| Author | Message | ||||
     Bob Reynolds Prolific User Username: bobreynolds Post Number: 107 Registered: 8-2012 |
1975 Silver Shadow with master cylinder. After changing the rear discs and calipers, the brakes are now either all-on or all-off. Nothing happens until the pedal is pressed about half-way down, then the pedal suddenly meets hard resistance and the brakes come full-on. What could cause this? Is it a bleeding problem? (pun intended.) | ||||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1217 Registered: 6-2006 |
sounds like air in the brakes. what happens if you push them quarter way down then hold it there or push it down really slowly.? | ||||
| richard george yeaman Prolific User Username: richyrich Post Number: 176 Registered: 4-2012 |
Hi Bob at the moment my 1974 Silver Shadow has the same problem when this has happened in the past bleeding was the answer good luck. Richard. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 873 Registered: 6-2009 |
I also had a similar, but not quite so "all or nothing," effect in my Shadow II at one point. You'd press the brakes and they'd come on, distinctly weaker than usual, then suddenly "step up" to stronger than usual (or seemingly so) without having moved the pedal at all. It was solved by bleeding the system thoroughly (even though I thought I'd done that already). Brian | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.76 |
The master cylinder circuit is faulty I suspect that when the brake is applied the master has no pressure and the lever that pushes the master cylinder push rod is hitting the safety spacer between the brake mechanism frames This will make the brakes an on off switch no feel or feed back from the master cylinder Remove rat trap! The spacer is alloy 1 inch dia Remove one bolt so that full stroke is available. Then open caliper nipple. Dot should freely flow in steady drips Otherwise blocked hose Shut nipple pump up until pedal hard then open nipple dot will fly out and pedal will sink If the system will not pump up the master cylinder has failed Remove outlet pipe from master screw in bleed nipple from caliper and try if the master doesn't lock solid then it's definitely faulty and not air The rest is obvious put the spacer back If you remove the master when reffited Adjust push rod so that brake binds them back off stamp on pedal and check On road test have tools to adjust immediately binding shows I suspect that when the caliper pistons were retracted and pumped out again the master packed up Brake masters don't move much and can get worn at the front when the seals hit the ridge----- Clutch masters last better (Message approved by david_gore) | ||||
| gordon le feuvre Experienced User Username: triumph Post Number: 39 Registered: 7-2012 |
Don't forget the fluid reservoir. The gauze over the feed pipe really does block with sludge and won't allow enough fluid through to m/cylinder when bleeding, but you wound not notice in normal road use. Citroen had a removal filter in fluid reservoir that could be easily cleaned, I assume R-R just expected ALL cars to have correct hydraulic service every 8 years/96000 miles, but most have not! Take screws out of reservoir top and have a look in if your NOT sure it is all clean, This applied to any Shadow. | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.74 |
Good point If dot doesn't drip readily when caliper nipple is opened then the first check is to whip the lid off for filter check The dot should be clean enough to see the filter Don't leave lid off for long time moisture in surrounding air (Message approved by david_gore) | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 877 Registered: 6-2009 |
While I agree that a reservoir check and cleaning should be a part of a thorough going-over on the brakes/hydraulics, even if the screens were blocked it shouldn't result in the issue that started this thread. I had that happen on my Shadow II (and after a so-called complete going-over by a RR specialty shop) and the result is that there is not enough fluid for the pumps to keep pressure in the accumulator and you typically get a pressure warning light. Here are the two pictures I've posted before, one from my Shadow II and the other from my Wraith II, to show how awful things can become after neglect. SRH33576 Reservoir  LRK37110 Reservoir  And if your filter screens have been clogged, collapsed, and been popped back out again one time too many, eventually this is what you get:  which inspired me to have an alternative made that, while it will clog if things get messy (which I'm preventing), it will not collapse:    Brian | ||||
