Vt booster m/c in Vr V8 with ABS

[VrWagz1]

Vt Booster and Master in your V8 VR with ABS

Ok this is for noobs like myself trying to find some info on how hard it is putting in the vt booster and m/c into the vr. So like me you've gone out and put the vt rotors and calipers on your vr and despite your best efforts you cant agree that the pedal is ok. Its way too long and dosn't do your new brakes any justice and are performing very poorly. So I went and got myself a vt booster and master cylinder, and lucky for me I got it off another person who had already made the modified mounting bracket up , If you need to know how to make the adaptor bracket see down below "post #18". In the mean time, as a word description, you need to bend in the corners of the old bracket till they touch, then weld a peice of flat plate on the end of it, and re-drill that plate for the 4 booster bolts. You will also need to re-drill the pushrod brake pedal hole back a bit(110-113mm from the base of the bracket i think from memory but CHECK FIRST by installing and marking it.)
The only thing not shown here is a heavy duty strut tower bracket, which is not nessacary but it recommend it. I cut one out of a peice of RHS cause i could utilise the edges as a pre-bent 90 degree angle. All i needed to do was trace the bracket shape on the rhs and used the grinder to cut it out.

Ok so this for those of you who are a little unsure about changing the Booster and M/C out and bending up the brake lines and worrying about the abs, like myself here is a simple guide with a few pics. Its not particularly hard anywayz, just takes a few hours of ur time.
You will need a 3/8 socket set, an assortment of metric spanners and maybe a 3/8 spanner, imperial Allen key (for rocker cover bolts), A bottle or 2 of break fluid. Screwdriver pliers ect..

Removal of the old
1. I put the front end of the car up on ramps, because about 2/3rds of the time it was a better working height. Then start pulling off the covers off under the the drivers compartment. Ok were ready to start.
2. Crack the nuts of the brake lines on the master cylinder, just to be sure they will undo. I found the front brake line (the bigger one 13mm) cracked ok, but the rear (10mm) was seized and I simply rounded the nut. So I bashed on a 3/8 spanner and cracked it with that. Now leave them there finger tight. Pull off the brake fail light wiring plug from the underside of the m/c and crack the bolt on the strut tower bracket.
3. Inside under the drivers compartment you will see the pushrod attached to the brake pedal and the nuts holding the booster to the fire wall (12mm). Crack the nuts on the fire wall and slide the clip off the brake pedal holding the pushrod on.

4. You now need to get the vacuum hose and plastic fitting out of the booster. It took me about half hour of stuffing about to workout how to get it out because I didn’t want to break it. Turns out it’s just a case of pull harder and on a bit of an angle.

5. Ok everything should be loose now and ready to pull out. Stuff heaps of newspaper or rag under the master cylinder to catch any dripping brake fluid(As it will strip your paint). You can now take all the nuts, brackets, brake line off in one hit and just pull it out.

6. Tape over the brake lines and vacuum hose to stop any dirt getting in.

In with the new
1. It is best now to bench bleed your new master cylinder so you don’t put any air through the abs unit. Plug all the holes with some bungs
(But not attached to booster while doing this).
Now leave one of the bungs loose and push in the back of the cylinder fairly hard to force the air out that bung, then close it shut and let the cylinder out and it will draw in fluid from the reservoir. Repeat around the other 2 bungs. *Edit. Alternitavly after you have it installed and are ready to hook in the brake lines have someone pump the brake pedal a few times while you hold your fingers over the holes on the master cylinder and let the air out till fliud comes out the holes. Then do your best to simply plug in the brake line before you lose too much fluid.

2. I found that because the VT booster is slightly bigger, it just didn’t slide back in (doh), it jams between the rocker cover and the strut tower. So I had to take the rocker cover off. Easy to do, there are 2 Allen head bolts in the top and 4 around the base lip and it just lifts out. But if you know the right places to jack the engine to tilt it slightly to one side, then that may be easier, as I spent about an hour trying to get the back bolt back in the rocker cover. Was just a real pain to get to once the bigger booster was in the way. (EDIT: from experiance now, it is definatly recommended to jack the engine over just a smidge, so much less stuffin about and no worrying your rocker gasket might start leaking)

3. The booster fits in now and you can make sure the pushrod finished up on the right side of the brake pedal and put the nuts back on the fire wall studs to hold it all steady and put the rocker cover back on.

