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MG MGB Technical - Brake Master Cylinders -New vs. Rebuilt

I am contemplating a brake system overhaul on my 69B.
Apple Hydraulics sells a remanufactured unit, sleeved in bronze, for $125.00 I can buy a new one for $152 from
Jeff Zorn at LBC.
Given the spotty reputation that some new parts have, is there an advantage to an older unit sleeved, and is the sleeve longer lasting than the original bore, or are new Lockheed parts still pretty good?
Andrew Blackley

Andrew. I have used new Lockeed master cylinders on my 68 GT and my daughter's 77 B within the last year or so with no problems. To the best of my knowledge, Apple has an excellent reputation for the quality of their rebuilt master cylinders. I would suggest you do what your are most comfortable with. Les
Les Bengtson

I rebuilt my complete brake system a couple of years ago and bought a rebuild kit for the master cylinder, figured it would be a good way to save some cash..it ended up to be quite a bit..If you feel up to the task and have the abilities I would look at going that route. The rebuild is quite simple and only took an hour or so to complete. Just watch for any deep pitting in the bore, the surface stuff you can clean out with brake fluid, a hose or some very fine emery paper. I think that the rebuild kit cost about 30 bucks or so
EJW Willis

Gentleman;
That cylinder 68-74 is one of the more difucult to rebuild. I have done many through the years but they are getting so old that new makes a lot of sense. Then get in the habit of fresh fluid once a year and it will out last you! Bob
Bob Thompson

Andrew-
We put a new Lockheed master cylinder into #4 Son's 1973 Roadster when his old one proved to be too far gone to be rebuilt again. So far it's worked like a charm with no leakage whatsoever. Like you, I often bemoan the decline in quality of some of our replacement parts, but at least Lockheed is one manufacturer that hasn't compromised on quality.
Steve S.

Andrew,
One extra point concerning the re sleeving, if you decide to go that way, is to see if it is available in stainless steel rather than bronze.Cheers, Pete
Peter Thomas

I agree with Peter from Queensland and have used many cylinders resleeved with stainless. In reality the bore is better than a new cylinder. The neagative is how rusty the assembly is to start with.
However with my recent total car rebuild I had a disaster. The resleeved cylinder had a fault where the reservoir is soldered on to the cylinder. The assembly had been replated and apparently this weakened the solder. This leaked unnoticed onto my new 2 pack engine bay paint job. I then spat the dummy and bought 2 new cylinders.
I would still use resleeved cylinders, but I would want to inspect the cylinder I was having done before and after the job.
Ian Buckley

Do you have to get all the nasty rust from the surface of the internal bore, prior to rebuilding.

Someone mentioned to me using a set of stones down the bore connected to an electric drill, and giving them a wizz.

Will this be successful on a 1980 dual MC.
Alex

I think what is being referred to is a honing tool.

Has anyone used such a tool and obtained good results.

Answers on a scale of 1-10 would be a helpful guide.
Tom

I haven't used one on a 'B master cylinder, but years ago (many, many years)I routinely honed master and wheel cylinders during rebuilds. I wouldn't do it if the bore is pitted, but it should be fine to remove any build-up of crud.
Joe Reed

Personally I find fine (>600) wet and dry, used round my finger or a stick of wood (cut a slot) with brake fluid does the job fine (pause for the howls of protest by the purists). Good engineering practice would not condone this but I have rarely found a cylinder so bad that this would not fix it. All it really does is remove the crud. Obviously if the cylinder was ridged this would not be a good idea but then again I doubt if a hone would suffice under these cicumstances either. I have tried hones and they are difficult to control, especially on single ended(single piston) cylinders. They also have a tendency to catch on any slots in the cylinder, for handbrake linkages and the like, with consequent damage to the stones. It goes without saying that _all_ grit must be removed, but the same goes for a hone.
ian thomson

Alex,
The honing tool you referred to is something of the proverbial two edged sword.

It is quick BUT it does give the best results with some practice which may not be what you want to hear if this is a one-off item or the first time you have done this.

Honing tools are "universal" in that the hones move outward under centrifugal force to whatever size bore is being reground and grind away the material to leave a smooth finish. A lubricant is ued to keep temperatures down, reduce the rate of cutting and allow the hones to "float"
******************************************************
Tom,
A good operator can salvage a severly pitted cylinder but a lousy operator can ruin a good one.

On a scale of ten: 9 for speed. ?? for quality of finiah since so much depends on the skill of the user.

Ian's comments are very accurate and his method would be my choice too. Go slow and check often and the method Ian suggests will provide a result as good as any.
Peter Thomas

This thread was discussed between 09/05/2002 and 16/05/2002

MG MGB Technical index

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