56 replies to this topic

[Lc69]

Hi guys,
I've just joined but have been using the forum for a while now for info. Thanks, it's been very helpful so far!
I'm in the process of doing some work on my new LC 4 door.

I've just found that my master cylinder and booster both need to be rebuilt/replaced.
I already planned to do the hopper upgrade on the front and I have a set of VS commodore backing plates and handbrake assemblies for the rear. I planned to modify the backing plates to clear the shock and then rework axels for commodore stud pattern.

So I basically haven't purchased many parts and I'm up for a complete brake rebuild.

I should mention I'm considering a V8 upgrade at some stage. So booster clearance may be important.

Can anyone suggest a good combination that can be easily engineered and isn't too exotic?
Any advice would be appreciated.

Currently thinking:
Hopper front brake upgrade, commodore stud pattern.
VS commodore rear disks, modified backing plates and axels.
XU1 booster
Unsure on master cylinder? Rebuild or replace current?

[Lc69]

Point taken. I'm sure they find it easier when it's a straight conversion.
Front brakes will be AU ford I believe. I don't think that should be an issue.

I've seen the post on using a VR dual diaphragm booster and master cylinder on LH/LX.
Anyone done this on LJ/LC?

[Lc69]

i need to get a new booster and ms anyway so I can get something that suits the 4 wheel disk brakes rather than buy an original ms and modify it.
Mind you, maybe it's easier to do this than to change lines to metric at the ms?
There's the extra issue of the brake warning switch, do the newer ms have these as standard. May be a requirement if I upgrade?
I should highlight I've just upgraded the dash an installed the brake warning light just in case.

I'm not sure the silver fox would agree with you regarding your mirror trick, ha ha

[Lc69]

It sounds like it will be more straight forward to use original options compared to a commodore setup.
I.e Upgrade the booster to a dual diaphragm VH324 and fit a new Master Cylinder.

The original master cylinder is a P6613.
I assume I can use this model again or maybe a P7210 as long as the push rod length is matched to the booster?
Then if I understand correctly I can remove the rear valve when I put the disks on the rear.
All the lines should have the right thread and bolt up.

So I'm just not sure which master cylinder is the best to use.

I'm also wondering if I should fit the later model distribution block with the switch. Probably not a bit deal, can do this anytime.

Any insight would be appreciated.

My old MS is full of mud, and the booster is full of fluid. Probably not worth much I guess?

[mick_in_oz]

I'd consider a few things,

 

Go with HQ stud pattern as there is a greater choice of wheels with a bit more dish that are in keeping with the older car, and if the axles are still 7/16" stud the commodore disk will fit, only need a hub ring to locate it correctly, or get the axles made to suit.

 

Change the front of the booster to an early commodore one, and then use the commodore master cylinder with the proportioning valve built in, cleaner, less plumbing, available to suit disk-drum or disk-disk, make a new push rod if the old one doesn't suit the new cylinder.

 

You could consider a 15/16" master rather than the typical 1" to help with peddle effort if you have to stick with the small booster for clearance issues.

 

You could also use an electric vac pump to supply the booster so that you again have enough assist using the small booster and the potential lack of vacume depending on how modified the engine ends up.

[Lc69]

Yeah I'm still considering stud pattern. Still trying to decide which way to go on wheels, so this will probably push the decision one way or the other.

LC/LJ don't have a proportioning valve as I understand it. Just a distribution block.
Some have the pressure switch, but is just a block as its a 69 model and didn't have the warning light.
I was thinking about fitting one of these as part of all this.

I've seen a few people talking about fitting a VB commodore front half and booster.
Not sure if this can be done on the LC/LJ booster? Is the diameter the same?

There seems to be a millions options. The standard option seems to be the simplest approach for the same results.
Will be contacting HydroBoost and Hoppers again to confirm.

Might post some pics if I ever make a decision and do something, then someone else can have one more option to consider ha ha.

[Lc69]

Going with the 9" dual diaphragm booster, modified to fit the P10500 master cylinder.

[Lc69]

Let's try uploading a picture of things so far

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[Lc69]

The check valve clashes with the horizontal fluid bottle (not the std P10050)
At this stage I think I'll mount the booster upside down to get away from this.
I have another check valve on the way that may work, but everything fits fine when the booster is inverted.

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•  image.jpg   289.36K   12 downloads

[Lc69]

Check valve when booster is inverted

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•  image.jpg   283.83K   10 downloads

[Lc69]

Brake lines are out and I'm about to get new ones made.
Brake kit is ordered from Hoppers
I'm waiting and waiting and waiting for a check valve to arrive before finally fitting the booster.
Never have much luck using Amazon.
Suspension has been cleaned and I'm working on the painting.
Need to fit new bump,stops and chasis mount bushes as well.

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[Lc69]

Also picked up some 17inch steel wheels for trial fitting.
Fitting two tyres this week so I can get a good idea how much clearance I have

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[Lc69]

I've fitted tyres on two of the wheels for a trial fit.
I'm sticking with my original plan and going with 195/40 front and 205/40 rear
This picture shows the 195's. Don't have the 205's fitted yet.

The wheels are off a Hyundai IX35, 17x6.5 +51
I plan to eventualy fit 6" front and a 7" rear.
The rear wheels are easy sourced, the fronts will need to be custom.

I'm using adapters for the trial fit because I haven't upgraded the brakes yet.
I'll let you know the final offsetting-backspace I settle on once everything is fitted up properly.
I have just thrown everything together so I could make sure I was on the right track before fitting the next pair of tyres.

I'm going with a 5x4.5" stud pattern. Why?
More wheel choices, closer to the Torana stud pattern so the rear conversion will be easier, and I can run a standard F🤐rd front rotor.  image.jpeg   127.16K   9 downloads

[Lc69]

Those 17" steelies will look frOcking awesome with some trim rings. 

Yep, already Have a set in the mail.
Also looking at fitting the original centre cap.

[Lc69]

Hopper kit arrived this week.
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[gtrboyy]

Like the look..gtr caps were too small to bolt up to hq or commo pattern if memory serves correct.

 

Always wondered if gtr cntre caps could be modified/extended to fit...the metal on them looks thin & crappy though.

[Lc69]

Like the look..gtr caps were too small to bolt up to hq or commo pattern if memory serves correct.
 
Always wondered if gtr cntre caps could be modified/extended to fit...the metal on them looks thin & crappy though.

I haven't spent much time on it yet. I don't want to modify the caps.
The PCD is a bit different but I'm thin inking I might be able to modify the wheel nuts and/or make an adapter.

[Lc69]

Those 17" steelies will look frOcking awesome with some trim rings. 

Put one on for a quick look

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[Lc69]

Measured the hoppers kit against the original today. The from track increases by 4-4.5mm each side. Not as much as expected and looks to give really good wheel clearance.

[Lc69]

Thanks mate, I'll try and get some decent pictures of it on the ground soon.

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