| Bob Reynolds Prolific User Username: bobreynolds Post Number: 109 Registered: 8-2012 |
Thank you everybody for your very useful replies. Looks like the Master Cylinder system is the culprit. Hopefully it will just need bleeding (again). I will be continuing this job later this week. The hydraulic tank was completely overhauled last February and all filters and screens and rusty screws replaced. And yes, they did look like those in your photos Brian! | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.86 |
Notice that the outlets and inlets are not right at the bottom leaving room for the sludge to sit The sludge is the additives in the dot which have attacked and surrounded foreign bodies The tank because it is large compared to a pipe slows the dot down so that nastiness drops out My car was similar when I got it I marvel at how well the system is designed (Message approved by david_gore) | ||||
| gordon le feuvre Experienced User Username: triumph Post Number: 40 Registered: 7-2012 |
It still a shame R-R did not adopt LHM from day one. It would have saved so much effort, I wonder what the reason was. Loads of early cars had to be repainted as flex. pipes had a habit of coming off crimps. This happened under car, so that the fluid would hit the road on motorway and be sucked back over rear/boot. Also the pipe between the brake pumps and accumulators (that were flexible at that time) used to chafe through as each pulse of pump made them flex. This resulted in brake fluid being squirted over engine and squeezed out of gap at edge bonnet. No good for paintwork. That is why R-R changed to rigid pipes as a retro fit, and suddenly brake pump "knock" was born- but that is another story! | ||||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3028 Registered: 4-2003 |
The answer to that is straightforward. A braking system with a master cylinder needs a hydroscopic fluid such as DOT3/4 - based RR363. Over time it soaks up water and the boiling point lowers slowly and safely until it is changed when scheduled. LHM, is not hydroscopic, neither is DOT5 Silicone fluid for that matter, so the inevitable moisture from spillage and condensation stays in suspension as tiny droplets rather than dispersing into solution such as with DOT3/4. Those droplets in the LHM inevitably find their way to the lowest points in the systems, ultimately at the calipers. As soon as any such droplet hits a hot brake caliper piston it boils instantly leading to a complete failure in that system if it relies on the tiny capacitz of a marster cylinder. On an SZ, as it has no master cylinder (nor does a late SY of course), the vaporisation is compensated by a large reserve of pressurised fluid in the accumulators, so any boiling water droplets are rapidly overcome by applying more fluid without the driver even noticing anything wrong except if the moisture level is very high. In a really bad case, the driver may notice a slight delay in braking part way through slowing down while the fluid catches up with the vapour produced. That is the reason silicone fluids were hurriedly abandoned soon after they became available and touted as moisture-proof. Many an enthusiast of cars with conventional braking systems has come a cropper when experimenting with silicone fluids early on. As an aside, RR363 seals, especially in the brake pumps and calipers, seem to outlast the LHM ones of SZ cars by a large margin. There’s not much in it really. LHM lasts a very long time between changes compared to DOT 2/3 fluids (2 years), but calipers and other hydraulic components seem to need overhaul because of leakage much earlier. This is reflected by sales of those components, where sales per 1,000 vehicles of seals for SZ LHM systems outstrip those for SY RR363 systems by a huge margin. RT. | ||||
| Randy Roberson Prolific User Username: wascator Post Number: 239 Registered: 5-2009 |
Free water can also freeze in a brake system and block it. | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.85 |
LHM was adopted because dot doesn't work as well as a damper fluid in the rear strut gas spring and shock absorber The advantage of dot is that it absorbs water protecting the system 3% is max in service I have seen dot unchanged for years and the system still functions all makes LHM is not a long life fluid and must be changed about the same as dot Water will get in and it will mix when it gets to the pumps and then drop out and settle at the lowest point I recommend 2 years for both Which is actually a large overkill Both oils are cheap in comparison with say a brake pump So £100 for Dot and £40 for LHM is a must Also my 3 Citroens were all LHM and they all gave trouble with leaks I got very good at fixing them I have had no problems with the RR car Dot5 not 5.1 Dot 5 is silicon and has less oilyness than dot and must not be used in pumps and abs systems The only thing I dislike about dot is its paint stripping ways (Message approved by david_gore) | ||||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3029 Registered: 4-2003 |
