Since we've just had a lively discussion about MK1 S gearbox housings, how about a discussion about identifying S hydro bags.
To start it off you can tell by looking at the top of the unit and measure the distance from the top of the steel body to the top of the rubber spring. In the S bags its about 5/8" below the top. On non S bags the distance is more. About 1"? or more. Not exactly sure as I don't have any standard bags to measure.
Since there are early Blue coded bags circa 65/66, late Silver coded bags 66+, and Pink coded Clubman GT bags 71+ we need some part numbers which are moulded into the top of the rubber spring, part numbers painted on the body of the housing and the ones I have have white plastic tape wrapped around the hoses.
I'm only talking about bags used in OZ built cars, not orange and other colour coded bags from the UK.
OK, over to you now.

Edit: Why is it that you can proof read your post several times and think it's OK and as soon as you post it the first thing you spot is a typo?
RonR

Good info..i didn't even know there were different hydro bags

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Starlet Conversion:
http://www.ausmini.com/forums/viewtopic.php?t=15484

OK, Ron - good to see someone else who has a fetish for hydro bags..........

here's what i have to toss into the ring:

early deluxe - no markings/part numbers
Late Mini Deluxe, Mini K -green band- Part # 21A2008
V. early Cooper S-yellow band- Part # 21A1892 front 21A1893 rear
later Cooper S -blue band- Part # 21A1872 front 21A 1874 rear
Latest Cooper S Mk 11, Clubman GT -silver band- Part # 21A2012 rear 21A2014

Also have (one of) 21A1804, but NFI what car its from, most likely MK1 "S"

Peter
Tip on proof reading- read what you've typed, backwards.

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1967 Cooper S - new front bearings to do.
1965 Cooper S shell - Slow progress. No time or money!
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

excellent - now I just need to get some work done so I can justify running back out to the garage and look at numbers!

thanks guys

AEG163... I tried the backwards reading thing.... wierd, and didn't help with typos

!srebmun ta kool dna egarag eht ot tuo kcab gninnur yfitsuj nac I os enod krow emos teg ot deen tsuj I won - tnellecxe

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did I tell you that I won a trophy?

skssgn wrote:
I tried the backwards reading thing.... wierd, and didn't help with typos

Heh, Heh well that's totally buggered up that theory!

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1967 Cooper S - new front bearings to do.
1965 Cooper S shell - Slow progress. No time or money!
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

Those are the numbers I have too, not sure about the last one!

The stamping can be very feint though often need to really wire brush well!

Graham

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Sir Alec! we are not worthy!

where are the numbers stamped? I'm guessing the 21A1477 moulded into the rubber at the top isn't the number we're looking for - since the S and non-S ones I have are the same, even though rubber in the non S ones is insert further than the S ones... 20mm v's 30mm

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did I tell you that I won a trophy?

Correct. The relevant part #'s are stamped on the metal casing (the "bulge"), but are often hard to detect & you may need a wire brush to remove rust, paint, crud etc to spot them. I think the # is preceeded by year of manufacture eg '67, '71 etc.
As mentioned B4, some early displacers have no number actually stamped into the casing & part #'s were painted on, and obviously long since gone...............

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1967 Cooper S - new front bearings to do.
1965 Cooper S shell - Slow progress. No time or money!
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

A gold medal to the man who mentioned the number stamping on the casing.
Did some checking on some S hydro bags I have.
The original set from my 68 MK1.5 and a pair of front bags from a 2/70 build date MK2.
I replaced the original set about 25-30 years ago when the car started to feel like you were driving a yo-yo. Lesson: never throw anything out.
These were replaced with a Clubman GT set which was all that was available by then. These were Pink coded bags and are still in the car. No difference in ride or handling to the original bags. Part numbers on these were Front AYG4113, Rear AYG7061. From what I remember they had pink bands on the housing and white plastic tape on the front bag hoses, and apart from this appear to be the same as the original Silver coded bags. BMC/Leyland were doing all sorts of number changes around then so maybe they just changed the numbers. Since they are in the car I can't check them.
I found out later that the hydro pump that was used to pump my bags before the replacement was dodgy and was pumping air as well as fluid so it wasn't really necessary to replace them so presumably they are still useable.
Back to the original bags. I cleaned them and lo and behold stamped numbers appeared.
Fronts are stamped 8 21A2012 68. They have the same number stenciled in silver paint and a silver band around the middle of the housing. The rubber bit has the 21A1477 number moulded into it.
Rears are stamped 8 21A2014 68. they have traces of silver paint but no other obvious markings. The rubber bit has the same 21A1477 moulding.
The front MK2 set are much more interesting. They have numbers stamped on them but it appears somebody got the numbers wrong.
They are stamped 284 21A 021 69 and have part of a number stencilled in silver which is 21A201? and no silver band. The last digit is missing and the 1 is very hard to read. But it's the 21A 021 which is very curious. Looks like a mistake was made when the numbers were stamped. They missed the first 2 altogether and left a space as even under a magnifying glass there is no evidence of any number, and then they reversed the 1 & 2.
The MK1.5 8 and the 68 seem to be the day or month and year when the bags were made and the MK2 284 and 69 would appear to be the day and year.
There are no external differences in any of the bags apart from the numbers. The rubber spring parts all start about 5/8' from the top.
The dark blue covered workshop manual (TP832 1971) I have has some info re the car numbers and the hydro bags used along with the change points in the General Data section at the front..
Double Orange to car 1917, Blue to car 3715, silver from car 3716. It includes the Clubman GT in the same column heading as the Cooper S.
Not sure where all this is heading but what the hell.

RonR

Do the numbers on the units match the part numbers in the book?
From my experience the numbers are always different (take gearboxes and camshafts as an example)

I have a set of bags in the shed from my 68 Cooper S, I will check the numbers later. I know that one is a standard bag and the other three are original.

All good info.
Like to add that the fronts had a single band painted around the hydro displacer and also a band about 1/2 thick on the hose. Rears had 2 bands.
I've added photos of the early blue displacers (from 1966 "S") for those who may be interested in that detailed resto. THer 1968 "S" I restored had silver bands and I went to the trouble of faithfully repainting the displacers.

In addition to this thread I'd like to point out that the rear brake drums were also colour coded with a silver band around the drums which were black
Have more photos ot he units if anyone is interested.
Cheers wild_willy
[img][img]http://i60.photobucket.com/albums/h28/wild_willy/Hydro11.jpg[/img]

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