Removing pistons/ recreate tin reservoir brake/clutch master cylinders

[Jolls]

Hi All,

I have the original tin top master cylinders that have been off the car for 15 plus years. One of the cans looks as though it could be usable - the other just a rusted mess. I found a thread here about re-creating the cans - but no description of how they went about it. Does anyone by chance have the detail on how the tins were re-created?

As you can imagine being stored for 15 odd years the pistons are seized inside the master cylinders. I have been bathing them in WD40 for the last few days and it is starting the leak down relatively quicly so it is probably time to start planning on popping the pistons out. My plan is to use grease to force them out. Does anyone know if there is a grease nipple/brass step u thread and grease nipple combo to do the trick? or - si there a better way to accomplish this task? I mean if there is an easier way I'm all for it.

Cheer Craig

[ardiesse]

Craig,

The master cylinders' compensating port will defeat you if you use the grease-gun.  I'd suggest an ezy-out of the right size.  I have (shh) also used a 7/16" or 1/2" UNF tap.  Once it "bites" into the piston's pushrod hole, it's fairly easy to extract the piston.

And to remove the master cylinder reservoirs and caps, preheat oven to just above 100 degrees, put the cylinders in the oven, then remove the caps and reservoirs.  Wear leather gloves.

Rob

[Jolls]

Thanks Rob

Thanks for the advice, your wisdom has saved me from defeat. The tried and true method it is.

[Jolls]

Some success and some failure today.

Success - removed the pistons by cutting a thread and using old bolts to work them out. Pretty simple, but the clutch took a fair bit of force and a couple of taps with a hammer to break the bone initially. It doesn't look as though they were rusted in place - more like the rubber broke down and became a type of glue stuck to the wall of the bore. The bores on both look to be in pretty good condition and we may get away with a hone as opposed to having to resleeve them. Once they have soaked a bit and I have them cleaned up and in good light I can make a better assessmnet. I am hopeful, but not overly so.

Failure - couldn't remove the top from the tin reservoir. It looks to have been in a vice/multis before and the lid and threads are damaged and rusted together.

This creates a bigger dilemma. From my research on this site I think that the plastic and tin reservoirs aren't a match. So I will either need to find good reservoirs (I expect that will be a real challenge), purchase a complete set of brake/clutch master cylinders with reservoirs (expensive) or create a new set. I did read on here about someone making a set up but there were no details. I would be really interested to know what was used to build them so I can have a crack. Otherwise I will simply have to start searching antique shps for tins with threaded lids.

In the interim I can probably purchase a set (brake & clutch) of the plastic reservoir master cylinders and use them until I get around to finding/fixing the originals.

[Dr_Terry]

This creates a bigger dilemma. From my research on this site I think that the plastic and tin reservoirs aren't a match. So I will either need to find good reservoirs (I expect that will be a real challenge), purchase a complete set of brake/clutch master cylinders with reservoirs (expensive) or create a new set. I did read on here about someone making a set up but there were no details. I would be really interested to know what was used to build them so I can have a crack. Otherwise I will simply have to start searching antique shps for tins with threaded lids.

There was an aftermarket plastic reservoir (branded ABS) made back in the day which does fit in place of the tin can type. They have a black lid & you do see them from time to time at swap meets & on ebay.

Dr Terry

[ardiesse]

Craig,

It's time to get serious.  If you have a blowtorch, *gently* heat the lid of the reservoir and see whether you can unscrew it (leather gloves!).  You might have to heat it until it smokes and the rust turns black.  Hopefully you don't have to go cherry-red.

Rob

[Errol62]

As Dr Terry said, there is a plastic reservoir. Be careful though as the thread on the base of the reservoir was changed at some point, and the black lid reservoirs were produced to fit both threads. I did have a bunch of these a couple of years ago but moved them on. Old master cylinders are common at swap meets.


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[Jolls]

Craig,

It's time to get serious.  If you have a blowtorch, *gently* heat the lid of the reservoir and see whether you can unscrew it (leather gloves!).  You might have to heat it until it smokes and the rust turns black.  Hopefully you don't have to go cherry-red.

Rob

I'll get the MAP gas out tomorrow ans see haow we go. What is the worst that can happen?

[Jolls]

As Dr Terry said, there is a plastic reservoir. Be careful though as the thread on the base of the reservoir was changed at some point, and the black lid reservoirs were produced to fit both threads. I did have a bunch of these a couple of years ago but moved them on. Old master cylinders are common at swap meets.


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Thanks for the heads up. I will keep an eye out to see what I can find.

[ardiesse]

The worst that can happen with a MAP gas torch:  everything will fall to bits, because either the cap or the reservoir will have soldered seams . . .

Rob

[Jolls]

The worst that can happen with a MAP gas torch:  everything will fall to bits, because either the cap or the reservoir will have soldered seams . . .

Took it slow and heated it a few times to avoid it falling to bits. Finally got the lid off - stubborn bugger. Now have to find a friend to go with him for the clutch master cylinder!

Thanks for the advice and support.