Interesting is that the Citroën C5 I usually drive for work has conventional brake fluid. Citroën dumped LHM when the early C5 was introduced in 2001. And, yes, it is a peppy Turbodiesel which consumes 5 Litres on the highway at 110. Being fully-loaded with wonderful leather trim and every gizmo as modern cars have, rolling up to Customers is more subtle than in a Continental. Saving 100 litres of fuel each week is a small bonus. | ||||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 885 Registered: 9-2004 |
My C6 also has conventional brake fluid just for the brakeing system. The hydroactive 3+ suspension uses LDS fluid, not a mineral oil and so it is hydroscopic just like my Shadow 1 and 11,change fluid without fail every two years. The power steering also has its own oil system no filter so have fitted a magnet!. What a car never to be built again with all the bells and whistles. Head up display, lights that turn to see round bends,Juke box, voice recogniton etc etc. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 878 Registered: 6-2009 |
Not that Citroën markets in the USA (so we'll never have them), but does anyone know whether the company has any plans to take the Metropolis Concept to production in any form? Ever since seeing this concept for the first time I've been in love with it. Brian | ||||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 886 Registered: 9-2004 |
Brian I believe the car is made and marketed in China, an estate is also produced. Like the 166mpg range but still needs fuel not like my all electric LEAF. Do not know if it has the hydroactive suspension that the PSA group say will be discontinued at the end of the year, if they get their way. http://www.mesopinions.com/petition/autres/contre-abandon-psa-systeme-hydropneumatique-citroen/11030. http://www.citroenet.org.uk/prototypes/ds9/ds9-1.html
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| Brian Vogel Grand Master Username: guyslp Post Number: 879 Registered: 6-2009 |
I doubt that the Citroënistas will go down without a major, major, major fight on the hydroactive suspension. I so wish the Metropolis were available where I live. It's one of the best looking sedans I've ever seen. Also, I'm not sure what the attachments are "supposed to do" but I can't get them to open. Brian | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.88 |
I have always liked Citroens and have noticed that other RR enthusiasts also do The C6 is a smasher and as James May from old men in denim said it will be a flop and he was right Which is handy because I have seen these as low as £6000 so if you fancy a C6 as a second car Citroen have made lots of good cars that devalue to near zero and then 30 years later they shoot up in value like the 2CV SM DS and now the CX is showing a slight increase So if you get a good C6 and look after it it will eventually go up in value and it will be a rare old car Only if you like the C6 though (Message approved by david_gore) | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 880 Registered: 6-2009 |
I can't say that I know anything about the C6 other than what I've read and what I've seen in photos. Based on the photos alone I would have been standing behind Mr. May and seconding his notion. It sounds like it's a technological tour de force but the exterior styling is about as bland as one can imagine. It's visual Xanax. Brian, who lives in a country where French and Italian cars (ignoring exotics) have never really been able to "make it" when they've tried | ||||
| Bob Reynolds Prolific User Username: bobreynolds Post Number: 110 Registered: 8-2012 |
"Citroen have made lots of good cars that devalue to near zero and then 30 years later they shoot up in value" That's because nobody buys them, and so they then become rare.  | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.71 |
They sold quite a few many more cars RR I used to warn buyers of rare cars that the car could be rare because it was s**t Daimler dart is a horrid car that didn't sell it looked like an ugly fish plus it wasn't that nice to drive yet collectors pay loads People like ugly dogs (Message approved by david_gore) | ||||
