Wednesday, March 5, 2014

Rebuilding Brakes on Vintage and Collector Cars

The last of the Crewe-built Bentleys
Rebuilding a rear brake caliper on a vintage Rolls Royce 

Brake jobs used to be so simple!  Pop a set of pads into the calipers, and you were good to go.  No more, especially on high end cars like this Rolls.  Let’s look at what goes into a quality brake job on a classic high end car like this, using a 1980s Rolls Royce as an example.

When a car is new, everything moves freely and it’s easy to do routine service.  For the first service you can often still do pads only, but it gets more complex from there.  By the second pad change the car is certainly ready for new rotors.  When do you need rotors?

There are three reasons you may need new rotors:
1 – They are worn below the minimum safe limit, as marked on the rotor
2 – The rotors are out of true, and the car shudders when stopping
3 – The rotors are glazed with rust, so braking effectiveness is lost

Here is an example of a brake rotor showing both wear (1) and rust glazing (3)  This deterioration is all on the inside. The other side - facing the wheel - looked remarkably good.  Don't be fooled.

Rust on a brake rotor makes it slippery

When working on vintage cars 2 and 3 are common, but you see cars with 1,2, and 3 all together.  Rarely do you see (1) by itself. 

Measuring a brake rotor to see if it's too thin.  The numbers tell the story.
On most mass produced cars the rotors pop off with a few minutes work.  Not so on a Crewe-built (pre-1999) Rolls Royce or Bentley.  To get the front rotors off you are looking at a few hours work to remove the two calipers off each side, then the pipes and then the hub.  Once the hub is off the rotor itself can be removed with the whole thing clamped in a vise.

Separating brake rotor from hub - Rolls Royce Shadow
The rear hubs are a much more complex affair.  You need a special RR/B hydraulic puller to get the rear hubs apart, and to get them off the car.  Once they are on the ground the disassembly requires a press and various accessories.

Don’t be surprised if you find years or decades of neglect when you pull rear hubs.  Totally rotted rotors, and ruined bearings and races are common because some less-service-oriented people put difficult jobs off till “later” and later never comes.

On a newer car you’d just pop a rotor on at this point, but these Crewe RR products are old enough that shortcuts will come back and bite you.  We suggest removing and examining the wheel bearings, and replacing them if they are anything less than flawless.  In most cases, they are at the ends of their lives.  Don’t forget to do the seals.

Worn out wheel bearings and seals
We pack hubs with modern synthetic grease; all the hub rebuilding is done off the car on the bench.  Otherwise the process of bearing service is much the same as thirty years ago.  We use drifts to knock out the old races, and a press to set the new ones in place.

Rebuilt rear hub ready to install
We suggest splitting and rebuilding the calipers on any Rolls Royce that is more than fifteen years old because leakage is common when they get past that age.  And when one leaks, they are all ready.



Rebuilding brake calipers

When the calipers are apart consider refinishing the caliper bodies using the new hi-temp powder or ceramic finishes.  That’s what they do on newer high end cars and it’s a very attractive touch

Rebuilt hub, new rotor, and rebuilt and refinished brake calipers
If your hoses are more than 10 years old you should replace them.  Hoses rot from inside and old ones may blow with no warning.  

New brake hoses
Most owners of collector cars have paid for more than one brake job on modern luxury cars.  How does work like this compare, in terms of cost and time?  The short answer is . . . expect way more of both.

When you do brakes on a modern car the only parts are the pads, rotors, and ancillaries like anti-rattle clips.  On a vintage car the job may include bearings, seals, hoses, caliper parts, and even new hardware.  In addition, hard to get classic parts may be more expensive.  Finally, there may be quality problems.  You can be sure of getting quality brake parts for a late model Mercedes or BMW simply by going to the dealer.  For an old car that may not be an option, and the mail-order stuff can range in quality from wonderful to total junk.  

In general, you get what you pay for.  Here's my rule of thumb:  If you have to choose between five versions of a part (like brake pads) from known reputable vendors and the prices vary widely, the quality will vary just as widely.  You are a lot less likely to get burned buying the top priced part than the bottom priced one.  When prices for the same part range from $29 to $199 the $29 part is usually junk, and the $199 part is probably topnotch.  I know that's not what some people want to hear, but in my experience it's true.

When you fit low quality parts you are asking to do the job over, sometimes with additional damage.

The time to perform the additional steps I outline above can add up too.  Pulling and assembling the rear hubs on a 1970s Rolls Royce or Bentley is a solid two days of work.  And teardown can expose unknown problems, which may need dealing with now.  Rebuilding front hubs is more than a day's job.  Rebuilding the calipers will be another day and a half, plus the time and expense of refinishing the caliper bodies if you decide to do that.  

Rust and corrosion can double those times on cars that have run on salty winter roads.  On a classic car where parts are scarce you may spend days getting corroded stuff apart without damage because it's simply not replaceable at any reasonable cost.

And here's one more thought to consider:  Most people who service late model cars know the owners have limited ownership horizons. They will not own the car they' re fixing today in 1 year or 2 or 5.  Things that may wear out "later" will be someone else's problem.  Not so on the collector car your dad purchased and your son now dreams of owning, when you are old.  For that person, service must be done to a high standard, with a view toward a far distant horizon.

I hope this makes clear some of the additional challenges we face when doing a seemingly common service on an older car.  


John Elder Robison is the general manager of J E Robison Service Company, independent restoration and repair specialists in Springfield, Massachusetts.  John is a longtime technical consultant to the Mercedes, BMW, Porsche and Rolls Royce Owner's Clubs, and he’s owned and restored many of these fine vehicles.  Find him online at www.robisonservice.com or in the real world at 413-785-1665


3 comments:

Tim Parnell said...

Great article. I agree that a more complex repair should be done right the first time; its not the time to go cheap.

Tim Parnell said...

Great article. I agree that a more complex repair should be done right the first time; its not the time to go cheap.

David Williams - Bulkeley said...

...not much hope for selling a shadow