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SO WHATS STOPPIN’ YOUR HOLDEN?
By Peter Koning of Hoppers Stoppers
From the amount of enquiries we receive via the Internet, fax or phone, it
seems that Holdens from 1950s, to 70’s, and Torana’s, are as popular as
ever with modifiers, particularly with the rising popularity of fitting
injected V6 and V8 Commodore engines.
As pre
1976 ADR27 cars can be legally modified with no worries about EPA
pollution control laws, the Australian love of hotting up an old Holden
looks set to continue for a long time.
Us
older guys were brought up playing on our EH’s and FC’s but as the next
generation continues the tradition, it seems the tricks of swapping front
suspension and brake parts needs to be passed on. The older amongst us
will probably know most of the following but for the younger guy just
starting on his first “early” the mysteries of the King Pin and Ball Joint
front suspensions might use some explaining. So here’s some now.
History -What’s
Holdin’ Up Your Holden?
From
their release in late 1948 with the 48/215 (FX) up to 1964 with the EH,
Holden’s used what was commonly called the King Pin front end.
This was a double A
arm suspension, featuring pressed steel “unequal length” upper and lower
control arms, pivoting off a removable pressed steel cross member which
was bolted to the body at four rubber insulated mounting points and from
FE onwards reinforced against torque by a nose section that bolted under
the radiator support member.
The stub axle pivoted
on a vertical pivot pin (the King Pin) and allowed for up/down movement on
upper and lower steel bushes at each end of each control arm. Counting all
the bushes and tie rods there are 28 greasing points on an early Holden
front end, which needed to be lubed every 2000 miles! These king pin
suspensions were tough as nails, but once worn rebushing the kingpins was
not a cheap exercise.
By the late 50’s the
Americans were replacing Kingpins with Ball Joints, and this caught up
with Holden’s in 1965 with the HD model. The upper and lower outer pivots
and kingpins were now combined into a lubricated spherical ball at each
end of the stub axle. In Holden’s case the lower ball joint was pressed
into the arm from underneath, and held there by the spring load, the upper
joint was fitted from above and originally riveted in, but replacement
upper ball joints bolt in, once the rivets are drilled out.
Midway through the HD
run Holden introduced that wonderful invention, the DISC BRAKE ! As this
had become popular on European cars in the early 60’s we might have
wondered why it took longer to reach here. However Holden is an American
owned company and the Yanks didn’t really see Discs until the late 60’s,
relying on their favorite drums even longer than we did. Being a thin
solid rotor we now look back at the HD/HR discs as a bit feeble but
compared to drum front brakes it was a huge improvement. Actually Holden
had Disc Brakes a bit before Falcons and Valiants, so being the first of
the big three they didn’t do too bad.
It didn’t take long
to realize that the HD/HR ball joint front end could be adapted to fit any
FX to EH. You needed to relocate the engine mounts and weld on the correct
nose extension, and then they would bolt in. Being an option not many HR’s
got them, but disc brakes for early Holdens were easy once those highly
desirable disc brake HR’s began reaching the wreckers.
With the bigger HK to
HG range discs became more popular, even standard on V8 cars, but most 6
cylinder cars were still built with those basic old drums. HK’s had steel
inner pivot bushes, then with HT/HG we got rubber bushes for a quieter
ride and maybe a few dollars saved on the assembly line.
With the introduction
of the HQ series Holden went to a half chassis style front end, the
cross-member and front half rails being all one welded piece bolted under
the base body shell. Steering went to the front of the cross-member and
whilst still using unequal length control arms the bushes were bigger and
softer, with design favoring ride over handling.
HQ’s got Holden’s
first decent brakes; optional 11 inch ventilated front discs, with rear
drums retained for a long time yet. The majority of HQ’s would have had
front discs fitted.
