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1976 Silver Shadow brakes help please

11K views 79 replies 10 participants last post by  Grey Poupon 
#1 ·
Greetings. My friend inherited this car. It's been sitting for 19 years down south. It's rust free, a right hand drive. I've been working on it now for him, (I'm a Ford tech so this is all new to me). I got it running, new fuel pump and hoses, cleaned carbs, changed fluids, (except brake fluid), etc. I need help with the brake system. I've been reading up on it. I'm guessing from the car sitting I've got problems. When I got it started only power brake 1 stayed on and I had slight braking. After a few stops both lights are on and no brakes. 2 flexible steel braided lines by the left rear side underneath are leaking. Where can I get these lines? Should I just start over and replace both brake pumps and other parts like the accumulaters? The reservoir was full and was clean. Any insight on this is greatly appreciated! Thanks!
 
#2 ·
Any SY series car that has sat that long is going to need a complete overhaul of the braking and hydraulic system.

You will definitely need to:

1. Replace all brake hoses. I have documented commonly available hoses you can use in a table in the RR & Bentley Parts, Repair, Restoration & Other Resources Compilation. Personally, if I were ever to do this job again I would get the PTFE core, reinforced hoses like are used for the accumulator control valve to car body for all the hoses. These have a virtually perpetual service life and don't break down internally over time. Well worth the premium in price that you pay for not needing to think about this job again for many, many, many years.

2. Rebuild the Accumulator Control Valves (which isn't nearly as hellish as some make it out to be, but it can be a PITA to extract them from the car). I know I've written about that, with photo documentation, either here, on the Australian forums, or both.

3. Rebuild the Accumulators (same as above as far as source material. Pin wrenches for separating the halves of the accumulator for the rebuild, as well as the rebuilding itself, have been discussed extensively).

4. Overhaul all four brake calipers. And you may need new pistons and/or to send these out depending on the state of corrosion.
 
#3 ·
And I might add. Start at the reservoir, open the lid, drain with a turkey baster and remove the filters. Inspect for tears. Work your way from here to every wheel and inspect and replace. It's one of the major tasks on these cars and usually the "straw that breaks the camel's back" on whether it is saved or not. A shop may quote more than the car is worth.
Go for it and ask questions and at the end, if successful you will have saved a fine car. Everything you need is available. You supply the labor, $$ and patience.
 
#4 ·
Thanks for the replies so far. Should I just replace the 2 pumps then also because they have been sitting or can they be rebuilt? Another thing I failed to mention. Coolant is leaking from behind the center pulley (what I what guess is the water pump). There is up and down play when I wiggle up and down the fan. Is there a seal and bearing to replace or does that all come along with a new water pump?
 
#5 ·
I would also suggest purchasing a BA tool set consisting of spanners and BA sockets in 1/4" drive. All the small hex fasteners are BA, not Metric or fractional. The Phillips head screws are really Pozidrive and a different design so a Pozi #2 fits most of these..
 
#7 ·
The pumps very seldom need to be replaced. And that's what I'd deal with last. And I'll have to disagree with @Wraithman here. Very often these survive unscathed. Don't ask me why.

@Wraithman is correct about dealing with the reservoir first. You can find some posts I've made that show the interiors of SY series reservoirs that have been sitting for years. It's not pretty and often looks like an algal swamp (even though it can't be algae) at best and a pool of deep rust at worst.

If your filter screens have collapsed then once you use a pencil to pop them back up, and clean them, you must make sure that they do not have any holes in them. If they do, I'd strongly suggest NOT getting OEM ones again, but ones like Kelly at British Tool Works makes that will not collapse.
 
#8 ·
Also, the fluid feed hoses from the tank to pumps have to be replaced. All hoses whether coolant, and especially brake hoses must be changed. The internal breakdown is responsible for the blackish color of the old brake fluid.
 
#9 ·
Although the pumps seldom fail, they are not immune to internal corrosion and litter from reservoir filter screens with a hole. As a matter of practice I repair,replace,restore, everything in the circuit. I leave no stone un-turned.
 
#10 ·
As a matter of practice I repair,replace,restore, everything in the circuit
And for that, you are to be commended.

