Repair or replace brake master cylinder

Yes Rick, the yellow cad is correct, and mine looked like that after White Post did their work. Here’s how mine looked beforehand, and yes, all of the fluid in the pan came out of it! :slight_smile:

image

RobY

Was it White Post, or Apple?

Not that I need their services, but if ever I do…

Maybe or maybe not. I’ll not state who it was. At least not to the forum at large.

It was years ago and their QC may have improved and/or my experience could have been a fluke. Regardless it soured me on sleeve jobs.

I believe the booster can is correct both silver and yellow cad. The original in my 9-65 car was silver, while one I picked up for parts clearly came originally with the yellow tint. Probably just a minor change at the vendor.

Is that seawater? :grinning:

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Good, I sure don’t want to change it!

Thanks Lee. Karps is still in business. I had thought they had closed down. I’ve contacted them and will give a report when I hear back.
It wasn’t so long ago that car restorers frowned on sleeving brake MCs. I don’t hear any discussion about this anymore. I wonder why.

The vacuum can on my booster on my '68 was silver. I bought the car in 1972 so I’m pretty sure it was original.

As I’m reading through this thread, this fact disturbs me.

FWIW, I restored my car beginning in 1985 using many NOS parts, including brake and clutch cylinders, sleeved brake caliper cylinders, etc. I used dot 5 silicone fluid, and have never had an issue. I’m still on the original parts and fluid 36 years later with zero problems. Yes, I know they say to flush every x years or so, thus I’m a testament to laziness and deferred maintenance. Still, my experience tells me I will never, EVER go back to dot 3 and its inevitably fatal hygroscopic properties.

Just an observation.

I agree completely. I ignored the ‘do not recommend’ and used DOT5 (as I have for the past 20+ years).

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“Fatal”? In the type of fluid used by probably over 1 billion cars that have racked up trillions of miles driven? I’ll take that track record over that of DOT 5.

If glycol-based fluids are changed like they should be, there would be virtually no chance of a fatal issue from the fluid. And given that the vast majority of people never change their glycol based brake fluids during their ownership of a car, there is very little chance of fatal effects even if they don’t.

Since glycol based fluids have demonstrably superior performance in general than silicone, that is why they are used as OEM fill and in racing. For our classics, DOT 5 performs well enough for the vast majority of us, so it’s not an issue.

The benefits may be worth it for some and I’m not throwing rocks at any who likes DOT 5. I just don’t think it’s “fatal” to the owner or the car.

But I would think that owners who pride themselves in maintaining their vehicles would not have a big problem with changing brake fluid every 2 - 3 years (OK, I have to admit if you don’t have a lift and/or rear remote brake bleeders, this can make one wish for a fluid that can be left in for 5+years…)

Dave

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Count me in this here group: blaming lack of maintenance is not a suitable excuse.

Apparently, DoT 5 seems to work fine.

However, the massive amount of data that shows properly-maintained DoT 3 systems can work well is not, IMO, an excuse to completely abandon it.

By “fatal” I meant to the system, not the human driving the car. I apologize, I thought that was clear.

Our E-type systems aren’t modern, but then, you know that, and that’s the subject of this thread: replacement of brake and clutch components due to corrosion from the hygroscopic properties of dot 3 brake fluid.

In 1971, on my four-year-old E-Type, the clutch slave cylinder rusted out. The calipers leaked. It was a mess.

In modern cars, and, indeed, in our E-type restorations, we use sleeved calipers (or non rusting metals) and related components to combat the very well known shortcomings of dot 3 brake fluid. Still, our cars are of 1950s and 60s technology, and these systems are a well known weak link with dot 3.

Agreed, dot 5 is not for racing, but I don’t race my E-Type, which I’ve had for 50 years, the last 35 utilizing dot 5 brake fluid with no issues whatsoever. That’s roughly a nine-fold improvement with no required maintenance on my part. How can this positive result be argued?

Just my two cents, and I understand your opinion is valid too.

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The “massive amount of data” on E-Types is that the system begins to rust out from the first day of ownership (again, the subject of this post). Not so on modern systems where the known bugs have been worked out with non rusting components and hoses that don’t literally suck water out of the air, like on our E-Types.