Cheers n Beers
Craig

[Jolls]

Hi Team

I had not inspected the clutch master cylinder closely as I was more focussed on getting the innards out and the cap off the good tin reservoir that I have. I then turned my attention to what parts I needed to get the brakes back up to speed. I had assumed (big mistake I know) that because I had two tin reservoirs that one was for the brake and the other the clutch and that they were both the same. I was right in that both tins have the same thread on the bottom ( the top half of the second one is rusted away); however, when I went to see if the brake fitted the clutch I found that the reservoir base was way too small for the clutch master cylinder. I'm pretty sure I know the answer I am going to receive but I will ask anyway because I can't find any information in the manuals.

Are the tin reservoirs the same on both the brake and clutch master cylinder? They certaily look that way form the photos I have seen; but then again they are all of complete units.

If they are the same thread then I expect that I have a tin topped brake master cylinder and plastic topped clutch cylinder. Either way I have another parts problem to resolve!

It won't matter to me if they are a mismatch to get us up and running but I will need to make a decision on which way to jump so I can start looking for the matching part(s). Just got to love projects that start with parts in plastic buckets - always a surprise!

I look forward to your wisdom.

Cheers n Beers
Craig

[ardiesse]

Craig,

Original equipment master cylinders helpfully have "brake" or "clutch" cast in relief on the side.  Post the part numbers if you can read them.

Brake and clutch reservoirs interchange if both master cylinders are correct for the model.  But - both the cylinders and the reservoirs were revised by Holden, twice, I think.  EJ, EH and early HD had tall, narrow tin reservoirs.  Late HDs and HRs had plastic reservoirs.  You can't take an HR reservoir and expect it to fit an FE-EK master cylinder, because the threaded part is bigger.  And the later brake master cylinders have slightly wider webbing than the early ones.

So it sounds to me like your clutch master cylinder is the later type, while your brake master cylinder is the early type.

Are (the remains of) your reservoirs both the squat, wide ones?

Rob

[Jolls]

Craig,

Original equipment master cylinders helpfully have "brake" or "clutch" cast in relief on the side.  Post the part numbers if you can read them.

Brake and clutch reservoirs interchange if both master cylinders are correct for the model.  But - both the cylinders and the reservoirs were revised by Holden, twice, I think.  EJ, EH and early HD had tall, narrow tin reservoirs.  Late HDs and HRs had plastic reservoirs.  You can't take an HR reservoir and expect it to fit an FE-EK master cylinder, because the threaded part is bigger.  And the later brake master cylinders have slightly wider webbing than the early ones.

So it sounds to me like your clutch master cylinder is the later type, while your brake master cylinder is the early type.

Are (the remains of) your reservoirs both the squat, wide ones?

Rob

Hi Rob,

Confirmed my suspiscion. Thank you.

The brake master cylinder is is part number is 7423384. I have identified another that looks exactly the same on the net with part number 7409631 - confusing!
The clutch master cylinder is 7426553 232. I found and identical one listed on the web apparently beloning to a HD/HR - white plastic reservoir with white lid. Are you able to let me know the correct part number for the FC clutch master cylinder.

I guess the next question is what clutch slave cylinder do I match it up to? I would assume that anything that fits a grey motor would suffice - but then again.

In relation to the 1 1/2 reserviors I have on hnad both are the short squat tin reservoirs and both fit the brake master cylinder.

Thanks for taking the time to educate me.

Cheers n Beers
Craig

[ardiesse]

742... part numbers are EH/HD vintage.  This is where we need Clay with his master parts catalog.  Mine dates from 1957.  It lists 7409631 as the brake master cylinder, and 7412001 as the clutch master cylinder (body, not assembly).

All master cylinders are 1" bore, and are functionally equivalent (except for check valve in the brake cylinder).

Rob

[Jolls]

742... part numbers are EH/HD vintage.  This is where we need Clay with his master parts catalog.  Mine dates from 1957.  It lists 7409631 as the brake master cylinder, and 7412001 as the clutch master cylinder (body, not assembly).

All master cylinders are 1" bore, and are functionally equivalent (except for check valve in the brake cylinder).

Rob

Hi Rob,

Thanks, I will hunt around and see what I can find. In the interim I may just purchase a set of aftermarket master cylinders and a clutch slave cylinder to get myself up and running. There are plenty about. I can then take my time finding the period correct options and restoring them.

Really appreciate your guidance.

Regards

Craig

[Errol62]

From the MPC
I have just removed my clutch hydraulics to replace with a flash concentric slave and compatible 5/8" master from an XR Ford. All in good working order with an as new hose and slave (Protec) and good original master with the black plastic cap. Would be a partial solution for you, at least. I can put some photos up if you are interested. Would be good to see them used I suppose, as my current build will be auto and I hope I won't be doing another after that.....

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[Errol62]

Now I've taken the photos I see it is an after-market master, but a decent PBR one. Don't buy the new ones, they are absolute rubbish.

I just removed this original one also.

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[Errol62]

I could possibly also supply a matching black cap reservoir for brake. However, would need to verify the thread size. I've a feeling these will be the later ones.

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[Jolls]

Hi Errol,

Thanks so much for your kind offer - sent you a PM.

Cheers n Beers
Jolls