Friday, November 28, 2014

Index to Rolls Royce and Bentley tech tips

Bentley Arnage - (c) J E Robison Service

A rare Rolls Royce Corniche S - (c) J E Robison Service

I've written quite a few articles on Rolls Royce and Bentley, and I have begun gathering them together here.  One day I'll probably turn them into a book.  Till then . . . Feel free to comment or offer corrections.


Thoughts on buying a used Rolls Royce or Bentley - applies to Silver Cloud and newer series cars

More thoughts on Spur - Spirit - Turbo era car buying

Thoughts on restoration - applies to all cars

Evolution of the RR/B models - Silver Shadow through Arnage/Seraph - original article from the Robison Service website

Inspecting a Rolls Royce or Bentley - Applies to Corniche, Continental, Azure, Turbo R, Mulsanne, Eight, Turbo R, Silver Spur, Silver Dawn, Silver Spirit

More Things to Look For in a 1981-2000 Rolls Royce or Bentley - this is the original article from the Robison Service website

The last Crewe built Rolls Royce convertibles - applies to 2000-2002 final Series Corniche

Repairing convertible top hydraulics - Applies to 1996-2004 Rolls Royce and Bentley Corniche and Azure cars

Head gasket failures in Bentley Turbo cars - applies to Turbo R, Continental R and T, Azure, Arnage

Checking engines after head gasket failure - Applies to all cars

Checking and inspecting Rolls Royce hydraulic systems - all cars after Silver Cloud and print to Silver Seraph. Applies to all Shadow/Spur era vehicles

Case Study - brake failure in a Shadow - Silver Shadow era cars with RR363

Rear suspension gas springs - Applies to all 1981 - 1999 cars prior to Silver Seraph

Changing batteries in seat and ECUs, Applies to 1980s-1990s Silver Spirit / Silver Spur / Mulsanne /Eight / Turbo R

Changing alarm ECU batteries,  Applies to 1980s-1990s Silver Spirit / Silver Spur / Mulsanne /Eight / Turbo R

Servicing Shadow and Spur series brakes - applies to 1966 - 1999 cars after Silver Cloud and prior to Silver Seraph

Alcon racing brakes for Continental and Azure - Applies to all 1990s cars but most particularly to the final series Azure, which had these brakes fitted at the factory - a unique variant

Fixing Power Steering Leaks - applies to 90s cars with the reservoir above the alternator

Questions and answers on collector car storage - Applies to all cars

Evaluating paint - Applies to all cars

I hope you find these suggestions useful, and I wish you luck and success, keeping your Rolls Royce or Bentley motorcar on the road!

Best wishes

John Elder Robison

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 RROC and other car clubs, and he’s owned and restored many fine vehicles.  Find him online at www.robisonservice.com or in the real world at 413-785-1665

Wednesday, November 26, 2014

Convertible Top Repair in Bentley Azure / Rolls Royce Corniche

Convertible top hydraulics are shaping up as a major weakness in the Bentley Azure and Final Series Corniche from Rolls Royce.  These cars were built from 1996-2004 (a newer Bentley variant remains in production today) and all are vulnerable to this issue.

The Bentley Azure and RR Cornice are fine cars but the tops are a weakness (c) J E Robison
Here’s the problem, in a nutshell.

The engineers at Crewe wanted to design a fully automatic convertible top for the new Azure series.  But they did not have the resources to do a new design; they had to adapt something else that was already out there.  The Mercedes SL500-type design was well regarded, and they chose to adapt it to the Azure body.

Unfortunately, the design didn’t work as well on the RR/B.  It’s remarkably reliable on the Mercedes, and astonishingly flimsy and incredibly costly to fix on the Azure.  What went wrong?

There are a few essential problems.  First, the systems use very high hydraulic pressures.  Older automatic tops used big cylinders and rams.  With several square inches of ram, you don’t need very high hydraulic pressures to generate the force to move the top.  However, the newer cars use tiny actuators hidden in the top. They are smaller, so the hydraulic pressure needed for a given actuation force rises.  Because the hydraulics are hidden, they are often at a mechanical disadvantage (leverage in reverse) and need to push harder to move the top.