| Bob Reynolds Prolific User Username: bobreynolds Post Number: 118 Registered: 8-2012 |
Ok, there is finally a resolution to this. Everybody was right about it being the master cylinder circuit, but it was not a simple fix. The system was bled multiple times, both with a vacuum bleeder and by pedal until no air. No improvement. Blocking off the master cylinder did lead to a harder pedal, but not as solid as you would expect. So a new master cylinder was bought and fitted, as this was the only thing that hadn't been changed. Bled with vacuum bleeder until no air. Result: Just the same.  Ready to give up altogether and set fire to car. Next day system bled again with VB - plenty of solid fluid coming out and no bubbles. Surely it must be fixed now? No improvement. So bled with pedal and lots of bubbles now coming out. Continued bleeding with pedal until no air. Problem fixed. The professional mechanic who was helping me has never seen anything like it. He uses the VB all the time and it ALWAYS does the job. All the advice on the Internet and other sources is to use a vacuum bleeder on this master cylinder circuit, as the pedal is next to useless and won't do the job. Well not in this case. I was the person who asked about dumping the master cylinder and swapping the rat trap for a Shadow 2 rat trap. I almost wish I had done now! Changing all the hydraulic pipes and calipers would have been much quicker than bleeding the master cylinder! | ||||
| Bob Reynolds Prolific User Username: bobreynolds Post Number: 119 Registered: 8-2012 |
Some things I've learnt from this job: Bleed the master cylinder circuit using the pedal, and push it down really hard, not slowly. Release it slowly. The bleed nipple on the deceleration valve is no longer on the valve itself, but has been moved to a much more accessible spot on the side of the rat trap. The master cylinder comes on before the power brakes operate, and not the other way round. RR363 is out of stock everywhere, and FS say that Castrol will not be making any more until late December or even next year. They are working with Bentley/Castrol to try and rectify this ridiculous situation, which should never have arisen. The main brake valves are not servicable, and a new pair will cost you £1200. FS sell second-hand ones, but they are not reconditioned, just cleaned up and tested. This is not their fault, the valves are not meant to be serviced and parts are not available The brake valves are designed to leak slightly (yikes). Exactly how much they are allowed to leak before you pay out £1200 is not certain. | ||||
| Randy Roberson Prolific User Username: wascator Post Number: 249 Registered: 5-2009 |
The Metropolis looks a lot like the Cadillac V-16 concept car. Also somewhat resembles the latest Jaguar styling direction. It is an attractive car. I am always attracted to Citroens: maybe because they are so unique. Also, the Panhard Dyna Z fascinates me. I think some of the attraction is the attraction we have for the unfamiliar; part of our natural curiousity. The fascination for a unique machine, vs. the need for practicality and limited money to spend are in constant battle... Someone figure out how to modify the main brake valves to include an O-ring seal. Mine leak 'some', but not thousands' worth! | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 900 Registered: 6-2009 |
Bob Reynolds wrote: RR363 is out of stock everywhere, and FS say that Castrol will not be making any more until late December or even next year. They are working with Bentley/Castrol to try and rectify this ridiculous situation, which should never have arisen. Sadly, this "ridiculous situation" is happening repeatedly and is almost certain to happen again. The fact that it is an ongoing issue strongly suggests that Castrol's support for ongoing production of RR363 is lax, at best. I've had SRH33576 since 2006 and, if memory serves, this is at least the third "supply problem" cycle that's occurred since then. All have been of months-long duration. This was one of the main things that precipitated my move to YAK363. If the stuff isn't reliably available that's a major issue, and it's not reliably available. One of the usual sources here in the US posted a warning on its website this month that they had a few bottles left but once those were gone there would be no more until at least October. FS apparently has been given an even later production date, so who knows? I wish Bentley were more inclined to determine a replacement for RR363 that is readily available off the shelf worldwide. But since the cars that use it haven't been produced for coming up on 25 years now, that's simply never going to happen. Brian | ||||
