Master cylinders

[dnb]

I am trying to remove the pistons from a couple of numbers brake and clutch master cylinders that have been sitting for years.
It was suggested I soak them in metho than use air pressure to blow them out, that didn't work. I was told not to use a degreaser as this will swell the rubber, making them harder to remove. Any suggestions appreciated.
Also I have some numbers cylinders without pistons etc, also some PBR Holden cylinders that move freely.
Will the PBR internals be the same as the numbers ones? The PBR ones came of an FC
If they can be used it might solve the problem.
Thanks, Darcy

[mcl1959]

All the pistons are the same from FE right through to HR (some slight design changes but they all work), so it is easiest to sacrifice the piston on a good cylinder and use the piston out of a common HR cylinder.
I have found a good way to loosen a piston up and remove it is to use a large size ezy-out, screw it in the back of the piston and then twist & withdraw it.
Generally a cylinder which has gone dry will need to be recoed to get it in working condition again, but you may be lucky enough to hone it and it will be OK. I always get master cylinders recoed as it isn't worth the hassle putting them on then taking them off again if they give trouble.

Ken

[dnb]

Thank's Ken, now I know I can use the other pistons I'll do as you suggested and use an ezy-out. I didn't want to do anything to drastic till I knew I could use the other pistons. I will defiantly go the reco route. I've got an old mate with all the tools so I'll pay him a visit soon.
Thank's again,
 Darcy

[CraigA]

If you don't want to do them yourself then send them here:

http://www.powerbrakes.com.au/Restoinfo.html

They have done a number of bits for me and are reasonable with pricing, fast, and produce a brand new looking high quality result.

[Rabbitoh]

I am trying to remove the pistons from a couple of numbers brake and clutch master cylinders that have been sitting for years.
It was suggested I soak them in metho than use air pressure to blow them out, that didn't work. I was told not to use a degreaser as this will swell the rubber, making them harder to remove. Any suggestions appreciated.
Also I have some numbers cylinders without pistons etc, also some PBR Holden cylinders that move freely.
Will the PBR internals be the same as the numbers ones? The PBR ones came of an FC
If they can be used it might solve the problem.
Thanks, Darcy

I think I've worked this post out- did you mean N(ew) O(ld) S(tock) by including the term "numbers"? (nos. being an abbreviation for numbers)

[mcl1959]

Chris, I don't think it is as clever as what you have worked out (well done on the creative deductive reasoning though).
Genuine master cylinders apart from having the word "BRAKE" or "CLUTCH" raised up on the side, also have the part number in raised numerals - hence the description - a numbers master cylinder.
Replacement master cylinders which also used the tin top and were sold by Motor Spares and the like did not have the raised words and numbers
Genuine tin tops can be identified by the words "USE ONLY DELCO BRAKE FLUID" on the top of the tin, non genuine tins do not have any words stamped around the top.

Hope this helps the few of us who are nuts about this stuff and hasn't bored the rest of you too much

Ken

[mc54]

Since we are on the subject.

I have kept the master cylinders that came with my car with thought of maybe having them reconditioned one day.

The one for the brakes has the word brake and says holden with the part number 742384 and the tin has the writing on the top.
The one for the clutch has the word clutch and says ABS with the part number 412001 and the tin has the writing on the top.
Now that I look closer at them they are a bit different from each other.
Could it be that the clutch master cylinder has been replaced and the tin swapped over.

Mike

[mcl1959]

Yes you could buy the cylinder as a replacement back in the day and screw your old tin on.

Ken

[EffCee]

Ken,

You are an absolute wealth of information as always. I have a pair of tin resorvoir master cylinders, which I thought were genuine, which have brake and clutch marked on the side, but no part numbers, the reservoirs are tin but alas no "use only delco brake fluid" on the top

I am assuming that these were the type that were sold by motor spares

the clutch slave cylinder I have has the part number on the side, so I am assuming that this is am genuine item. Did the genuine wheel cylinders have part numbers or markings on them as well?

Keith

[mcl1959]

Keith, yes the ones you have are not genuine, but only the fussiest of people will notice or even care.
I find that it's not that I try so hard for originality to please others, but to satisfy my own nagging thoughts that I can't live with something that is wrong if I know it is wrong.
I think I could be described as obsessive though

Original wheel cylinders have the word "HOLDEN" cast into the side and are pretty hard to find nowadays since so many have been replaced by the cheaper ones over the years. You can usually find them on a rusty old wreck on a country farm where you think nothing can be any good left on it.  Also look for the original metal brake adjuster hole covers (most people don't know they exist), and the even rarer brake drum retainer clips which sit on the wheel studs and hold the brake drum in place while the wheel is off.

The original clutch slave cylinder is cast iron and is once again hard to find. Later GMH issue replacements are aluminium and aftermarket ones are also aluminium but do not have the word "HOLDEN" on them.

Thanks for the compliment - I am always happy to supply info on originality and modification advice as appropriate.

Ken