With the HJ range
front discs became standard, and that’s the way things basically stayed
until rear discs became optional on HZ. (Standard on GTS)
The last of the big
Holdens, the WB, had four wheel discs standard on the Statesman’s but
drums on rear for utes and vans. My old PBR books show rear discs possible
on Commercials but I don’t know if they were ever actually built. With
their leaf springs I don’t believe those rear calipers would fit.
THINGS YOU MIGHT NOT
HAVE KNOWN ABOUT HOLDEN BRAKES
FX
to WB
At the risk of boring
the older guys who probably know most of this
already...................................................
1/ FX and FJ had 15
inch wheels with a large stud pattern, the studs being out toward the edge
of the drums. Rear axles have a taper hub/keyway drive which needs a
special puller tool to remove the drum. Master cylinder is under the floor
with a remote filling tin on the firewall optional.
2/ With FE ‘s Holden
went to 13 inch wheels with the familiar 4.25 inch by 7/16 stud pattern
and drums that could be removed leaving the rear axle flanges or front
hubs in place. Master cylinder went up on the firewall with “swinging
pedals”. Front and rear brakes were same width shoes.
Remote PBR VH24 power
booster was optional, with a warning sticker on the rear window so that
those with lesser cars would know not to travel too close!
3/ FB saw basically
the same design of brakes as FE/FC but with wider shoes.
4/ EJ saw brakes
changed to “Duo Servo” which means that the two shoes are joined by a
floating adjuster, so that the front shoe gets pulled into the drum by
rotation action, thrusts through the adjuster passing the load to the rear
shoe, making the brakes more self energizing and equalizing wear.
5/ EH brakes are the
same as EJ.
6/ HD/HR all got
wider front brakes, with the same rear brakes as EH on Sedans and Wagons.
However Utes and Vans came with wider rear brakes.
Same 1 inch master
cylinder as FE onwards, with a remote VH44 booster to all four wheels
optional.
Front discs were
introduced with HD, mid model, and larger VH40 “hydro-vac” remote booster
to all four wheels then standard with discs. Can someone tell me if discs
came standard with X2 and 186S Engines?
As discs are not self
energizing, rear wheel cylinders for cars with front discs are smaller
(9/16 compared to 13/16) also requiring a different rear shoe as the
smaller cylinder could not use a push rod. (The shoe has a different
profile so the wheel cylinder piston can bear straight against it)
As it was possible to
order a Ute or Van with front discs, there were therefore FOUR types of
rear shoes and TWO types of rear wheel cylinder used on HD/HR Holdens. If
converting your HR from front drums to discs, (and boosting all four
brakes like Holden did) you should also fit the smaller bore rear wheel
cylinders and matching shoes, or rear brake lockup will occur.
7/ HK went to 14 inch
wheels, of the same early stud pattern, with bigger diameter front and
rear drums, or bigger discs (but still solid) when fitted to the front.
Master cylinders went
tandem split system for safety, and “Master-vac” booster between firewall
and master cylinder for the first time. Drum brake cars could be optioned
with a fairly big master-vac and disc equipped cars had positively huge
boosters as standard. Brake fail switch now fitted.
As per HR, rear wheel
cylinders were smaller bore and rear shoes were different when front discs
were fitted.
V8 equipped HK/T/G had
a thicker disc rotor than 6 cylinder cars, with a 1/8 spacer plate
inserted in the middle of the caliper to allow the same basic caliper
bodies to be used.
8/ On HQ front drums,
size, shoes and wheel cylinders were identical to HK/HG, but now with 4.75
by 7/16 (Chevy) stud pattern.
Rear drum shoes and
cylinders were same as the HK/HG four wheel drum brake type for all cases
(using 7/8 wheel cylinders)
HQ had a brake fail
switch on the top control arm inner bolt with a proportioning valve half
way along the chassis.
HQ to WB disc brake
stubs are functionally identical to HK/T/G but the tooling wore and was
replaced over time so they do have differences in appearance.
