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Master cylinder

Hi guys new to the site. Just like to ask, i am converting my front drum brakes on my EH to LH torana discs using the adaptor plates and maintaining the kingpin front.
Would like to know am i able to use the same master cylinder with the VH40 booster? or do i need to change it to a HQ master cylinder? Thanks.

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no i asked similar question.

no i asked similar question.

Do not argue with an idiot. He will drag you down to his level and beat you with experience..

no itll be fine..

no itll be fine..

Do not argue with an idiot. He will drag you down to his level and beat you with experience..


If you do retain the drum brake master cylinder you will need to remove the residual line pressure valve from inside the cylinder. Take it to your clutch and brake guy and ask him to do it. It's a 2 minute job and shouldn't cost much. If the cylinder is shot and you are going to buy a new one buy a clutch master cylinder instead of a brake. This one does not have the valve fitted but otherwise is identical. The valve was fitted to keep a small amount of pressure on the shoes in the drum brake keeping them close to the drum and avoiding a long pedal trying to get the shoes to contact the drum.. If you boost the entire brake system also make sure you change the rear wheel cylinders to HR disc brake front rear cylinders. If you don't you WILL have rear brake lock up problems.

Thanks for the info. So if i

Thanks for the info. So if i have the valve removed then run the line from master cylinder to booster from booster to the that little junction where the brake lines meet and change brake cylinders it will be ok? With the HR cylinders, would they fit ok without any probs with the shoes? I was also told to use a HQ master cylinder, run the front outlet to the booster and the rear outlet to the rear brakes.

Just run the line from the

Just run the line from the master cylinder to the booster and back to the firewall junction. You shouldn't need a HQ master cylinder.
You will need HR brake shoes on the back with the discs as they are different to EH shoes where the wheel cylinder pushes on them. The EH has a little pushrod between the cylinder piston and the brake shoes whereas the HR cylinder piston pushes directly on the brake shoe - that's how I remember it working.
The HR rear cylinders and shoes go straight into an EH.
One question myEH could probably answer: Do the LH calipers have a bigger fluid capacity than HR calipers? If they do will a HR type discs master cylinder push enough fluid into the LH calipers for them to work properly - especially with worn down pads? This could be why someone said you need the HQ master cylinder.

Old is good.

No problems

should'nt be a problem with the single ciruit master cylinder and Torana calipers. Volume wise, as the caliper piston moves out through pad wear the master cylinder adds fluid from the reservoir. More pad wear equals overall greater quantity of fluid in the system. Just keep an eye on the fluid level in the reservoir..
Personally I'm not a lover of a single circuit system if a dual circuit is easily available. Just a general safety thing. I would go for the HQ setup with a VH40 on the front circuit and unboosted rear circuit. OR the same dual circuit system as above with the commodore rear disc setup and a VH44 added to the rear ciruit.

I think i might go with the

I think i might go with the HQ set up. Even thou the other way is cheaper.The adaptor plate alone for the HQ master cylinder is $300.
Thanks guys your comments are very much appreciated.

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