| Bob Reynolds Prolific User Username: bobreynolds Post Number: 120 Registered: 8-2012 |
As I understand it, Bentley are committed to supporting all heritage Rolls-Royce cars. After all, they still have a dealer network servicing and maintaining these classic cars. So I would think that the shortage affects them just as much as it affects us (probably more so). My understanding is that, if the situation becomes desperate, Bentley will come up with a replacement, even if it's only a temporary one and the system has to be flushed out afterwards. I don't suppose it will be very cheap though! I have no insider knowledge, just what I've picked up from speaking to various suppliers. | ||||
| Randy Roberson Prolific User Username: wascator Post Number: 250 Registered: 5-2009 |
At the risk of being an arrogant tyrant, as is the nature of Man, and telling others what they ought to do with their property, I suggest that, whenever Castrol no longer want to provide RR363, they somehow pass the formula along to either Bentley, or to RREC or some other hobbyists' club, so the hobbyists can get it. After researching as far as I could take it without travel and resorting to industrial espionage, I concluded that RR363 is 95% DOT 3 brake fluid, and 5% "castor oil, ethoxylated, propoxylated", which is a commodity industrial chemical, a modified castor oil which increases its emulsibility and lubricity. At any rate, other than the usual costs of any corporation, and the loss they probably take on making it, there is not much to it. Latest price from my source seems to be $160 for four liters. At $40 per liter, one of the clubs could mix up a batch and bottle it, or else have a "house brand" supplier make it up. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 902 Registered: 6-2009 |
Bob, Bentley has a limited commitment to supporting heritage Rolls-Royce and Bentley motorcars, and that's only for parts and for cars 1955 and later. You can see for yourself on the Bentley Heritage Support page. There are no heritage training programs in place so there will be no "officially certified" Bentley-trained mechanics for the heritage cars. Most of the dealerships don't have a clue as to how to handle cars earlier than the Seraph/Arnage era, at least in the US. Those that are lucky enough to have "old-timers" do, but those dealerships are very few and far between. I don't think that Bentley will spend a single cent coming up with a replacement for RR363, though I devoutly wish that they would. Brake fluid technology has changed quite a bit since RR363 was formulated even though the DOT specs themselves have not. It would not shock me to learn that any number of off-the-shelf DOT3 formulations would probably work as well or better than RR363 does, but there is absolutely no way of knowing that unless Bentley were to do the necessary research of the specs of currently produced fluids, which they could certainly obtain, against RR363 specs and they've shown no indication of doing that. I don't think you'll have any formal "on the road" testing since the pump technology in question is no longer produced. No one has been able to produce "the details" about what makes RR363 so different from other currently available DOT3 formulations. We always get the vague, "DOT3 with additives to lubricate the pumps." After the Heritage Parts Tour of several years ago, which seemed to me to be Bentley's way of selling off as much of its NOS parts as possible as quickly as possible, it became clear that parts support is likely to get much sketchier as well. I have no "insider knowledge" either, but am reading either "the tea leaves" or "the writing on the wall." Brian | ||||
| David Gore Moderator Username: david_gore Post Number: 1399 Registered: 4-2003 |