HR disc stubs had the
bearing center line 1 inch down, so fitting HQ stubs lowers your HR 1
inch, but the caliper mounting ears are further out and closer to the
center of the car so you must use HK to WB calipers and matching rotors if
fitting these stubs to a HR. As HR use 13 inch wheels this also means
14inch wheels and /or HQ stud pattern.
9/ With HJ the
proportioning valve was combined with the switch, and fitted at the top
control arm. Prop valves now have different settings for sedans, wagons,
Statesman’s, and Commercials.
Half way through HJ
series Holden changed to a different caliper type, with a long and short
pad, and flat slide arrangement.
10/ Half way through
HX another caliper change, this one had the slides on tubular sleeves,
which were at the fixing bolts, probably the worst of the HQ to WB series.
11/ Half way through
HZ, the Girlock “Collette” type caliper introduced, this has the alloy
body and slide pins out at the edge of the caliper. This same basic
principle is still used by PBR to this day.
With HZ, rear discs
were offered, a different master cylinder with no rear residual valve and
different proportioning valve then used. Reportedly a different pedal box
ratio used for cars with four wheel discs, can any one shed some light on
exactly how this was done?
12/ The new VB
Commodore was released around the same time as the WB range. Most of the
VB brake design and thread types were then carried over to other Holdens,
(WB, Torana and Gemini.) For the WB metric brake fittings were introduced,
the master cylinder went to plastic reservoir, angled bolts, and metric
threads. Prop valve now in the master cylinder. Front calipers very
similar to HZ but with the hose now shorter and to the rear of the control
arms and on the side of the caliper, using a banjo bolt and 10mm threads.
Hoses all have metric threads but the earlier 3/8 threads retained on rear
wheel cylinders. WB rear calipers are not the same as HZ but very similar.
13/ Every Holden from
mid way through FE to WB and every Torana used the same wheel bearings!
(Commodore VB to VP too). Every Holden HD to WB including Torana used the
same ball joints.
HQ to WB and A9X all
had the same disc rotor. (DBA014)
HK to WB (and all
Commodore) 7/8 wheel cylinders are the same.
Holden were always
good at parts bin interchangeability when they could get away with it.
Torana LC to UC
First lets forget
about the four cylinder HB and TA Torana’s, these used the English
Vauxhall Viva 4 stud front end and are very different underneath from 6
cylinder LC and LJ.
With the LC 6 cylinder
cars Holden stretched the front structure and went to a much stronger
cross member with 5 stud EH based drum brakes front and rear. When fitted,
front disc brakes were similar to HR. 13 inch wheels used.
Torana and HR disc
stubs look very similar to HR but there is a 1.5 degree difference in
Kingpin Inclination (the angle between top and bottom ball joints measured
from the vertical) This means that fitting HR or HQ stubs to a Torana
causes the wheels to lean in an extra 1.5 degrees, and usually results in
alignment problems. Whilst possible to fit a 1 inch lower HQ stub (to get
the bigger vented brakes) also leads to steering geometry changes and some
bumpsteer.
Just like HR and HK,
LC/LJ had smaller bore rear wheel cylinders and different rear shoes when
fitted with front discs. For XU1 the discs were made thicker with a 1/8
caliper spacer, smaller but just like V8 HK.
LH/LX was a whole new
car; same body and brakes were used on 4, 6 and 8 cylinder cars. A few
poverty pack LH cars had drum fronts (same as LJ) but most cars had discs.
Front discs used same stub axle as LC/LJ but with new single piston
caliper and thicker solid rotor. Still 13 inch wheels with 4.25 stud
pattern.
Midway through LX a
different caliper like early HX used.
L34/A9X cars use HQ
style vented brakes and 14 inch HQ GTS wheels. Holden made a special HQ
style stub axle incorporating Torana KPI, and a special steering arm to
compensate for the 1inch lowering. Caliper type followed HJ or HX usage
and Holden had to grind metal to get them to fit over the steering arm. If
you try to fit them to the rear they hit the top control arm and the bump
in the crossmember on full lock, causing the pads to be pushed back and no
brakes next application. Rear brakes were larger HQ drums. Some later A9X
reportedly had HZ rear discs, but I’ve never seen one and they don’t show
in the PBR books.