The result:  hydraulic pressures on a 2001 Bentley convertible top can run almost 10 times as high as the pressures on a 1987 Bentley convertible top.  With that factoid in mind, it should not surprise you that the newer tops are not as reliable.

In addition, the newer tops use automatic latches instead of human power to pull it shut and locked.  Those latches are not as rugged as they should be.  Why, you ask?  Look at a Bentley Azure and then look at an SL500.  What do you see?  The Bentley top is significantly larger.  That multiplies the forces on every component and it’s one more reason a reliable Mercedes design didn’t work out the same on the RR/B.

The next problem probably started in Crewe’s engineering department, though I doubt they would admit it.  Mercedes uses plastic lines that are impervious to hydraulic fluid, but that material selection did not translate to RR/B. Someone there chose a hose material that deteriorated with contact with hydraulic fluid.  The result – when they get to be ten years old you see the black rubber casings falling off the hoses, and blowouts inevitably follow. 

How do you check your convertible top hoses?  Look at the hoses in the main hinge area when the top is partly lowered.  Here are examples of hoses that are coming apart.


The upper photo is a closeup of jacketing peeling from a hydraulic hose.  Failure is imminent (c) J E Robison Service
If this problem is ignored you will see leakage, as evidenced by the leaked oil in these photos.

Leaked hydraulic oil in the convertible top well (c) J E Robison Service
Oil seeping from the convertible top hydraulic line bundle 
If you ignore it even longer, you will eventually be showered with oil when a line blows under pressure and the interior of the car is sprayed and damaged.

Header bar line with deterioration.  These are the worst if they blow
"Green showers" most often come from the header bar, when the lines above the rear view mirror blow out.  The reason those lines are the first to blow is that area takes the most beating from the sun. In a hot climate that area can be over 200 degrees all day, and the oil they originally used breaks down into a green jelly that won't pump, and causes pressure surge and blowouts.  Jaguar is known for having this problem too.

The new hydraulic oils are synthetic and they resist this, but the moral there is - change your top hydraulic fluid every few years, or else.

When the top is partly folded there is another thing you want to check – the cables.  These new automatic tops need to fold into a tight space to be hidden under the rear deck.  To do that they rely on cables sewn into the top lining.  Loops of wire around those cables pull the top fabric against the bows and fold everything properly.  If the cables break the top will jam in the bows, and if the bows bend as a result – you have big trouble.

Broken stay cable on Bentley convertible top
In most of these cars you will see leakage from the hydraulic actuators in addition to problems with the lines.  Here is a set of actuators removed for service.  We rebuild these units rather than replace them.



So how do you fix this?  You remove the trunk lining, and the pump and lines.  Open the convertible top boot and remove the top as an assembly. Remove the cover in the convertible top well, and unthread the lines there.  Remove the rear seat, both side panels, the right side floor covering, and the right side dash and windshield pillar trim.  Remove the windshield header bar covers.  Remove the lines and remaining actuators.  Replace and reassemble.

Sounds easy?  Look for a job time of 60-90 hours, more if you are not experienced or run into trouble.

In the next convertible top installment I will begin to cover the actual repair process.


This article is about the automatic convertible top system used in Rolls Royce and Bentley Azure and Corniche from 1996-2005.  Check out this article for thoughts on the newer Bentley GTC convertible top and its problems

And here's an article on 1997-2005 Jaguar XK8 and XKR convertible tops - they have some of the same issues but are simpler to fix


Good luck
John Elder Robison

Robison Service has provided independent service, repair, and restoration for Rolls Royce -Bentley owners all over New England for over 25 years. Founder John Robison is a long time technical consultant for the Rolls Royce and Bentley Owners Club. Our company is an authorized Bosch Car Service Center. We also service Mercedes, Jaguar, Land Rover, Porsche, and MINI motorcars. We have flatbed transport throughout the northeast region, and we work with Intercity and other transporters for greater distances. We also offer pickup and delivery for cars in  Springfield, Wilbraham, Longmeadow, Agawam, Westfield, Northampton, and Amherst.  Our drivers are available to pick up cars in Boston, Hartford, Greenwich/southern CT, New York, Rhode Island, Vermont and New Hampshire.