"The main brake valves are not servicable, and a new pair will cost you £1200. FS sell second-hand ones, but they are not reconditioned, just cleaned up and tested. This is not their fault, the valves are not meant to be serviced and parts are not available The brake valves are designed to leak slightly (yikes). Exactly how much they are allowed to leak before you pay out £1200 is not certain." Hi Bob, No "Yikes" involved, hydraulic system valve banks used in industry and mining applications rely on very tight clearances for operation instead of seals to avoid downtime due to seal failure disabling the valve bank. The fluid leak is intentional to give continuous lubrication of the valve bore and piston; the leakage rate is very low and should amount to no more than a visible drop of fluid on the valve housing adjacent to the valve actuating rod. I have never pulled a RR/B valve bank down but I suspect the valve bores and pistons would have been hard chrome plated to minimise wear. For Randy, your suggestion re using "O" rings to control leakage is not practical for the reason I gave above; if it was practical, it would have been done long before now. High-pressure [2000+psi/13800+kPa] hydraulic fluid will quickly overwhelm an "O" ring seal and leak profusely.} | ||||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3035 Registered: 4-2003 |
You could imagine by reading this thread that no Silver Shadow has ever had n its brakes bled before. Vacuum pump ? Nuts. It sucks air past the seals every time. The master cylinder and wheel cylinder seals are effectively one-way valves. They stop fluid leaking out but will always alow air to enter the system if a vacuum is present. Incidentally, the best way to mess up the bleeding is to press the pedal completely down and let the master cylinder reach its end stop. That can temporarily distort the seals, and often the master cylinder piston can jam at the end position. Nothing here is news to those who have done the job at least once before. Also, as David point out the distribution valves are zero-maintenance items which last almost forever unless corroded due to disuse or bad fluid. A drip of fluid past the bore each decade is hardly worthy of any modification, and besides anyone who tampers with brakes must be a looney. RT. | ||||
| Bob Reynolds Prolific User Username: bobreynolds Post Number: 122 Registered: 8-2012 |
"You could imagine by reading this thread that no Silver Shadow has ever had n its brakes bled before. Vacuum pump ? Nuts. It sucks air past the seals every time." I am confused by your post and trying to understand it. Could you explain a bit more please? Most sources recommend a vacuum bleeder for this particular job, and they are used by professionals on all cars. You seem to be saying that vacuum bleeders are totally useless. You say "It sucks air past the seals every time". Surely that's the whole point? It sucks air past the seals and out of the system. "The master cylinder and wheel cylinder seals are effectively one-way valves. They stop fluid leaking out but will always alow air to enter the system if a vacuum is present." Where does this air enter the system? | ||||
| Randy Roberson Prolific User Username: wascator Post Number: 252 Registered: 5-2009 |
I never had much success in trying to vacuum bleed: the air seems to leak around the threads at the bleed screw and it just did not work as advertised. It did seem OK to flush, as long as not much vacuum was needed to make the fluid flow. I am an amateur, though. | ||||
| Brian Vogel Grand Master Username: guyslp Post Number: 907 Registered: 6-2009 |
This is clearly one of those situations where there is more than one way to skin the proverbial cat. I know of a number of people who always use vacuum bleeders on the master cylinder circuit, two of whom post here often: Bill Coburn Geoff Wooton Jon Waples recommends using a positive pressure bleeder in The Shadow Owners' Companion but that means your reservoir lid must be completely sealed, which is tricky to accomplish. He had a custom plate made that covers both openings on the lid and has material on the underside that seals to those openings while being held down. Some report doing this via pedal alone, but virtually all of them say this method is a PITA and least reliable. This task clearly has multiple methods and solutions. Find the one that works for you and then stick with it. Brian | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.80 |
Brake valves As stated the valves are designed to leak to lubricate and anti corrosion Corrosion of hydraulic bits scraps a lot of kit seen it many times Start engine wipe dot drip from valve If say in 5 mins the valve is drip free then the valve is fine Mine are wet but never drips dot on the floor Mot test leaks in general If a leak is present except dot I would wipe and carry on with the test then providing the puddle on floor is no bigger than 1 inch dia ok and advise only Dot leaks Any dot leak that I can find is a failure I am not allowed to disassemble anything such as a rat trap So if dot is dripping from the rat trap it fails (Message approved by david_gore) | ||||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3037 Registered: 4-2003 |