All Torana’s LC to
early UC used similar 1 inch master cylinders with the metal lid. Quite a
few different boosters fitted, V8 were double diaphragm and not all
interchange.
Early UC Torana’s had
same brakes as late LX. . By this time Holden discovered that LH/LX front
brake hoses rubbed on tyres on full lock so UC front hoses were longer and
relocated higher on the inner mudguard.
Concurrent with
introduction of Commodore VB, later UC’s got a new angled bolt booster, a
plastic reservoir 15/16 master cylinder with combined prop valve
(identical master to VB) and Commodore style calipers on the same solid
rotors.
Fittings and hoses
went metric and rear wheel cylinders and shoes went identical to Commodore
with a different (now unavailable) drum. Was this drum the same as 4
cylinder Commodore, which did use Torana stud pattern?
Have
you ever seen one of these?
A small number of UC
Torana’s were made with a disc brake rear.
This looked like a
smaller HZ Salisbury disc rear with unique rotors and calipers, they took
13 inch wheels in the early stud pattern.
I’ve only ever seen
one, and couldn’t say how many were made.
Interestingly, the PBR
book shows two different part numbers for UC rear calipers, so its
possible that they had an imperial thread and a metric thread version like
HZ/WB. Try getting an aftermarket disc rotor for this one!
OK that’s a quick
outline of what occurred over the years before WB and Torana’s were
replaced by the new Aussie Icon, the Commodore, and but that’s another
story. Now, how can I make my Old Holden’s brakes better?
Bigger Brakes for
Holdens
OK here comes the
Hoppers Stoppers Plug!
Why did you think I
was doing all this anyway?
Lets start at the
earlier types, the 48/215 (FX) to EH.
Its not really that
practical to fit discs to the kingpin stub although it can be done with
brackets and Torana or HR discs. The better way is the time honored HR
ball joint front end conversion, as you can then do the following,
obviously then from FX to HR, or cars like street rods using HR front
ends.
HR front brake
upgrades in ascending order.
1/ HR opposed piston
cast iron calipers and thin solid discs, as standard on HR front end. (But
that’s only an upgrade over drums)
2/ Torana LC/LJ cast
iron opposed piston or LH/LX/UC floating piston calipers in their cast or
alloy types with Torana rotors will bolt on to HR stubs. Not much of an
improvement but you can still have 13 inch wheels.
3/ HK/T/G Stubs fit HR
fronts, giving a bit bigger solid rotor but you will need 14 inch wheels,
at least still in FE to HR pattern. Not much better than HR or Torana
discs.
4/ HQ stubs (being
same as HK/T/G) fit HR front ends, use HR steering arms, then you can fit
HQ to WB calipers but watch for clearance re top control arms and having
to grind a bit off the caliper brackets to fit over the steering arms.
This gives you 11 inch ventilated rotors but usually in HQ pattern unless
you are prepared to pay for blank rotors and then have them studded in
early pattern. Note that HR and HK/T/G use 2.5 wheel centers where HQ use
2.75, so if getting HQ blanks drilled it might be necessary to have the
nose of the rotor machined down.
5/ On a standard HR
disc stub we can fit our steel hub with normal Holden Taper roller
bearings and using a simple banana shaped bracket, bolt on 290mm diameter
by 28 thick rotors and twin piston PBR calipers. These are based on Ford
AU2/3 XR8 stuff with the rotors ex DBA and bought blank so we can do any
stud pattern at all.
(Don’t worry you
Holden Fanatics; these bits are PBR and DBA, not made by Ford at all.)
Minimum 15 inch wheels
needed, and watch for Simmonds wheels which will touch at the ring of rim
nuts, requiring an 8mm wheel spacer.
