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Technical help

How to adapt the VT Master Cylinder to early model Commodores

Started by RB30-POWER · 13 Apr 2008 · 339 replies

Preserved from CalaisTurbo (partial recovery). Original authors and dates are shown; archived members are not current Holdcom accounts.

86 gmhArchived member
Whats the reasoning behind cutting the head off the adjusting screw? just interested know is all.
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WaughyArchived member
It's so the VT master will mate flush with the VS booster. If you don't want to cut it there is an adapter plate you can buy.
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86 gmhArchived member
Ah ok it all makes sense now.Picked up the vt master cylinder today and yep it sits flush on the booster.
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-HOLDEN-Archived member
anyone find cheaper line adaptors from anywhere?? HS wants 65 bucks for 3
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madrx3boyArchived member
Quote: Originally Posted by -HOLDEN- anyone find cheaper line adaptors from anywhere?? HS wants 65 bucks for 3 u serious? I paid Hoppers about NZ$100 for 2 sets incl shipping, that was in April this year. I think they were about AU$35 per set. 65 is heaps. Also guys, just to confirm, I went to the wrecker today to get a reservoir from an AU Falcon (they gave me a BA Falcon one, apparently its the same). And it fits perfectly, (I haven't got the setup in the car yet but the back of it is much higher than the VT one, so it's definitely gonna sit a lot more level when its in the car). cheers Sam
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wilson33Archived member
Quote: Originally Posted by 5spdvl Ok, got a response from Race Brakes Sydney. The kit they do is for the VT master and VT metal booster (twin diaphram), not a VS V6 booster. I was quoted $690 delivered. So it all depends on what booster you want to use. So is using the VT twin diaphram booster too hard to bother? What needs to be done to use it? I was told the VT booster would be the best option possible, but VS V6 sounds good after reading this thread. Im thinking of just getting the parts new from Holden as you enquired about as they look much cleaner and neater, and ill know what im getting for sure so no confusion as to what parts ive actually got like some people have had. With the VT master, what has to be done with removing the 'bung' or something in the 3rd hole? Some original photos have not been recovered yet.
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madrx3boyArchived member
To use the VT booster you need to make up a bracket to mount it to the firewall. (The bracket on the VT booster has different mounting points to the VS and VL boosters). There was a guy who had a web page showing how to make up the bracket. Search on here and google 'project VN Aero' . http://users.bigpond.net.au/jimbo123/VN/ That's the link to the guy's webpage but it doesn't seem to be working at the mo, you may want to try later. Otherwise I wouldn't know. And the 3rd hole on the VT master, Yes I'm pretty sure that bung has to be removed (the VT had ABS which meant it only had 2 lines running from the master to the ABS unit) Someone please correct me if I'm wrong. cheers Sam
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-HOLDEN-Archived member
the bung is just a small bolt that needs to be taken out, above is correct, vt master, vs booster, vt big brakes, works amazing
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wilson33Archived member
OK i just wasnt sure what was involved in removing the bolt to allow the 3rd brake line to work on the VT master. I was worried you had to drill something out ect. So what makes the VS V6 booster better than the standard VL booster. Would a VL V8 or even VP V8 booster be better again, or is there something about the VS design that makes it better than previous models? Is the VS V6 booster big enough to work with powerful V8's and turbos ect? Just i have a VL V8 and i though to be legal i had to run full V8 brake setup, so i assumed this included booster aswell.
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jbonezArchived member
You will find the major benifit is the master cylinder being able to attach to the vs booster, being a bigger bore & fast fill master. Vs is the easy route if you are really worried about the performance (which is a massive upgrade to the vl turbo/v8 setup allready) then just spend the money to modify the vt booster
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Com_VCArchived member
Quote: Originally Posted by -HOLDEN- anyone find cheaper line adaptors from anywhere?? HS wants 65 bucks for 3 Did you end up finding them cheaper?
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DENTEDArchived member
i just finished the up grade. big improvement on the 1" standard. sydney race brakes has the adapters for 15 each. the VS Master Cylinder Reservoir Part No. GM-VS21166, is no longer available from holden.
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madrx3boyArchived member
Which brake lines on the VL go to which holes on the VT master cyl? I can figure the rear one out because it has a bigger fitting, but what about the fronts?
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madrx3boyArchived member
anyone?
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-HOLDEN-Archived member
its dosent matter dude, the same pressure go to each brake caliper, com vc i just got them from race brakes syd, 15 bucks each, the entire conversion cost me like 160 bucks, vt calipers and vt/vs master booster
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Peeekn 86Archived member
Quote: Originally Posted by madrx3boy Which brake lines on the VL go to which holes on the VT master cyl? I can figure the rear one out because it has a bigger fitting, but what about the fronts? I had same drama but there both the same once the piston inside the master goes up it pushes brake fluid out at the same time to the fronts so it doesnt matter wich is left or right.
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madrx3boyArchived member
ok cool, thanks guys
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madrx3boyArchived member
Put my VS booster and VT master on yesterday, didn't have too many problems, just a few thing to watch for tho. 1) Even after cutting the head off the pushrod screw, it still didn't go in all the way. I think the thread on the inside of the pushrod doesn't go all the way down. so I had to cut another 4mm or so of the screw. 2) The support bracket where it bolts to the strut tower - even tho the car is N/A that bracket still had to be modified - had to drill the 2 strut tower holes closer in to the bend in the bracket - which meant I could cut a bit off (the section where the 2 old holes were). The hole where it bolts to the master cylinder is still the correct distance away from the strut tower, so no probs there. 3) I used the brass adapters, but for the 2 smaller ones (front brakes) there is no point using the washer that Hopper Stoppers supplied, because the lines are supposed to seal on the flare, not with a washer. HOWEVER, the big adapter for the rear brake line was flared on the inside (where the old brake line screws into) but it wasn't flared on the bit where it screws into the master cylinder. So I did use a copper washer on there. 4) Finally, the pipes have gotta be bent around a bit, you really MUST use a pipe bending tool, the tool keeps the pipes in a circular shape, if you try to do it by hand they will kink (my Dad did mine for me), the tool we used was a bit of a pain to get at the lines with as theres not really enough room for it. but he got it done 5) Oh one more thing, the nuts holding the M/C to my old booster were 16mm I think, but the VS booster takes 13mm nuts and washers. So I grabbed the old VL booster and pulled 2 sets of the nuts and washers off the bracket which holds it to the firewall All in all, it wasn't too much work getting it all in. can't try it out yet tho, my rear end is getting re-bushed and painted and still have to put the rear brakes on and the new VT fronts, I'll let you know once it's done. Some original photos have not been recovered yet.
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-HOLDEN-Archived member
num 2, could of used the VT MC braket and just turned it around, its a perfect fit, and i did num 4 by hand, just follow where the original bends are and it should be fine, mine are lol
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Com_VCArchived member
I used VS brake lines for the engine bay was easy as, now I only need to buy one adapter for the rear line.
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