4. Ok we need to hook the brake lines back in. Being a vr there is no adaptors needed. Simply just need to bend the brake lines around to suit the new m/c configuration. The lines bend very easily by hand, just be carful and don’t kink them. The front brake line pretty much lines up and bolts straight back in. I had to only bend mine slightly as it was in the way of the brake fail wiring plug. The rear brake line is a bit of a problem though, as it was miles away from being in the right spot as it now goes into the side on the m/c and not in the bottom. The rear has two, 90 degree bends where it goes across and back up to the abs unit. Simply do your best to straighten these out a bit to get a bit of length on it, then you can put a nice radius on it so it will bend around into its new home.

5. Almost over. Simply install your new strut tower bracket and bolt it all up. Put your clip back onto the pedal to hold the pushrod on. Check the little brake light and cruise cancel switch above, where the brake pedals bump stop is(i had to adjust mine slightly as the cruise control would disengadge when i hit a bump and vibrate the pedal + the brake lights were on almost instantly instead of waiting for a few mm of pedal travel first). Hook the return spring back onto the pedal if you took it off. Hook up the brake fail wiring and put the vacuum line back into the booster and your ready to bleed it all up

6. You should all know how to do a full bleed up your brakes so I’m not going into that, if your not sure on that, then get someone who knows what they are doing to help you, its very important to get all the air out of the lines, there is probably a how to somwhere here anywayz. *Edit. Just a note, dont go nuts on the brake pedal straight up when you start to bleed as the master cylinder will have some air in it still. So just some short gentle pumps to let the air out and the fluid in(note how the air bubbles up into the reservoir as you let the pedal out and it draws the fluid into the master again to refill it). Also(as a side note), long stokes on the new master(only if its second hand) can be bad as is will stroke the master's piston over its original travel working range and if it happens to have worn a little lip at the end of its working range you can somtimes damage the seals on the piston when pushing the piston over the lip. This can cause it to bypass and you will have fluid leaking out of the back of the master and running down the face of the booster. Worst case with my old one was the fluid dripped down onto the rail, stripped the paint and it started to rust costing me a small fortune to fix.
And the result is very pleasing. For the first time it is very easy to pull up the old wagon at the bottom of a hill and the calipers and rotors now feel like they are actually working properly and the pedal is nice and high again, I can actually pull up alot later than i used with confidence. Ok that’s it, please feel free to leave any constructive criticism and things you would have done differently, or little tips and hints.

[VrWagz1]

Hope this wasnt to long winded

[Wagon_Wheel]

Great write up mate, will be tackling this when i get around to it.
I already did the calipers and rotors and that, so i know what you mean about the pedal!
Good rep left

[VrWagz1]

Cheers wagon_wheel

[VrWagz1]

Just an update to this, As there was some questions raised before about the legalites of the vt brake upgrade. NSW, I have had it inspected by an engineer and he had no dramas with it. I still need to get it blue slipped yet, but i dont think it will be a problem.
I also had a mate who wanted to do this too. So i had a go at making the bracket off jimbos website out of my old vr bracket and it was a peice of cake. I cut the heavy duty strut tower bracket out of a peices of gal RHS. Welded it all up and only had to make some minor adjustments and was all good. Didnt even need to take the rocker cover off. For some reason he had an extra poofteenth of a gap there and the booster just squashed through

[markovr]

Yep good write up...I've done a few and I actually use a few gigs to make all the drilling and bending a no brainer(suits me)....jimbos redrilling dimension for pedal pin hole in pushrod is out by a few mill I think its 111 and I found by measuring the stock vr one it was 113 (this affects pedal height at rest) and the use of a vs resevoir in the vt master is probably recommended but you dont have to...its just the top of it will be level then.You will have to drill and tap a small metric thread in the webing under the resevoir on the master to mount it Ihave found that a au falcon resevoir will fit(shock horror) perfectly without having to tap any new hole if you can get one.Also I use the plastic filter/ insulator from the earlier model booster and cut the square face off it the booster end and mount over the pushrod before I bolt the bracket to the booster so there is a effective air tight seal from the engine compartment to inside the car when the booster is mounted to the firewall...this stops any unwanted noise ,drafts etc