6/ A 330 by 28 twin
piston version of the above is available, minimum 17 inch wheels.
8/ If you have HQ
stubs on your HR front end we use a BA style 300 by 28 rotor, this is OK
with 15 inch wheels except for Commodore or AU offsets where 16 inch are
needed. Same problem occurs with Simmonds hitting calipers, and also
sometimes Weld Wheels, needing 8mm spacers. Basically the wheel hub must
not dish in past the hub face before it attaches to the rim.
9/ A 330 HQ upgrade is
available too.
HK/T/G front brake
upgrades
1/ HQ/WB calipers
and rotors bolt right on but watch for caliper to top control arm
interference. Same as above, this means either going HQ pattern or getting
blank rotors studded and/or nose diameter turned down.
2/ A 300mm by 28
BA/AU3 combo (as above in 8)
3/ A 330mm Upgrade (as
in 9)
HQ to WB front brake
upgrades
1/ 300mm by 28 BA/AU3
kit as per 8.
2/ 330 by 28 kit as
per 9.
Torana Brake Upgrades
1/ For LC and LJ, fit
LH to UC rotors and calipers. A bit of an improvement and can still use 13
inch wheels.
2/ Find a genuine A9X
at the wreckers and fit the stubs and steering arms. (yeh right!) This
will need 14 in wheels in HQ pattern.
3/ Fit HQ to WB stubs
and rotors, grind the calipers and the top control arms, end up with HQ
pattern and suffer alignment and bumpsteer issues.
Fit the calipers to
the rear and they hit the lump in the crossmember on LH/UC.
4/ Keep you standard
disc stub, mount to the rear, and bolt on our 290mm by 28 kit with no
cutting or hitting of anything. Minimum 15 inch wheels needed, same
problems needing 8mm spacer for Simmonds. (You Torana guys seem to love
those Simmonds wheels too!)
5/ Go 17 inch wheel
for a 330 version, and this will still need control arm and lump in
crossmember surgery.
Master Cylinder and
Boosters
1/ FX to FJ
There are a lot of
ways to do this because the original was under the floor.
One way or another you
are going to go to a swinging pedal and that means adapting a pedal box.
Any 1 inch bore master cylinder and booster will be fine with all the
above, whether a HQ tandem master and remote VH40 or a master-vac combo is
up to you. The latter will work better.
2/ FE to EK
The standard 1 inch
single master should be dumped for safety reasons but the clutch master is
right next to the brake master. That’s OK if going Auto trans, but fitting
a tandem master with combined master vac will require relocating the
clutch master across if going hydraulic manual clutch.
A smaller Gemini
booster (push rod lengthened) with an XB master will free up a bit of
room. HQ or XB 1 inch master with remote VH40 is OK too but you will need
larger rear wheel cylinders if not boosted. If going 4 wheel discs and
remote boosters the two of the bloody things will be required.
Your Friendly Engineer
will also ask for a brake fail switch/light, and this must be piped so the
pressure is the same both sides, i.e. before any remote boosters. Of
course all tandem master cylinders require a split system pipe up but
that’s the price you pay for progress.
3/ EJ and EH
Same story as above
but the bonnet hinges don’t allow any decent size master vac on manual
cars. Even auto’s will need a pedal box with brake push rod moved across.
4/ HD and HR
Basically see above
for FE to EK, not much different here.
5/ HK to HG
At last, an easy one.
Use the original
standard booster and tandem master with any HQ/WB brakes or any of our big
brake upgrades, the smaller booster is fine but the bigger V8 one has a
stack of power assist. If fitting rear discs, take the residual valve out
of the rear brakes, it’s under the brass seat at the outlet fitting, use a
self tapper to get the seat out.
