| Author | Message | ||
     Bob uk Unregistered guest Posted From: 94.197.122.80 |
A colleague told me all about GM brake hoses and dot oil. About 1994 GM investigated having dot fluid last the life of the car. GM rubber brake hoses have a PTFE liner to keep water out. GM tried silicon fluid which gave problems with valves. Silicon compresses and it is slow to react. The abs valves can't cycle because the oil is compressing and uncompressing slower than the cadence of the abs. GM chemists tried valiantly but so far haven't come up with anything that works. Then main problem always seems to be the rubber or whatever the seals are made of. So GM went back to glycol and are still working on the problem, but kept the hoses. My mate says he has cut post 1995 hoses open to find a white liner. Which he's says is Teflon. PTFE. Maybe he's right. It does make sense if one wanted a oil to last for say 20 years then so must the other bits. It's pointless having longlife oil if after a while the hoses need changing because New oil will be needed. I explained about RR363 and he said that GM tried polythene as a lubricant. So we looked up dot in the sae book and dot 4 has 20% polythene. Or was it polyethylene not sure. The rest is borate esters. LHS has 8% castor oil. No mention of RR363. Also the dot specifications make no mention of what has to be in dot oil just what it must do and what it must not. Meaning that if yak milk could pass the dot test then it would be approved as dot. But it will curdle into something smelly and not pass. Part of the test is 100 centigrade and 85000 cycles at 1000 cycles an hour. Also he was explaining about Dexron and that GM had loads of problems which mirror the RR363 problem. Dexron ( not dextron) was made from whale oil. When Wales got banned from selling their oil. GM made dexron 2 . Which was backward compatible. This gave a rougher shift so eventually to get shift quality back they changed the friction material in the gear box which got very confusing. The result of the brake dot bit is that dot4 is has better anti corrosion and lubrication additives and modern rubber brake hoses have Teflon liners ( maybe). He worked for Toyota for a bit and one technical boss was demanding that only dot 3 to be used and another is saying only dot4. So it is not only RR owners getting caught up in fluid confusion. (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1031 Registered: 6-2009 |
Add to the mix that while DOT4 and DOT5.1 (both glycol based, it's DOT5 only that's silicone based) have higher dry boiling points, their wet boiling points often fall below that of DOT3 fluid. I've been saying for some years now that PTFE core hoses are a blessing whether you're running DOT glycol fluids or HSMO. It's chemically inert, won't react with either fluid, and creates a hose that has a virtually perpetual service life when the newer reinforcements and coatings are taken into account. Never having to replace all the hoses on a SY series car again is, to me, well worth the price differential over regular ones just for the extended life alone. You are absolutely correct about the DOT specs (and, for that matter, most fluid specs). They're about the performance characteristics of the given fluid, not the chemistry. That being said, from a practical standpoint manufacturers find "usual chemicals at the lowest cost" to achieve the spec and then all use those. Additives such as the ethoxylated propoxylated castor oil in RR363 are another issue of their own and so long as the final result performs as the spec states it should it will pass. It's interesting that the latest generation of Dexron, Dexron VI, is not *perfectly* backward compatible with all prior generations for power steering and manual transmission applications.  The same can be said for motor oil as well. The two "big" certifying bodies are the ILSAC and API. Their specs are very strict regarding what lubricating characteristics must be present to carry their respective ratings and "seals of approval." If it were possible to add sand in place of one of the myriad additives to achieve the lubricating performance that would be just fine. The fact that both state, unequivocally, that all motor oils for gasoline engines are completely backward compatible and the newer specs meet all prior specs and then some, I've long ago dismissed all the horror stories that circulate about the damage that using current motor oils in older engines will cause. Why people trust all the "friend of a friend" stories while doubting the statements of the world's certifying bodies is a mystery to me. Brian, who won't get into the parallel misinformation out there on coolants on this thread | ||
| Bob uk Unregistered guest Posted From: 94.197.122.85 |