[VrWagz1]

Thats a good idea mark for the firewall. As for the final step for legalities for insurance ect.., i have had the car blue slipped now and have had it rubber stamped by the rta. So its all completely legal now with no worries.
It all came up to a grand total of $600. That included, vt rotors calipers, vt Booster and master, adaptor braided lines, hub spacer rings, engineers certificate ($170 ), blue slip, brake fluid ect. Probably would have saved about $100 if id made my own adaptor bracket for the vt booster to fit in. So if you make your own bracket you could do the whole upgrade for about $500 fully engineered.

[Jimbo]

Yep good write up...I've done a few and I actually use a few gigs to make all the drilling and bending a no brainer(suits me)....jimbos redrilling dimension for pedal pin hole in pushrod is out by a few mill I think its 111 and I found by measuring the stock vr one it was 113 (this affects pedal height at rest) and the use of a vs resevoir in the vt master is probably recommended but you dont have to...its just the top of it will be level then.You will have to drill and tap a small metric thread in the webing under the resevoir on the master to mount it Also I use the plastic filter/ insulator from the earlier model booster and cut the square face off it the booster end and mount over the pushrod before I bolt the bracket to the booster so there is a effective air tight seal from the engine compartment to inside the car when the booster is mounted to the firewall...this stops any unwanted noise ,drafts etc

Yup,.. pedal pin hole difference was out a small amount,.. mine ended up little loose from memory I think? Can't recall now it was so long ago. The resovoir change is a good change, but not essential.

The strut tower bracket is a good addition.

Good to see the info has been useful to so many.

I'll get back to the project one day, as its pretty much been idle for quite a while now.

Jim.....

[markovr]

Another thing I remember is a small 1/4 inch spacer (you can see it between the front bolt and master cylinder in this picture )between front of cylinder and strut bracket... gives you more clearance and makes the pain of fitting a spanner between the strut tower to do up the nuts and the cylinder a heap easier.

[undar8ed1]

This write up is great, just finished this job and those little hints cuts out any time loss, great write up mate can`t leave any rep but if I could I would, also I did not replace the strut mount is that bad, as fords don`t use em with no probs.
P.S thanks to markovr for the gear to do this.

[VrWagz1]

Cheers mate. I did it to stop the firewall flex. Grab a mate to push on the brake pedal and whatch the booster. You will be surprised how far it moves forward (firewall flexing). The heavy duty strut tower bracket reduces this, but its up to you if thats a problem or not.

[undar8ed1]

Ok, will look into that.

[chrisdoesitbetter]

nice work! hows it perform?? and is it worth our time and money

[VrWagz1]

I wouldnt be without it with the twin piston vt calipers, but i have also heard a few people doing it with just the standard brake setup and they recon it was a great little upgrade. I think 88greenVN was one who has done it to his standard setup if you maybe wanna pm him to ask him how it went.

[Fonzie]

jimbos redrilling dimension for pedal pin hole in pushrod is out by a few mill I think its 111 and I found by measuring the stock vr one it was 113 (this affects pedal height at rest)

I'm aware this is a bit of a thread dig... But It's the only one I could find with relevant information. "Jimbo" was referenced earlier in the thread with a link to a VNAERO website or something along those lines, but the link was dead.

My question is; Will I need to drill a hole in the pushrod of the VT booster to match up with the VS pedal?

And my VS doesn't have ABS, does anyone know if these lines will still reach the appropriate holes in the new booster?

Cheers, Fonzie.

[Jimbo]

Hey Fonz,

I pulled the site after bigpond changed what they offered. Haven't really thought of trying to get it back,.. most people have copied and come up with similar solutions now. Jeez its been a few years now LOL.

Have never owned a VS or worked on one,.. but will try answer; perhaps someone else can chime in.

You'd need to redrill the rod to match your pedal. What I initially did when there was no information around, was to mount the booster and see where it lined up with the pedal; then marked and drilled accordingly. The 2-3mm difference is what I also came up with after I installed it.

No ABS, neither did my VN

I'd expect your lines should reach the master outlets.

Cheers,

Jim.....

