booster and master cylinder, and thats where my problem lies, its with the master cylinder...

You see when you look at where the brake lines go into the Master cylinder, they don't line up with the original vn master cylinder ones, infact they arn't even close, so what am i to do???!!!! Any help would be greatly appreciated!

Vt calipers on Vn V8 rotors, noooooooooooo not the right way of doing it at all! Vt rotors are thicker than vn v8 rotors and as the pads start to wear the the pistons in the calipers have to travel further with the vn rotors than they would with the Vt rotors and the pistons can fall out of the calipers. End result, NO BRAKES!

[Blown V6 Hatch]

Also i would highly recommend doing the VT master & booster conversion. I have the VT brakes with the VT booster & master conversion on my calais and the brakes are awesome with a really good pedal feel.

[markovr]

Yep I can vouch for that ...less pedal travel more assistance and the pads seem to bite more with less effort.
Also I always found that with the old booster with the engine just turned off and your foot on the pedal the power booster assistance would bleed off and push back against your foot after about 10 sec....I had 2 cars with the old setup so it isnt a faulty unit.
The Vt booster doesnt do that...

[g00gz]

Vt calipers on Vn V8 rotors, noooooooooooo not the right way of doing it at all! Vt rotors are thicker than vn v8 rotors and as the pads start to wear the the pistons in the calipers have to travel further with the vn rotors than they would with the Vt rotors and the pistons can fall out of the calipers. End result, NO BRAKES!

according to the DBA Catalogue, the VN V8 and Vp Series 1 V8 have the same thickness rotor as the VT. It was only the VP Series 2 V8 onwards that had the thicker rotors.

Anyhow it is all done now and it all works a treat, so thanks everyone for your advice

[markovr]

Heres a picture of my vp with the vt master/booster setup that I installed today in about 2 hrs. Its a bolt in with all you have to do that is a bit finicky is bend your brake lines to suit the new cylinder.
Results are instant and all I had to do is bleed it at the lines and it was in and going..didnt even waste much fluid
http://forums.justcommodores.com.au/...1&d=1150621024

[freakme]

What do u guys recommend regarding a brake upgrade for a VS Exec V8? Did the entire VT model come with twin-spot calipers? Are they finned as well?

Just sussing out what brake package would be a suitable upgrade for the VS model and cost effective to contemplate.

Assistance appreciated.

Cheers Freakme