14 replies to this topic

[neglectedtorana]

In the interest of having a firmer pedal and quicker response from the brakes I am looking at a VT master cylinder, easiest way to make it work would be to fit a VT booster.

 

The VT booster is a bigger diameter than my Torana booster (which has a VN front) and I don't think it will fit without touching the top of the rail. With my Torana booster I have about 5mm clearance to the rail and it is 232mm diameter and the VT booster is 248mm diameter.

I have seen a VT booster conversion on market place and I enquired and was told the mounting studs get lowered for clearance and it ends up very close.

 

Has anyone fitted a VT booster?

I could get an adapter to mount the VT master to my booster but it would ten move the master closer to my coils and I would like to avoid that.

[neglectedtorana]

I have considered getting a convex dolly or something and giving the rail a tap for clearance

[76lxhatch]

Was looking at this myself recently while waiting for parts for the custom-modified master cylinder, and trying to measure one accurately while still fitted to a car... gave up.

 

But, I think if you only needed to gain a few mm clearance then perhaps a wedge spacer between booster and firewall might do the trick without changing the pushrod angle enough to matter?

[neglectedtorana]

The wedge idea is one I was thinking of, the VT booster rod is straight so would need to be bent down to meet the pedal and unlikely but it could be just the right amount with a wedge. Not sure if it would affect the master cylinder but in my mind it's unlikely to cause any issues.

 

I did manage to remove my current booster without disconnecting the hard lines at the master cylinder and try to fit the VT booster in I think an extra 10mm would be all that was needed.

 

If I used the dolly it wouldn't need to move much metal re-shaped and it would be fairly out of sight under the booster. 

 

What sort of tools are needed to open a booster?

How is the metal crimped where the 2 halves meet?

[yel327]

I'm not clear on why you wouldn't just use the Holden or Torana booster and the little adapter required? That is what I've done with my HK. I have to make new hard lines anyway, not that much work. I need the VT cylinder due to the BA Falcon calipers on the Rodtech front end.

[76lxhatch]

What sort of tools are needed to open a booster?

How is the metal crimped where the 2 halves meet?

Most PBR steel boosters you just need to rotate the front and rear housings and they will pop open. Watch out for the return spring, they can have enough force to launch parts a short distance. Best if you have a means of holding it in a bench vice and applying a bar to the other side (bolted on solid).

[neglectedtorana]

Most PBR steel boosters you just need to rotate the front and rear housings and they will pop open. Watch out for the return spring, they can have enough force to launch parts a short distance. Best if you have a means of holding it in a bench vice and applying a bar to the other side (bolted on solid).

Thanks, wasn't sure if the crimped sections were done while holding the 2 halves
I can make something to undo it I think

[neglectedtorana]

I'm not clear on why you wouldn't just use the Holden or Torana booster and the little adapter required? That is what I've done with my HK. I have to make new hard lines anyway, not that much work. I need the VT cylinder due to the BA Falcon calipers on the Rodtech front end.

If I ad a spacer/adapter to my current booster it will move the master cylinder further forward and will end up too close to my coils
Plus it would be much neater without the spacer/adapter

[yel327]

If I ad a spacer/adapter to my current booster it will move the master cylinder further forward and will end up too close to my coils
Plus it would be much neater without the spacer/adapter

 

Ah, I didn't think of the cosmetic angle! What booster is there now?

[Balfizar]

Thanks, wasn't sure if the crimped sections were done while holding the 2 halves
I can make something to undo it I think

VT to VZ dual diaphragm booster (and probably any after that) are listed as a non-serviceable part.

No amount of twisting of the backing plate will find relief notches (unlike earlier boosters.)

Because there aren't any.

Attached Files

•  VT Booster Backing plate 001.jpg   298.96K   1 downloads

[neglectedtorana]

Ah, I didn't think of the cosmetic angle! What booster is there now?

 

Rear half Torana front half VN so the master bolts directly, 

VT to VZ dual diaphragm booster (and probably any after that) are listed as a non-serviceable part.

No amount of twisting of the backing plate will find relief notches (unlike earlier boosters.)

Because there aren't any.

 

That's interesting, I have spoken to a brake shop that will modify the booster to suit Torana and I think it means opening it to put in different mounting studs and swapping the pedal rod

[yel327]

I'm pretty sure the upgrade booster I fitted to my Hilux was a modified VT booster.

[dattoman]

Rear half Torana front half VN so the master bolts directly, 

 

That's interesting, I have spoken to a brake shop that will modify the booster to suit Torana and I think it means opening it to put in different mounting studs and swapping the pedal rod

 

 

Can defiantly rebuilt VT-Z units

We do it at work all the time

[Balfizar]

Can defiantly rebuilt VT-Z units

We do it at work all the time

Datto - how do you get it apart and what spare parts and method do you use to get it back together?

[Balfizar]

There are 15 depressions that are pressed into the outer shell that would need to be flattened back out to release the rear booster plate, then the rear booster plate would need to be clamped in place while the depressions were pressed back into position to secure the rear plate.  Very messy job without a jig.  I am not sure bending the depression out and back in is a good option. Maybe that's why GMH listed the booster as unserviceable.  But! it could be done.  Spare parts "unknown"