[Fonzie]

Join date 04, you're a veteran! Cheers for your response mate. I had a chat to another bloke on this forum a few days ago, can't remember his username... But he did the upgrade. He pointed me towards the JC User "Markovr", he sells the brackets or modified boosters/master cylinders for the job.
Fonzie

[VrWagz1]

Well, i cant contact the original guy who i got the design off for the bracket. So heres a badly done paint drawing on what i think the measurments were. Note that i didnt include the redrilling of the vt booster pushrod. The pushrod hole does need re-drilling back slightly at around 111-113mm from the base of the new modded bracket. But please check this first with a dummy install cause my memory has faded alot since i did this. Also im not sure what the new bolt hole dimensions were, so you gonna have to measure these yourself befor drilling.
Markovr, if ur still with us, could you maybe confirm/deny some of these measurements.
I have included a pictur of the finished setup, so you can see if what you are making is close to what it should look like

[Jimbo]

I'll see what I can dig up.

[nathanVY]

Good thread, wish it was around when I was looking at VT brakes. I have a VT Booster / MC with a custom mounting bracket for sale (and the rest of the conversion including shims) if anyones interested PM me

[Lazin]

Nice thread! a couple questions.
Whats the difference between the vs and the vt booster/mc (size, pressure, strength)?
Does it make the pedal firmer?
I have the vt brakes/rotors and my pedal feels softer and with longer travel.
Are any of the other models (vz, ve) bigger/better and will they fit?

[VrWagz1]

VS i believe is only a 3:1, whereas the VT is 4.25:1 boost ratio. Cant remember what bore size it is on the VT mc, it is bigger then 1" though from memory, whereas the Vs bore is only 7/8". VR booster is 4:1 with a 15/16" master bore. I guess the smaller bore in the VS is why they went backward in boost ration on the VS, but they were a plactic booster on the VS which just seemed cheap to me!
Yes i can sypathise with the long saggy pedal. I couldnt hack it, i had to do this conversion or rip the brakes back out. Pedal is way back up the top and its more responsive with the higher powered booster.

The "VT brakes"(Including booster and master) are all the same through to VZ(the booster you see above in mine is a VY). It only changed on the VE and i really know nothing about that. I am reading on here that the VE calipers and rotors are a better upgrade option for the VR/S due to them having a smaller piston in the calipers, that will run ok directly off the factory VR and VS booster/master. But its all hearsay, i have not seen heard of anyone yet to do it. All i do know is its not a direct bolt up job like the VT brakes, there is some adaptor brakets an stuff required to fit them.

[Not_An_Abba_Fan]

All this ####ing around for a system that isn't as good as the VE upgrade.

The VE package comes with everything you need to fit it to all earlier Commodores VB-VS. No drilling, cutting, welding or fabricating of any kind. And yes, I can vouch for this system being a purely bolt on improvement. I have sold numerous kits and have has positive results from everyone of them. There was a slight problem as to the fitment under 16" rims for one person, but the RDA admitted they made a mistake and a full refund was given.

[CRCinAU]

There was a slight problem as to the fitment under 16" rims for one person, but the RDA admitted they made a mistake and a full refund was given.

Mistake being what? The kit won't fit under 16" rims or something else?

[VrWagz1]

All this ####ing around for a system that isn't as good as the VE upgrade.

The VE package comes with everything you need to fit it to all earlier Commodores VB-VS. No drilling, cutting, welding or fabricating of any kind..

Thats why i mentioned it. If the VE works with the vr booster then this is all redundant. At the time this thread was created there was no VE upgrade. Thus the lack of interest in this thread bar the fewq Q's i been asked, which i updated the thread for. Not having yet experianced it then i cant comment. I would like to hear from someone ho has had the VT upgrade and moved to the VE to give feedback on the difference.
The only thing this has over the VE(if there is equivilant braking power between them) is price. VT calipers/rotors , booster/master, hub ring adaptor, will set you back about $250 in second hand parts. Whereas the ve is mostly having to be bought new and adaptor plates are required and i beleive are at a fairly significant cost well in excess of $500 (you ay be able to enlighten us there since you retail them NAAF). So if money is a problem and time is not (say 8hrs to fit vt calipers and rotor, then make bracket and fit vt booster/master), then the VT is significantly cheaper.