Just think of a conventional bicycle tyre pump. When you push the handle, the seal expands and pumps air into the tyre. When you withdraw the handle a depression is created in the tube, the seal opens up, and air re-enters the tube from the atmosphere. Pump again and the seal holds the pressure. A simple one-way valve. The seals in the master cylinder, and in wheel cylinders with drum brakes, have the same design as that bicycle pump seal. Caliper seals are similar due to the inclination of the groove but not so susceptible. Put a depression on the pressure side using a vacuum pump and air will enter the system past the master cylinder seal. That’s why vacuum pumps are usually a failure in bleeding brakes. The surest way to help bleeding is to pressurise the reservoir slightly. However, doing the procedure properly usually does the trick. RT. | ||||
| gordon le feuvre Experienced User Username: triumph Post Number: 43 Registered: 7-2012 |
THE VERY FIRST SILVER SHADOW BULLETIN FOR THE HYDRAULIC SYSTEM-G1- WAS TO CONFIRM THAT DISTRIBUTION VALVES SHOULD NOT BE CHANGED WHEN A DRIP OF FLUID IS PRESENT. THIS IS NORMAL. I HAVE SEEN CARS WITH JUST SMALL DRIP AND ALSO CARS WITH EVIDENCE OF WETNESS FROM JOINT ON RAT TRAP DIRT SHIELD. I BELIEVE ONLY WAY TO TEST IS TO CLEAN OFF, GOOD ROAD TEST. AS LONG AS THERE IS A DRIP NOT A PUDDLE ON INSIDE OF COVER, DISTRIBUTION VALVES ARE OK | ||||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1227 Registered: 6-2006 |
WOW - shouty today Gordon. Don't worry about your distribution valves is the message here. Often unused ones will wet the rap trap, but 99 out of a a 100 will dry up with use. A brilliant piece of engineering. Master Cylinders: Never in 40 odd years have I felt the need of a vacuum bleeder. Various restrictors are fitted to prevent the master cylinders sucking air back in past wheel cylinders instead of filling with fluid from the reservoir. Obviously more of a problem with remote reservoirs. Air moves more easily than liquids. If you want to use a pressure bleeder, get a spare cap and drill it and fit an adaptor to that. Never felt the need for one of these either. Master cylinder bleeding. Clamp one sides rear flexi hose and bleed the other , then swap clamps and bleed the other. Pump fairly briskly with a tiny pause in off position to allow refilling. If it doesn't come up after a couple of bleeds change the master cylinder for a new one the next size up. As fitted to Landrovers etc. Better feel with less travel. Just my tupence worth. | ||||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3038 Registered: 4-2003 |
Paul, I have read of oversizing the master cylinder with that upgrade and have never heard of a single complaint. My concern has always been that the rear pads could wear wedge-shaped due to pressure imbalance between the piston pairs. It seems that there is nothing to be concerned about. In your experience, have you ever seen the pads wearing unevenly with the oversized master cylinder ? I do like the SY brakes. They are lighter than many cars and have great feel, but when I park a Citroën and drive an SY the brakes feel deadish. Drive a bit in an SY then switch to a Citi and the brakes are just too light. The C5 I often drive is more normal than the older C5s and especially the DS Goddess cars but still needs care. I absolutely agree about the distribution valves on SY and SZ cars. They have to be the most impressive piece of any brake system design ever. It’s such a shame that so many people mess up the adjustments and assume that the design is poor. My T-Series has never had a rat trap problem, neither has it ever needed any adjustment. Cripes, it still has the original master cylinder and seals in place after 42 years and 340,000km, so maybe it’s time to fit a new master cylinder just for good measure. RT. | ||||
| Bob uk Unregistered guest Posted From: 94.197.122.89 |
No car left the factory with bad brakes and apart from adjusting the mc push rod it shouldn't be necessary to adjust anything else The adjustments are for setting up when new Only maintainance is lub the pivots and visual inspection Mc push rod once set will last until mc fails The mechanism is robust and not likely to wear Don't drive through deep water Before I adjust anything on any car I ask why Eg if a manual gbox linkage is out of wack then because it must have been ok when new so is it wear or damage If it is wear then new parts Adjustment wont fix wear it will merely move the gilch elsewhere (Message approved by david_gore) |
C6 etc