278 replies to this topic

[SLR576]

Thanks Ausdev,
I just followed these instructions and all fitted spot on!!
Cheers

[dron]

The uc caliper (alloy) with the steel part that holds the pads from the same age H series car will work. I have both here somewhere.

 

I was going to go that way but ended up with the UPC compleat big brake kit, Worked and fitted well.

 

If any one wants the calipers, New HQ disks, Drumb stubs with the hq caliper mount from CRS let me know thay are just colecting dust now.

[dron]

The uc caliper with the hz support to allow for the thicker vented disk.

 

If you use the hz caliper the bleader will be in the wrong place. The alloy section of both is the same except for the bleade screw location.

[yel327]

Not quite right. The Holden caliper has the brake hose underneath, the Torana one has it on the top. Bleeder should be the same.

[UCSLE]

Hq discs on torana stubs is a crap conversion and depending on the caliper it can dangerous

 

the disc wont line up correctly , using a UC caliper with  HZ support will probably drag the outside pad 

 

there is two types seals for UC caliper that go on the slides , one has boots the other has o-rings

the boot style caliper will drag the pad more

 

using something like a HQ caliper can have the inside pad fall off the cradle as the pads / discs wear down

[Toran the Carbarian]

Hq discs on torana stubs is a crap conversion and depending on the caliper it can dangerous

 

the disc wont line up correctly , using a UC caliper with  HZ support will probably drag the outside pad 

 

there is two types seals for UC caliper that go on the slides , one has boots the other has o-rings

the boot style caliper will drag the pad more

 

using something like a HQ caliper can have the inside pad fall off the cradle as the pads / discs wear down

I'm not having a go but am genuinely interested as to what you think is a less crap and safer upgrade to front brakes if I want to keep 13" rims. Cheers

[RallyRed]

A liitle off topic maybe...The go to conversion for the LJ Group N track cars is vented BMW rotors and Volvo twin spot calipers.
Established, effective, bolt on, fits 13 " wheels and can be purchased as a package for around ?? $1500.

Edited by RallyRed, 11 November 2019 - 01:39 PM.

[UCSLE]

stay standard

[VinnieSLR]

I want to upgrade my 77 LX Brakes and go the full HQ option. Previous owner did the version of grinding down HQ Discs but used LX front calipers...so other than having ventilated discs and HQ stud pattern for wheels there isn't much benefit it seems. The way previous owner did it also caused an issue with the brake pad being to big and slightly grinding into the hub, but have fixed that now.

So if I want to do the full conversion, like an A9X would have had, are these the following items I'll need:
- HQ-HZ Disc/Hub
- HQ-HZ Stub Axels (does it matter if disc or drum Axel's?)
- HQ-HZ Calipers
- Harrop Steering Arms (already got these stored away)
- Custom/Lengthened brake lines
- Modification to the Master & Slave Cylinders??

I think I might be missing a few things but not sure?

When doing this I understand it can drop the cars height by 20mm, but is this at the front only? I would assume so.

Also, what would be required for the rears? I currently have a 9" with HQ Drums but want to be sure it has been done correctly.


Cheers

[yel327]

I want to upgrade my 77 LX Brakes and go the full HQ option. Previous owner did the version of grinding down HQ Discs but used LX front calipers...so other than having ventilated discs and HQ stud pattern for wheels there isn't much benefit it seems. The way previous owner did it also caused an issue with the brake pad being to big and slightly grinding into the hub, but have fixed that now.

So if I want to do the full conversion, like an A9X would have had, are these the following items I'll need:
- HQ-HZ Disc/Hub
- HQ-HZ Stub Axels (does it matter if disc or drum Axel's?)
- HQ-HZ Calipers
- Harrop Steering Arms (already got these stored away)
- Custom/Lengthened brake lines
- Modification to the Master & Slave Cylinders??

I think I might be missing a few things but not sure?

When doing this I understand it can drop the cars height by 20mm, but is this at the front only? I would assume so.

Also, what would be required for the rears? I currently have a 9" with HQ Drums but want to be sure it has been done correctly.


