76 replies to this topic

[xu2308]

AFAIK the only boosters fitted to XU1s at the factory were the VH317 (up to 7/71) & VH324 (7/71 onwards).

There are other numbers off early HK (relay lever type) which will fit straight in & look the same as XU1 boosters. They are VH300, 304 & 311. The only external differences are the push rod length & vacuum valve hole size.

There are also 305, 320, 329 & 330 off later HK/T/G & LH/LX V8. These look the same again but need the pedal push rod modified to fit LC/LJ.

Over the years, the various brake reconditioners have mixed & matched cases & other hardware when building boosters, so any of the above could turn up on an LC/LJ substituting for an XU1 original.

Dr Terry

All very interesting Dr Terry and Gong

[Dr Terry]

I have not been able to work out why the check valve hole sizes vary, but think the 6cys had the small hole so the air rush didn't kill the motor at idle, and the large hole for the V8, but I am open to suggestions on this? Mike

No, AFAIK it was just a PBR redesign of the vacuum valve.

All of the 1960s boosters, from VH44 onwards had the old style 'fat' valve which needed the larger hole. Around mid 1971 they released a newer design which utilised a smaller diameter grommet. All the boosters from then onwards had the smaller hole. Dattoman ??

Dr Terry

[glenn stanley]

There is the likely hood that your car is an old NSW Police GTR fited with the XU1 options. If the booster bracket hole is in the correct position for the larger booster IE: not futher back so the bracket is not at 90 degrees then you may have a Police GTR. Many of these had the boosters changed over to PBR recos after the originals failed due to the heavy braking loads. There's a number of other parts that are also unique ot Police GTR's. Some were also sold as replacments for write offs and were sold via the closest dealers not through the governement fleet. In 1972 and in true Government style they purchased GTR's as they were $300 less than the XU1's and then they used a separate budget to have the XU1 options fitted at the dealers. The diff ratios were 3.08

[xu2308]

The Car was Sold from Smiths of Geelong in Victoria not from NSW, there a guy at smiths of geelong who worked from the early 1970's to this day, he told me u had the loot back then you could get what u want

[xu2308]

Smiths of Geelong - did they sell Police GTR's with XU-1 Options ?????????????

[dattoman]

You know I've never really paid too much attention to the size of the hole
I just stick the valve in !!

Yes there is probably a date PBR changed to the cheaper to manufacture valve
It wasn't a Holden specification... just a manufacturers production change

[ewe-one]

We only need dates for the 1972 models now and we nearly have the full set of dates,

1970 17 -7 - 70

1971 22 - A - 71 & likely G 1 date

1972 I would expect a Jan 72 date and a G 2 date

1973 likely Jan 73 and 10 G 3 date

Again it seems to come back to Cams minimum numbers by the looks as the first 200 are always required for Homologation and to be eligable to race, then 500 were the minumum numbers, Holden would have know these numbers in advance by reading the CAMS rules.
By mid year except 1970 which the dates started in July each time there is a date change, apart from likely not wanting to carrying stock from January these later minimum numbers may not have been quite so predictable.
1971 300 extras were built then 72 the numbers were the same 300 then in 73 the numbers were changed to 250 so I see that from July the dates changed each time 1971, 1972 and 1973

Mike

Not sure if this helps.
 break_booster.jpg   52.99K   10 downloads
The interesting thing is if '9' is the day and 'J' is the month (Sept) then it seem to have been built on a Saturday. Was working in the weekend the norm in '72? Then again I guess it better than being built a Monday or a Friday.

Cheers

[Kockum]

A well respected forum member had a VH 324 booster for sale a few years ago .

Hard to tell from the photo , cast date was 3 G 2 or 31 G 2 .

[Kockum]

31 G 2 it is .

[crabba67]

My number for the list
Build 6/9/72
VH324 31G2

[Kockum]

Hi Guys.
My first post on this forum so Gday all.
Do not own an XU-1 at the moment but have ( back in the eighties, LC XU-1 ex racecar on road rego) and would like to again.....they're beaut.

For your info,, same topic for Monaros is somewhat confusing. I've attached a pic of the booster presently on my 327 HK Monaro with type two engine (commonly referred to as a type two HK or Series two Monaro). VH312 is yet another number........

I feel that this booster is the right one for the car but am not sure and a little confused as a respected and highly knowledgeable person told me it should have a booster with the larger diameter hole and the blue check valve which I think is the VH300 with the offset pushrod.


Cheers
Nick.

Hello Nick ,

What you have been told is correct -- there is only one check valve [ VS10573 ] and check valve grommet [VS10416 ] listed in the blue HK parts catalogue .

The HT parts catalogue lists two check valves and two check valve grommets .


Valve assembly- check [ blue plastic ] - VS10573 .
Grommet [ blue check valve - VS1O416

Valve assembly- check [WHITE PLASTIC ] - VS11184.
Grommet [white check valve - VS11185 .

As you can see , all HK and some HT vehicles regardless of engine size that left the factory with power boosters have the larger valve and grommet .

[dattoman]

The "offset pushrod" was a cantilever type bracket that I believe was fitted to early cars

[Kockum]

Hello Nick ,

If your car is the one I am thinking it is - Picardy red with black interior that from time to time has a rack at the back of the car with a mini- bike aboard , then it is a very nice 327 .

[Kockum]

Hello Nick ,


Yes I saw your car at Warwick .

I am as keen as mustard to see more photo's of your car .
Incorporating the mini- bike in your display is a nice touch that certainly makes your car stand out from the crowd .

More booster info would be good .
A friend has a relatively early build Pagewood HK 327 ( passenger side alternator ) . Bought from the original owner .
His booster appears to have never had the stainless steel model ID plate spot welded onto it .
Has the large check valve hole and is the direct push rod type .
This booster has a seven digit stencil number that is somewhat faded but still readable that begins with - 74.....
The HK parts catalogue lists R/H drive disc brake direct push rod type booster P/N - 2813781 .