Checking an engine after head gasket failure


Engines can have head gasket failure in two ways:
  • They can leak oil or coolant onto the ground, with no internal failure
  • The fire ring seal can fail, allowing combustion gases to pressurize the cooling system

Of those two failures the second is by far the worst because it’s usually associated with overheating and sometimes catastrophic engine failure.  The common dealership repair is usually to slap a new head gasket in place and send it down the road.  That works for some engines.  But on others, the result is a repeat failure – a month, a year, or three years later. 

A blown head gasket. Area in the red box is the coolant passage.  The half circle is the combustion seal 
Most of the cars we see are in this latter category.  For example, we get quite a few Land Rover engines that have a “history of head gasket replacements.”  No engine should have repeat head gasket failures.  When that happens, some repair step is being skipped, or there’s another root cause. 

Almost every engine we see needs some additional machine work when the heads come off.  That makes me wonder if the shops who are just slapping in a new gasket are ignoring that and trusting luck, or if we just see the “repeat offenders” because we are more a shop of last resort when the local mechanic could not fix the car.

How can you tell if a gasket alone will fix your problem?  You measure.  Read on, and I’ll show you how we check for problems and what we do when we find them. 

The first things we do are tank clean the head, and then blast it with walnut shell grit to get it as clean as new. Next we measure the head for flatness with a straight edge.  When aluminum heads are removed from an engine, they are usually slightly out of flat.  In addition, they can be corroded.  Sometimes we see damage from coolant gone bad, and we occasionally have to weld that up.  We also see cracks on some engines.  Cracks are typically repaired by welding too.  When all that is done, the surface of the head is machined flat.  If the engine is a V6, V8, or V12 we surface both left and right heads equally so as not to cause a compression imbalance.


Repaired cylinder heads for a Bentley (c) J E Robison Service

If an engine has more than 75,000 miles the heads will always benefit from freshening up.  In that, we reseat the valves, check the guides and fit new seals, and clean the ports. We check for valve seat damage, which will lead to burnt valves.

A burnt valve as seen in the head (c) J E Robison Service
Burnt valve removed from the head (c) J E Robison Service
If the owner wants his engine blueprinted we will also measure each combustion chamber’s volume and increase the size of small chambers to match the volume of the largest chamber.  This is typically done by grinding material away and by recessing the valves deeper into the seats.

The heads are the easy part.  Now we check the block.  We use a straightedge to measure the deck surface for flatness.  Sometimes we find broad warping, while other times we find depressions or valleys.  The head gasket can take up a few thousandths of warp, but a block with 5 or 10 thousandths has to be taken apart and repaired.  The reason:  major warpage of the deck often means the bearing journals are warped too, and if that is ignored the engine will have a lower end failure at some point.

Significant deck warping is a sign of major overheating. 

Illustration of a low spot in an aluminum block deck (c) J E Robison Service
The next thing we look for is out-of-round in the cylinders.  We measure the cylinder bore front to back, and inside to outside.  The difference between those measurements is called “egging.”  We don’t want to see more than .002 inch.  More than that and the piston rings won’t seal well, and the engine will use oil and possibly lose compression.  Egging is another sign of overheating.

We also make those measurements at the top and bottom of the cylinder.  Again we don’t want to see more than .002 difference.  Top to bottom difference is called “taper.”  When a motor has too much taper it may know, and that’s a sign it’s worn out.




Measuring cylinders for taper and egging, BMW V8 shown (c) J E Robison Service
Finally, we test the studs or the head bolt threads, particularly on aluminum engines.  We look for evidence of stripped or pulled threads, and we repair any damaged ones with inserts. An insert repair will be stronger than the original in most cases.