Cheers

You pretty much have it covered. You need:

HQ-WB rotors
HK-WB disc brake stub axles. L34 and A9X used the heat treated cab-chassis ones but not needed for a street car.
A9X steering arms

What hoses you need depends on the caliper.

If you have a 9” with HQ-WB drums all good, will just need the right wheel cylinders. Datto will be able to tell you which. Pretty sure your current master will do the job, but again check with Datto.

Caliper choice, there is probably only three original Holden ones:

HQ (all fast PBR). This is what L34 used but they were machined for a top entry hose.
HX PBR. Not a popular caliper but the only straight bolt in if you make a hybrid out of HX and UC (HX pad carrier and UC alloy caliper). I used to run these and they work OK but some people don’t like them.
HZ Girlock. As used on A9X but modified to clear the tie rod ends.

There may be a donor caliper that works too. Hoppers might have a suggestion.

HK-WB stubs do drop the front about 1” from memory. Might be a fraction less.

Edited by yel327, 15 December 2020 - 08:40 PM.

[VinnieSLR]

You pretty much have it covered. You need:

HQ-WB rotors
HK-WB disc brake stub axles. L34 and A9X used the heat treated cab-chassis ones but not needed for a street car.
A9X steering arms

What hoses you need depends on the caliper.

If you have a 9” with HQ-WB drums all good, will just need the right wheel cylinders. Datto will be able to tell you which. Pretty sure your current master will do the job, but again check with Datto.

Caliper choice, there is probably only three original Holden ones:

HQ (all fast PBR). This is what L34 used but they were machined for a top entry hose.
HX PBR. Not a popular caliper but the only straight bolt in if you make a hybrid out of HX and UC (HX pad carrier and UC alloy caliper). I used to run these and they work OK but some people don’t like them.
HZ Girlock. As used on A9X but modified to clear the tie rod ends.

There may be a donor caliper that works too. Hoppers might have a suggestion.

HK-WB stubs do drop the front about 1” from memory. Might be a fraction less.

Champion, thank you 👍
Might check out hopper stoppers for better calipers.

[VinnieSLR]

Would I be ok with keeping the stock control arms and tie rod ends etc? Or do they also need to be changed?

[rexy]

I recommend staying with what you have and instead explore pad options.

it will handle much better keeping the Torana stubs in it.

[VinnieSLR]

I recommend staying with what you have and instead explore pad options.
it will handle much better keeping the Torana stubs in it.

I would have thought going the HQ option, to make it like an A9X, would have been the best for handling?

[rexy]

It certainly wasn’t my experience in my hatch. Drives a lot nicer now that I have put the Torana stub axles back in it.

[waynec]

need some help on this one guys ,

 

 

HQ Disk machined down HQ pbr caliper ,  standard LX stubs , caliper bracket hitting on tie rod end is this a common problem or am i doing something wrong here , ? 

ground a fair bit of the bracket still touching any help please ..

 

Wayne.

 

maybe caliper  better of at rear of disk ?  or dose that create more problems 

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[purrlx]

What steering arm do you have, UC drop down lower and the A9X drop even further. There is a pics of the 3 somewhere on here.

[waynec]

Lx as suggested in this topic

[Bigfella237]

Yeah but you have to use the correct steering arm for the suspension setup otherwise you'll induce bump steer.

 

The UC steering arm socket is lower because of the UC upper control arms, and the A9X is lower still because it has the UC-style UCAs plus the HQ-style stub axles with the 'drop-spindle'.

 

You can't just mix 'n match to suit the caliper clearance.

 

 

 

[waynec]

might try swapping stubs  left to right right to left ,

 

put the caliper at back of disk

Edited by waynec, 24 February 2021 - 12:30 PM.

[yel327]

It will hit the crossmember. I had the same problem originally back in the 80’s.

[waynec]

Yeah but you have to use the correct steering arm for the suspension setup otherwise you'll induce bump steer.

 

The UC steering arm socket is lower because of the UC upper control arms, and the A9X is lower still because it has the UC-style UCAs plus the HQ-style stub axles with the 'drop-spindle'.

 

You can't just mix 'n match to suit the caliper clearance.

 

 

 

so if i get uc steering arms it should fix the problem ?