[guyslp]

If the sphere was correctly rebuilt (and it should have been) and using the FS improved charge port valve (and it should have) I would imagine you'll still have adequate charge at 5 years.

That being said, you've got 'em off. It's a simple matter to find someone who can charge them to the required 1K PSI (or ever so slightly above) while you have the chance. Aircraft use nitrogen charged accumulators by the dozens, and that includes even small private aircraft. Asking around at your local small airport will likely find you a source or sources who can check and charge these while it's just so darned easy to do!

 

[Steven R Morris]

Thanks Brian,

You're right, I'm in now so just as well get it checked..

Heres an interesting one....

I have ordered a front calliper seal kit as the front brake are just about starting to stick, and while the systems down I may as well cover all bases in one go..

A while ago I ordered new bleed nipples, for all the callipers, as the ones on the car looked maybe original, and today I removed the front callipers and stripped them, to find some corrosion on every one of the pistons, but the callipers are OK, so I will fit new pistons of course. Thats not the interesting bit.....

I split the first calliper, pulled it apart, cleaned it up as I will paint it before re fitting of course, and tried one of the new bleed nipples in the old calliper body. upon tightening it something didn't feel quite right, you know that feeling after years of tightening bolts? on closer inspection the nipple is 'loose' up until its tight, so I inspected the threads against the old nipple, its a 3/8 alright, but the TPI on the old nipple, and therefore the calliper is is 3/8 26TPI, and the new nipples are 24TPI. I haven't had the chance to call FS as they are closed now, but did early nipples differ? I thought they were all 24TPI?

So then, I looked at the brake pipes (between flex and calliper) and on re fitting them they are the same! Someone has fitted new flex hoses and copper pipes to the callipers, (x4) but used the wrong male ends! They tighten, and did of course hold (I have covered over 2000 miles in the car), but they are wrong! I am now in need of 26TPI male brake pipe unions as I need to change them ends, can't imagine even driving the car now without thinking what might happen if I emergency brake with new accumulators?!?

Any thoughts on the different thread pitches though? I did order the nipples for my car (1973 SS SRH16768). Could it be that I need the metric ones? On FS website it says Metric are fitted to cars AFTER 1974??

Confused, it doesn't take much...!

Regards,

Steve.

 

[guyslp]

Steve,

If you have not already done so, please download: RR & Bentley Parts, Repair, Restoration & Other Resources Compilation (which I've been maintaining for far longer than I care to admit).

Then search for the page with the heading: Rolls-Royce Silver Shadow/Bentley T and Silver Shadow II/Bentley T2 Hydraulic Hose Substitution Chart

I put this together many years ago, I think it was 2009, but it might have been earlier than that, and I am meticulous about my documentation. I note, at the top of that chart:
Functional substitutes are shown in red (all are SAE J 1401 – 1/8 HL – DOT rated hoses, just like Crewe)
All of these hoses have 3/8-24 Male fittings on both ends and some of the hex heads are 5/8” NOT 9/16” like before!!
All except GHP3 have flare fittings on both ends; GHP3 has a 3/8-24 flat O-ring fitting on one end & uses a copper washer.

Note also that the majority of the Crewe OEM part numbers remained stable for the duration of the SY car era, and even those that did end up with changed part numbers could not have actually had changed fittings.

 

[Kelly Opfar]

Some front Girling calipers have metric bleeders and brake fittings. I have both styles of caliper in stock.

 

[Steven R Morris]

Thanks Kelly, I believe I have Metric callipers then? Do you know the size? Would they be M10 x 1mm?

 

[Kelly Opfar]

10mm x 1mm pitch is correct.

 

[shadow 11]

Kelly supplies stainless steel brake pistons that shouldn't suffer from corrosion issues.

 

[Kelly Opfar]

Stainless Silver Shadow/Spirit Front and Rear Caliper Pistons | britishtoolworks

These are new stainless Shadow/Spirit/Spur caliper pistons. They are guaranteed to never rust. The largest one (CD4072/CD5737/CD5844) is for all front calipers.The smallest one (CD4074) is for all rears. The medium piston (CD4073/CD6283) is for the rear on early Shadows with the master...

www.britishtoolworks.com

 

[Steven R Morris]

Ive had a chance to play in the workshop today, made a video re brake pipes that were fitted by a clown....

And the pipes, cleaned, checked ready for the flaring tool...

 

[guyslp]

Good for you for choosing cunifer line for replacement. I'd never even consider using mild steel ever again.

 

[Steven R Morris]

Its all I've ever used Brian, I used to restore old Jaguar's and have made pipes in my sleep!

 

[guyslp]

Its all I've ever used Brian, I used to restore old Jaguar's and have made pipes in my sleep!

Well, I wish I could say the same thing. On SRH33576 I actually had to splice a brake line at one point so had to flare the existing mild steel line in situ (and in the engine bay). I am virtually certain I posted about this, including photographs of the work in progress and finished. Flaring mild steel is hell compared to cunifer, not to mention it rusts. I definitely believe these cars would have had cunifer line straight from the factory had such been in use at the time.

It's corrosion resistance coupled with its being so much easier to bend and flare makes it a "no brainer." Originality be damned, I'd just never use mild steel brake line when replacement is needed.

 

[Steven R Morris]

Another question for the learned…

does anyone have or kwhere I could find pictures of the correct routing/bends on the front metal brake pipes on a 1973 Shadow with vented discs please? The pipes as explained in the video were clearly fitted by Stevie Wonder and I want to re fit them as close to factory as possible.

thanks in advance,

Steve.