Interestingly, I’m reading my owners manual and I can find nothing relating to brake and clutch system fluid replacement intervals that would equate to, in hindsight, quite necessary “proper maintenance.” There’s lots about checking the levels and bleeding the system if it gets “spongy,” but nothing about the need to replace the fluid to avoid corrosion of the entire system, which again, happened to me on a four year old car.

It’s why I went to dot 5 in 1986, and I’m not looking back.

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This bottle of silicone fluid is 35 years old, and I’ve never needed it for system replenishment. Note the mileage rating. You can’t make this stuff up.

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You’re missing the point.

In the end, choose what you choose.

What point am I missing? Choose dot 3, and you have a maintenance nightmare with replacement components that will rust internally from day one, just like the discarded OEM parts. I’d be willing to bet that all of us have experienced this in our E-Types because of the old technogy/dot 3 combination, , but not in our modern everyday drivers. (Side note: my 2004/130,000 mile Chrysler Pacifica hasn’t required a brake fluid change. What’s up with that?)

Rebuild the system with dot 5 and your maintenance issues go away. My car is proof of that.

Important note: the system has to be completely rebuilt if you go to dot 5. You can’t just bleed the old fluid out. There are too many nooks and crannies where old fluid will remain. The two fluids are not miscible, and spongy braking will occur, as well as corrosion sludge from the old system will be nudged loose.

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My main emphasis is that I don’t think DOT 3 is a maintenance nightmare. If it were, tens if not hundreds of millions of cars, made before 1970, would be suffering from corroding brake parts and leaks within a few years of purchase.

If for some reason, E-types are particularly vulnerable to this, my bets would be placed on either 1) lack of use somehow accelerating corrosion (not sure if this is possible) or 2) shoddy rubber seals that fail more easily than other manufacturers (more likely.)

Yet, if even E-type brake systems were failing within a few years due to brake system corrosion, then they would be notorious for this kind of failure. It would rank right up there with rusty sills and the Prince Of Darkness, Lucas.

Actually, it would have probably been considered a serious safety hazard, and maybe it, not the Corvair, would have been featured in “Unsafe At Any Speed.” Certainly, it would have justified a NHSTA recall in the United States.

My parents owned cars from the sixties. None ever had brake leaks or corrosion failures, and they never changed the brake fluid in anything they ever owned, and they all used DOT 3. I don’t think it’s a matter of modern design and materials, unless one calls post WW2 “modern.”

Dave

Then how do we explain the need for sleeved calipers and the replacement of rusted out master and slave cylinders after a few years of use? Or even the need for this thread?

I stand by my comments of my four year old car having rusty and leaking brake and clutch components in 1971.

I also know that if I’d been running dot 3 in a rebuilt but unmaintained system for the last 35 years, I’d be faced with the dilemma the OP has at this moment, along with the other commenters here.

Now 20 20 hindsight tells us we need to “properly maintain our E-Type brake and clutch systems” which involves bleeding out the rusty, mucky dot 3 before it destroys the expensive components. Why doesn’t the manual tell us to do this, along with changing the oil and poking the debris out of the door drains on a routine basis? Answer: the engineers didn’t prepare for it.

My business before retirement was hydraulic attachments in heavy construction equipment. I don’t know of a tractor out there from Caterpillar to John Deere to Komatsu that instructs in the manual to flush the hydraulic system during the life of the machine. Hydraulic fluid in tractors is not hygroscopic. Dot 3 in old brake systems is. It works fine in today’s cars that it’s designed to last in, but I think it’s a poor match for old Jaguars.

Once again, just my take on the subject after 50 years of enjoyment, regardless of the problems.

I prefer Dot 4, maybe for the same reason I prefer the original oil filter can and points and condenser. I enjoy working on the car as a hobby, and look at jobs like flushing the brake fluid and the cooling system as an opportunity to get under the car to make sure it’s ready for the next drive. Was it someone on this forum who once said “If it ain’t broke, fix it again”?

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