6/
HQ to HZ
Basically the same
story as HK, standard master cylinder and booster are fine but on HQ
replace the proportioning valve with an adjustable one if fitting rear
discs, or maybe no valve at all is worth a try first. (The front must lock
before the rear)
On HJ to HZ using the
tin top master, remove the prop valve if fitting 4 wheel discs; fit a HQ
one with no valve so that the brake fail switch will be still be there.
Use an adjustable prop
valve if needed, or a HZ unit for 4 wheel discs will work if you can find
one.
7 WB
Don’t forget that WB
had the plastic reservoir master with angled bolts and inbuilt prop valve.
If yours is a Statesman with 4 wheel discs, then bolt on the front upgrade
and go, the rest is right. If you have a Ute, Van or Tonner, and you want
to run rear discs then fit the Statesman disc type master with its correct
prop valve etc.
HQ to HZ Pedal Boxes
One way around the
disc verses drum pedal box question is to go to a 1.125 bore master
cylinder. And where will I get one of these, you ask?
Well it happens that
68 to 82 Corvette master cylinders are a bolt on, same fittings and all,
and they don’t have to cost any more than a new HQ to HZ one. How’s that?
Torana LC to
UC
All Torana’s came with
firewall mounted Master Vacs boosters and tandem master cylinders, and as
a rule when the big cars got a change in design the Torana’s followed. If
you have been taking notice of the above in the Holden HK to WB section,
the same things apply. In fact Torana’s used the same master cylinder as
the equivalent big cars year to year.
Therefore generally,
standard master cylinders are fine with big brakes, and remove residual
valves and propvalves when going to rear discs.
The XU1 and V8 cars
had the bigger double diaphragm boosters but they are not essential.
Lastly if fitting big brakes to one of the last UC’s that had that metric
15/16 VB master, replace it with a 1 inch VB unit. (P10330 bolts on)
Why always use 1inch
masters? Well that’s to keep the twin piston calipers compatible. All LH
to early UC Torana’s and HQ to WB use 64mm caliper pistons. Twin 43mm
pistons have a nearly identical hydraulic area, matching the big calipers
with existing rear discs or drums and existing master cylinders.
Balancing Front/Rear
brakes
REAR DRUMS
With so many variables
and mixing and matching, it might be necessary to fine tune front/rear
balance. Holden made their basic rear wheel cylinders in a variety of bore
sizes, from 9/16 to 1 inch. 7/8 inch is the standard HQ to WB size and ¾
inch most often used on Torana’s LH to UC.
Fit smaller bores for
less rear brakes and bigger bores for more rear brakes.
This might be more
likely if fitting larger rear drums, 9 inch diffs etc.
In the end you MUST
have a design that locks the front brakes just before the rear. This is to
ensure the car doesn’t spin around if the rears lock first. Don’t use an
adjustable prop valve to attempt to fine tune incorrectly balanced rear
brakes; you want them to do the correct share of the work at low pressures
as well as on hard braking. The real point of a rear prop valve is to
basically make sure that the rear brakes never lock, even with a full
panic effort, so that the car will never spin.
REAR DISCS
It’s not possible to
fiddle with rear caliper bores, so you have to fit rear calipers which
were originally a match to the hydraulic area of the front’s in question.
As the weight distribution of the car and tyre sizes etc are probably
different from the donor car a bit of educated guess work is needed. If
small adjustments are needed then harder or softer brake pads are a way to
adjust brake balance.
As a general rule we
find rear brakes do a smaller percentage of the work, and do not make much
heat even when the fronts are working hard. We even have one customer’s
racecar that can brake so hard the rear tyres come several centimeters off
the road at full effort.
Therefore we don’t
usually fit hard “metal king” type rear pads for street use.
There you go, a lot of
our hard earned knowledge for free.
I think we have
covered most of the important things about Holden Brakes and how to
upgrade them, and if this helps me re having to answer those same
questions over and over on the phone and “net” it will all be worth while!
DRIVE SAFELY – FROM
THE GUYS AT HOPPERS STOPPERS
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