Repairing damaged head studs with oversize inserts Bentley V8 shown (c) J E Robison Service
If the block is out of spec in those areas it should be removed and overhauled.  We can fix dimensional errors like that in most cases.  The other thing we look for is corrosion damage.

If you think this sounds like a lot of work compared to slapping in head gaskets, you are right.  The gasket slap is a strategy for dealerships working on factory warranty (where it just has to last to the end of warranty . . .) and new cars (where corrosion and wear are seldom issues)  If you work on older vehicles, or if you want your repairs to be at least as good as original (as opposed to almost as good as original) this is the only path to take.


Quality engine work takes time, and costs money.  Jobs done correctly last, and the price is soon forgotten while poor quality never goes away.  


If you're wondering what's below the heads, read this story about liner failures in Land Rover V8's and how we fix them.

Good luck
John Elder Robison

Robison Service has provided independent service, repair, and restoration for BMW, Land Rover, Jaguar, Mercedes and Rolls Royce -Bentley owners all over New England for over 25 years. Founder John Robison is a long time technical consultant for the Rolls Royce and Bentley Owners Club. Our company is an authorized Bosch Car Service Center. We also service Mercedes, Jaguar, Land Rover, Porsche, and MINI motorcars. We have flatbed transport throughout the northeast region, and we work with Intercity and other transporters for greater distances. We also offer pickup and delivery for cars in  Springfield, Wilbraham, Longmeadow, Agawam, Westfield, Northampton, and Amherst.

Monday, November 10, 2014

Buying a Used Rolls Royce or Bentley

Many of the people who join the Rolls Royce or Bentley owner’s clubs come to this blog and the club forum with a dream of owning a Rolls Royce or Bentley.  Some already own one, or several.  Some remember a car from childhood, and imagine having a similar car of their own.  Maybe Dad had one, or perhaps an uncle or family friend.  Maybe you just saw them gliding by in New York and want one now that you are older . . .

My son Jack and I at an event, when these now-vintage cars were new (c) J E Robison Service

An early 1980s Rolls Royce Corniche on the show field

That is the thing about these cars . . . they are “the stuff of dreams” for many people, and they stand for a now-vanished era for others.  They are also one of the only symbols of that “lifestyle of the rich and famous” that ever becomes affordable to the average person.  Mansions don’t sell for pennies unless they are in the midst of urban blight, and require helicopter gunships for defense. Big yachts can get inexpensive to buy, but they usually need a million dollars in repairs when they reach that point.  And there is the other thing – neglected boats sink.

Rolls Royce and Bentley cars are different.  They start out at several hundred of today’s dollars, but good 20-year-old examples are often sold for 10% of the new value.  Maintenance on these cars can be steep, but it’s still within the means of many enthusiasts.  And most of the costs are for labor, so a person who does his own work has a major advantage.

As a car club, we should encourage those people, whatever their reason is for being interested in the car.  Ideally, we would do what we can to help them realize their dream in a good way, and not as a nightmare.

The best way to avoid a bad experience is to buy a good car.  If someone comes to the club forum with a car, that die is cast.  All we can do is give our best advice to get the most from whatever car they have.  If they do not have a car, we can offer advice on how to select a good vehicle.  We can steer them toward experts the club membership recognizes as qualified and suggest they inspect any potential acquisition carefully.

And we can encourage them to join the club, which anyone can do at this link.

Finally, we can offer some practical advice.  Here are a few of my thoughts.  Some of you may have different opinions. My perspective is that of a Rolls Royce/Bentley service manager though I have also been a RR/B owner for 20-some years and I too “got the dream” when my grandfather showed me a Silver Cloud, back in the 1960s.

Rolls Royce Silver Cloud II (c) J E Robison Service

RR/B changed corporate ownership in 2003, and almost all the vehicle technology changed on or around that date.  Since then, the majority of dealership service staff has turned over too. That means the service personnel in the dealer network can support post-2003 cars, but many dealers can't support the older vehicles because they lack staff that know the cars. And RR/B is not offering service training on the older vehicles anymore.  For all practical purposes, the “old” Rolls Royce Motors is gone.  For that reason you need to take a lot more care buying an older car, and you need to be sure you have someone to support it. 