But many of us do not, and if the car has been started without "major incident" with the brake pumps the process of doing a thorough flush and bleed tends to purge any very small floating detritus such as the breakdown products from the hose interiors.

Your approach certainly cannot be faulted. But some of us aren't ready to follow it. I know I never have. I attack all "points of likely failure" based on what's known, or not known, about the history of the car and I only deal with the pumps if there's a clear indication that's necessary.
 
#11 ·
You say in your initial post that the brake reservoir is clean and full. Did you remove the top and baffles to inspect the filters? If your reservoir filters are collapsed I make new ones from stainless steel which are guaranteed to never collapse.
Cosmetics Adhesive Finger Cylinder Tool

Before removing the pumps make sure the reservoir is truly clean and that the filters are not torn. If they are good then the pumps may be OK. Test them by removing the outlet pipe from the top, then crank the engine over with the coil lead removed and see if brake fluid spurts from the outlet. If so then you can likely leave them alone for now, but pull off the outer housing while you have the outlet pipe off and replace the two O rings that seal the housing to the pump. You will need a special castle socket to remove the pump if you need to rebuild or replace them but the outer housing will pull off by hand to replace the O rings. Next go to the accumulators which will definitely need overhauling if your brake warning lamps are illuminated. I also rebuild the accumulator valves and spheres on exchange, and test and shim the relief pressures to the correct value before shipping back.
Motor vehicle Automotive design Gas Auto part Machine

Rebuilt accumulator valve and sphere on test rig.

As mentioned previously you absolutely should replace all hoses in the system, and overhaul the calipers too. As I'm sure you know the brake fluid will have a lot of moisture in it from all those years of sitting without use and that will cause a lot of corrosion in the system. Caliper kits, pistons, and hoses are not too expensive if bought aftermarket.
 
#13 ·
Jim, I didn't know there were filters. Where exactly are they located? I only removed the big cover and screen to check the fluid level. I will get back to you then on those filters. Also I'm thinking maybe I should remove those accumulaters and valves and send them to you for repair. What would this cost? I'd like to mention this to my friend. I really appreciate everyone's feedback so far. It's all very helpful. I've been working on cars for 28 years at the Ford dealership and never have seen anything like this brake system. This car is very advanced for is age. Even with the electric gearshift on the Trans. It's a feature that the new vehicles have now today.
 
#15 ·
Grey,

The baffles in the reservoir are attached to the central divider by a simple nut and bolt. If you remove these, the baffles lift out (go straight up and don't break your floats) and you can then have access to the bottom of the reservoir and filters attached there.

See 1979 silver shadow brake system | Rolls-Royce and Bentley Forums (rollsroyceforums.com) and 1977 silver wraith II brakes locked up??? | Rolls-Royce and Bentley Forums (rollsroyceforums.com) (sadly, the images in the second topic went up in smoke when the forums software changed, but you can see the reservoir interior photos with the baffles in place (first photo) and removed (second) in that initial topic.
 
#16 ·
#17 ·
Rolls-Royce Silver Shadow Website (by Marinus Rijkers) http://www.rrsilvershadow.com/EIndex.htm
An absolute treasure trove of information regarding the Silver Shadow and derivatives.
Including, but not limited to: models, paint/everflex/upholstery/top-roll colors, animated demo
of the hydraulics, etc., etc., etc.


The animated demo of how the brake and hydraulic system works is well worth taking the time to watch and to understand.
 
#20 ·
This is what the reservoir can look like from a Shadow with failed brakes and poor service history. The muck in it is debris from deteriorating hoses and corrosion of internal parts of the system. This is why the baffle must be removed to inspect the filters. In the forward compartment you can just barely see the top of a collapsed filter, and a reasonably good one in the rear compartment. This is what happens when the brake fluid is not flushed out and changed every two years.
Fluid Gas Liquid Cuisine Dish
 
#21 ·
Great idea on removing the lines at the pumps. The front pump has great supply of brake fluid to the pump but it is like syrup, and nothing comes out the top at all while cranking the engine over. I removed the carbs, I cannot get the supply line off, I need to bring a stubby wrench home. But I removed the top line, cranked the engine over and I get a little pulsing of brake fluid coming out but not a whole lot. How much should be coming out? They look like a rusty mess. The front one needs to come out for sure. Maybe the push rod is broken or the pump just corroded.
 