 

[Steven R Morris]

OK, so its been a while since I posted and the car has been waiting for a gap in the work schedule but I finally got it back together today, but,.......

The reason I started this was because of low pressure in circuit 1. the low pressure light came on after about 6 pumps, but circuit 2 had a dodgy pressure switch so I couldn't really tell whether or not that side was low as well (yes I should have done a pressure test first before stripping it all off!)..

So, I fitted a re-conditioned sphere to circuit 1, from FS. I confirmed this was empty of nitrogen as I could push the charge valve and a small psst was heard, then nothing..

I decided to fit only one sphere as the circuit 2 sphere had a warranty sticker on from FS, and when I spoke to them quoting the number it was 3 years old, so I decided to take a chance and re-build the switch, then see how it was fitted.

I also rebuild both ACV's as well as both low pressure switches and front calipers.

So, the result?

Ignition on, both circuit 1 and 2 low pressure lights work and are on, a good start. Ran the car, lights went out almost straight away, pumps appeared to be quiet, got enough RR363 in the reservoir and after about 3-4 minutes the returns from both ACV's started working (could see the flow up from them in the reservoir).

All good? did the acid test. Car had been running for around 4 minutes, and I assumed that the ACV's must be working and system up to pressure as I could physically see the returns working. So, switched car off, ignition on, and began to pump the pedal.

Low pressure in circuit 1 after 39 pumps....Bugger......!
Low pressure in circuit 2 after about 110 pumps, well at least the second circuit sphere is ok.....!

So, I got a the last piece of the jigsaw for making the pressure test tool (Jaguar E Type series 1 front brake flex-hose), and set about testing the circuit 1 pressure.

I connected the gauge to the bleed nipple outlet in the circuit 1 ACV, and started the car.

Flick up pressure within 10 seconds 1000psi.

The gauge then rose steadily and after 3 1/2 minutes it had achieved 2300psi, then it dropped back to around 2000psi and seemed to settle there.

The figures suggested all is OK, so I switched off, then got someone to pump the pedal while I watched the gauge. After only about 20 pumps, and the gauge was going down a little bit each time the pedal was pumped, the gauge appeared to drop straight to zero. I released the bleed nipple on the gauge tool, just to check there was zero pressure, and there was. Started up again and it flicked up to 1000psi almost immediately again, then did the same, rose to 2300psi then dropped back to 2000psi.

Any ideas!?!?!?

Yours 'disappointedly',

Steve.

 

[shadow 11]

Did you bleed the complete No.1 system including the pressure switch prior to doing the pressure test. My guess is that there's air somewhere in the No.1 system or a minor leak causing pressure loss because the initial gauge readings are good until you start pressing the brake pedal. If you attach the pressure gauge to the high pressure outlet on the accumulator control valve and do the test again and get good results that would signify a loss of pressure somewhere in the brake lines or brake distribution valve. The way to find out where is to systematically move the pressure gauge along the various bleed points until you get a satisfactory reading. The problem doesn't appear to be at the sphere or ACV but taking a reading at the ACV high pressure outlet will confirm as that will blank off the remainder of the No.1 system.

 

[Wraithman]

Factory workshop manual TSD2476 under Section G you will find a diagnosis chart. You will have to print each side and tape them together. I'm fortunate to have this in the form of a factory wall chart. This and your gauge will help you immensley.

 

[Steven R Morris]

Thanks chaps. Great shout re air in system. Absolutely massive schoolboy error on my part, I hadn’t bled the rear callipers out….Doh!!

So, attempted to bleed the rear callipers using the same method as the fronts, length of wood on the pedal, seat moved forward etc then engine running, no dice. Can’t seem to get anything out of the callipers? My car‘s chassis is 16768 so according to the workshop manual the upper nipples on the rear callipers are fed off number 1 circuit, but nothing? I did try the lower nipple in case someone had piped it up incorrectly but again nothing.

I initially suspected the G valve, so locked up the nipples, moved the car around, tried again, nothing?

Something is odd though, if I press the pedal hard or quickly, I hear and feel a clunk from inside the rat trap, so I removed it to find everything looking normal, no leaks (except the usual residue in the bottom of it which I suspect is the diverted valves seeping, which is quite normal?). I bled the system through last year and got fluid at the rear no problem, so don’t quite understand what could have changed?

Has anyone experienced this before?

Wraithman, thanks for the manual link, the manuals are on my laptop, I’ll take a look and print them out later, great shout re taping the, together as well. I did this when chasing a wiring fault on my wife’s MB..

Thanks again, love this forum!

Steve.

 

[shadow 11]

Sounds like the ball bearing in your G-valve has blocked the fluid supply to the rear callipers. This can happen if the calliper bleed nipples are opened too quickly. The G-valve should reset itself if you depressurise the system by pressing the brake pedal a number of times with the engine off until the brake pressure is released.

 

[Steven R Morris]

Thanks I’ll give it a try tomorrow!

 

[guyslp]

I have a quick, "Refresh my memory, please," type question: How is it that you remove the bobbin from the ACV?

I recently received this picture (and let's not get into the condition of the Sealing disc in it:

And what my hazy memory recalls is that I used some sort of small hook in one of the holes then gave a firm tug to break the grip of the existing seals on the ACV body and just slid the thing out. The problem is, I cannot honestly recall what I did, or if I even needed to do that, since it could have been that the regulator valve spring was pushing with enough force to let the thing come out once the end plug was out.

I just don't clearly recall this over a decade later.