As drivers of any kind of car, we get used to "bring it to the dealer" as a last resort.  Whether you drive a Chevrolet, a Toyota, or a Mercedes for your daily beast, that option is always there when your local mechanic is in over his head. Unfortunately that won't work in most places for a 1988 Rolls Royce.

That’s why – if you live in an area where Rolls Royce cars are rare – it’s important to figure out who will care for the car before it needs service.   But what if you want a newer car?

That is where the current dealer networks shine.  Corporate parents BMW and VW have made it easy to buy late model cars with sales incentives and extended warranty just like any other car (the old Rolls Royce never had those things!)  Also, the prevalence of new car lease programs ensures there is a steady supply of 3-6 year old used cars in the dealer network.  If you can afford the purchase price and the annual upkeep ($10k++ per year for service, taxes, fuel, etc.) this is an easy route to take.

Most people who come to this blog or the club forum, though, want older vehicles for a variety of reasons.  So what’s the lowdown on buying an older car?

There are several distinct series of vehicles:
  • The Rolls Royce Seraph/Bentley Arnage series was introduced in 1999 and built through the corporate transition.  These are fine cars but support for them may evaporate as they age. 
  • The Silver Spur/Bentley Turbo and Mulsanne series was made from 1981 to 1999.  These are the most common used RR/B cars in the market.  Good examples – depending on age – sell for $25-40,000 today.
  • The Silver Shadow series was built from 1966-1980 and is also common.  These were fine cars when new but most of the examples in the used car marketplace are in very rough shape.  Costs to make the cars safe to drive often exceed cash value.  Good examples – rare as they are – are excellent driving vehicles and possessed of a more classic style than the newer series.
  • The Bentley Azure/final Corniche cars were made from 1996 through the transition, and are popular because of their price and look.  Good examples are often sold in the $70-100,000 range.  Be careful though – hydraulic problems in the tops are common, and repair can run $20,000.  Tops themselves are costly as well.
  • The Corniche convertibles were made from the 1960s through 1995.  The older convertible cars are the vehicles with the most potential to rise in value over the next decade.  They are the most expensive to buy, but service costs tend to be similar to the others cars and there is more potential for positive return
  • You will also see the occasional Camargue coupe offered for sale. These cars are rare, and have some potential for appreciation, but they have never been really popular.

Once you have settled on a series, the next step is fining a good car.  That’s often a real challenge.  There are lots of rough cars on the market, and it’s easy to be misled because a beautiful exterior can conceal a ton of mechanical neglect.  And a car with cosmetic problems can fool you when the cosmetic repairs turn out vastly more expensive than you anticipated.

Many – indeed most – of the pre-2003 Rolls Royce and Bentley cars that are offered for sale, are offered because they have problems the present owner does not want to address.  They may not say that to you – they may deny it vehemently – but it is true.  Why else would the car be offered for sale?

The worst cars – when it comes to condition – seem to be those on ebay with carfax reports showing 8-10-15 owners.  When you see that kind of ownership profile you have to be vary careful.  Most often, it’s a car that’s been passed from one short-term owner to the next with the condition sliding a little more each transfer.  Cars like that can be horrors.  Be really careful looking at any car like this.  Always ask for service records and owner history.

Talk to the owner and ask yourself if you would want to take over a car that person has cared for.  But know that's a hard call to make. I cannot tell you how many motorists have come to our company and boasted of the loving care they have given to a car that is obviously seriously neglected. All I can say is, their idea of care is different from mine.  Yet there are other owners whose love for machinery show and those are the ones to buy from, if you can find such a person.