#22 ·
How are the filters? If clogged you will get little or no fluid from the pumps. Have a good look at the feed hoses from the reservoir to the pumps, are they spongy or weeping through the surface? Guys mistakenly use fuel hose for them which brake fluid attacks causing them to swell and sometimes close off internally. EPDM hose must be used for that application, 3/8ths heater hose is what is required. The pump plungers can stick up from corrosion, as your car has sat unused for so long they may have gone up on the first stroke and stuck there so don't assume the pushrod is broken. Had a pump like that on a client's car just last week. You should get a good six inch spurt if the pump is getting unrestricted fluid from the reservoir.
 
#23 ·
As others have said, start at the reservoir.

These cars - all elderly cars - suffer from catastrophic deterioration of the brake fluid when not changed or left unused for long periods. It absorbs water from the air. I am half-way through the repair of a Shadow which had been little used for several years. The reservoir filter were collapsed, and the fluid had black gunge and yellow jelly in it. Nearly all the brake pistons were rusted solid because hoses or valves were clogged preventing the pistons from relaxing off, which causes the brakes to rub, which causes the caliper assemblies to get VERY hot, which causes the dust seals to distort or even melt, which lets water into the ends of the caliper cylinders, which cause them to grip the pistons tight, or some other sequence of deterioration in the same loop. It must all be good, or it "snowballs" into this condition - one problem causing another. Note: the reservoir lid is held on with 2BA screws - some of them have nuts which are easily dropped and lost.

DIY repairs to this area will save a lot of money, but you must be prepared for problems such as stuck/rusted pipe joints. HINT: only ever use 6-point flare-nut spanners on hydraulic joints - NEVER 12-point, especially if the nut is rusty - it will round off the hexagon and the only solution may be to cut the pipe. A long-term solution is to use stainless-steel replacements in repairs.

I solved the problem many years ago by using DOT5 silicone brake fluid, and have not suffered from these problems since. (Note - not DOT5.1). Some people will say "No, no, no!" but the rubbers used in seals today are very different to the material used in the early days of the Shadow. And the silicone oil discourages rust and does not attack paint, though sprayers hate it - it is difficult to clean off painted surfaces. (Discuss.)

Incidentally, I think that brake pads absorb water too. It would explain why brake pads shatter in a characteristic way when brake systems suffer in the way described. When the brakes are applied for the first time the water in the pads boils and shatters the pads. Anyone else noticed that?

Alan D.
 
#24 ·
Thanks again for the info!! Tonight I took apart the reservoir and sucked out the brake fluid. It was like you all stated, full of sludge under the plates. The filters are collapsed.

Question. Would it be ok for me to put some dot3 or dot5 in just for testing purposes, since I'm going to be replacing the accumulaters valves and hoses etc?
 
#25 ·
There would be no point in testing right now. You will be moving the **** around. You have a way to go to clean,rebuild and replace. Wait until everything is done and use brake fluid to test and check for leaks.
 
#26 ·
No harm in doing that, use DOT 3 or 4 and see if you get any pressure build up. Don't use DOT 5 silicone! Bear in mind that once you have it cleaned and refilled and the engine running again the muck in the rest of the system will be pumped back into the reservoir so if the filters are ripped it will be pumped into the pumps. If the filters are already ripped then it doesn't really matter as the pumps will already be full of muck and you're going to have to strip and repair all of the brake system anyway to make the car safe to drive. Might give you some short term satisfaction if you can get it to build up some pressure after cleaning the reservoir but don't think it will be safe to drive without a major overhaul.


.
 
#27 ·
After cleaning the reservoir I put regular brake fluid in for now because I needed to move the car in my shop while waiting for parts. Now only brake system 1 red light stays on and the car has some braking. I was glad to see that. I'm guessing there is an issue with the front hydraulic pump. It has brake fluid supply but nothing comes out. I will update this post when new parts are installed. Lastly, how are the caliper Pistons replaced? Do you need new seals? I've never replaced Pistons before. Thank you.
 
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