Where to find a good car? I know what you are thinking – death, divorce, things like that.  Those things happen, but if the car is really great, there is someone in the wings to take it.  Most of the time.  Incredible deals do pop up, but it’s rare.  When a dealer has the car you have an additional problem because there is now a middleman in the equation who has added to the price and detracted from the available first person knowledge of the vehicle.  The usual dealer advantages – warranty and the backing of a good service department – don’t generally apply to those who sell vintage RR/B cars.

The exception to that - and another seller to seek out -  is the qualified service person who is selling a client's car. For example, John Palma is a recognized Rolls Royce expert in New Jersey. I would not hesitate to buy a car he was selling on behalf of a service client because I'd know he knows what is being offered and I'd presume he could answer my questions. Albers in Zionsville, Indiana is another such organization. Buying from a reputable seller like that will not make the car trouble free, but it will at least be truthfully described and not butchered by hack repairmen.

When a car is sold by someone who’s become unable to drive, or sold out of an estate, it has often been neglected for years.  The finest gentleman in the world can still sell a very rough car, if it’s sat in his summer home garage untouched for 20 years.  There are some wealthy people with a lot of cars who just let them sit.  Those cars can be really nice cosmetically, but need everything when you start driving them.  Of course, if you want the car to sit and admire in your home, that may be a perfect fit for you.

The fact is, any car you buy is going to need work if you want to use it regularly and expect it to be properly functional.  I advise anyone who buys a 1980-1999 Rolls or Bentley to be prepared to put $10,000 into it shortly after purchase, maybe $20,000, and don’t be surprised if it takes more.  If it will strain your budget to spend that money, don’t buy the car in the first place because that is the price of entry most times.

Paying more for a better car will get you a better car, but it will still need work.  That is how these cars are.

You may think of buying a 1965-1980 Shadow-era car.  Those cars may cost less, but they are often run down, and you may double the initial service investment. And I should point out, it’s not an investment in a financial sense.  If you buy a car for $15,000 and put $10,000 into it, it’s still a $15,000 car.  It’s just in better condition and fit for use, where it was not before.  And a Shadow of that vintage can soak up all that mechanical upkeep money while still needing paint, wood, leather.  All that will costs tens of thousands to make right in any Rolls.

The Shadow series cars are great drivers, they look good, and they are the first series of RR/B to be capable of modern highway driving (when they are in good shape)

The older Cloud cars may take less upkeep (but they may also need far more) and they are more valuable.  But they drive like antiques.  If you want a vintage Rolls and know how they drive, go for it.  But don’t expect a 1958 Cloud to drive anything like a modern car.

Cloud era cars are a lot more variable.  Common examples (like the early 50s Bentley) can be cheap to buy and relatively inexpensive to keep on the road.  Really desirable examples – the rare dropheads – are fetching mid-six-figure prices.  So you need to know what you are looking at there.

Older cars (pre-World War II) are even more specialized, and I’d encourage you to learn what you are getting into before buying your first car of this era.  They are nothing like modern vehicles, but they can be a lot of fun.

Before you buy a car, consider who will work on it for you.  The biggest mistake some new owners make is choosing a “service provider” who is not qualified to work on the cars.  All too many mechanics say “sure I can work on those” when in fact they will cause more problems than they fix.  But there are some truly outstanding technicians working the field, and you may be lucky enough to live 10 miles from one.  The best advice there is to ask the members and see where others near you go for service.

I’ve written some more specific advice about what to look for on modern cars, which you can find at this blog  and my website ( www.robisonservice.com ) under service > Rolls Royce/Bentley > advice

Good luck

John Elder Robison

Robison Service has provided independent service, repair, and restoration for Rolls Royce and Bentley owners all over New England for over 25 years. Founder John Robison is a long time technical consultant for the Rolls Royce and Bentley Owners Club. Our company is an authorized Bosch Car Service Center. We also service Mercedes, Jaguar, Land Rover, Porsche, and MINI motorcars. We have flatbed transport throughout the northeast region, and we work with Intercity and other transporters for greater distances. We also offer pickup and delivery for cars in  Springfield, Wilbraham, Longmeadow, Agawam, Westfield, Northampton, and Amherst.