Dot 5.1 should have been called dot 6 or dot 4.1 because there is 600 which is dot 5.1 and blue in colour. Just to add more fluid confusion dot 4 once wet has a lower wet boiling point than dot 3 and absorbs water slower. Which negates any advantage unless abs is fitted. To add more confusion castrol LMA is dot3/4 . Some are now labelling dot3/4 because the makers have given up trying to market the stuff at supermarkets as dot 4 . Most race stuff has no abs so they use dot 3 or dot4 LV. Because it has a high boil point. The wet is low but they change every race. It's polyethylene not polythene. That's for washing up bowls not brake fluid. And to finally confuse the average motorist the word fluid is used so they think fluid is different from oil and therefore automatic transmission fluid is the same as brake fluid. It usually only gets as far as the master cylinder. The seals last maybe an hour. I took one off a car and the seals were like sticky blobs of tar with holes in the middle. I wash it out with jizzer and soapy water and loads of black stuff came out. I don't worry about boil points to much because to get fluid to boil needs a lot of braking and I don't drive like that. I have seen loads of. cars with ten year old dot that still brake as new. They still need a dot change though. I think us RR owners worry to much about dot fluid. I still say change every two years though. Once dot has boiled the dot is degraded. In race applications the brakes are useless until the dot is changed. If modern rubber hoses do have Teflon liners then at least the inside won't get flaps of rubber acting like valves. The outside will still crack and the swaging go dangerously rusted but that's visible. The braided hoses have come down in price and are about 75% more. Plus one can heat shrink them to match RR colour code. Which is a bit blingy. I suppose that could be done to rubber hoses to keep oxygen away, under a car is dark so UV can't get them. Ford had protective plastic on some hoses. There's a firm near me that makes up hoses to pattern while you wait, everybody uses them. The made me two cunifer returns from acv for a fiver brass tube nuts as well. Brake pipe clips and even pressure gauges £7.50 plus any fittings. Fortunately for use in the UK apart from petrol car bits are quite reasonably priced. Which is why I don't bother looking too much at alternatives especially when the alternative is about the same price. Except flying spares who sell hoses half nuts at ten times what they cost from nut and bolt shops. Which is next door to the hose guy. So handy. (Message approved by david_gore) | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 898 Registered: 9-2004 |
To add more confusion castrol LMA is dot3/4 What about the Citroen etc 12yr+ synthetic LDS fluid. Anyone brave enough to do some testing with an Rolls or Bentley pre 2000 car. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1034 Registered: 6-2009 |
Bob uk wrote: To add more confusion castrol LMA is dot3/4. Some are now labelling dot3/4 because the makers have given up trying to market the stuff at supermarkets as dot 4. That doesn't seem to be an issue here in the US. There are tons of both DOT3 and DOT4 fluids on the shelves. A couple of these, like Castrol LMA, are dual spec-ed. I could have sworn that the last bottles of RR363 that I had were dual spec-ed, but probably not. And to finally confuse the average motorist the word fluid is used so they think fluid is different from oil and therefore automatic transmission fluid is the same as brake fluid. That's an entirely new one for my stories book. Perhaps it's a result of how stuff is displayed for marketing. In most auto parts or department stores here, transmission fluid and power steering fluid are either in a separate aisle or clearly separated from motor oil. Brake fluid of any kind does not usually show up in the same aisle with any of the above. I have seen loads of cars with ten year old dot that still brake as new. As have I. It is not conventional (and not just "for me") to regularly do brake fluid changes on most cars here. I changed the DOT4 in the Jag every two years, religiously, because that system had sensors that were notoriously finicky. As far as I know the 1996 Buick, 2001 GMC Sierra, and 2007 GMC Sierra that are currently part of the fleet are all still operating on their original brake fluid. Most mechanics here simply will not change brake fluid until or unless some repair to the system creates that necessity. They still need a dot change though. Why, if they're braking as new? In any US made car I've owned so far in my 35+ years of motoring brake fluid changes simply were not done. My father, a safety supervisor for the United States Postal Service (USPS) did not do them (and various other things, too), based on what was learned from the fleet maintenance on the USPS fleet. If it ain't broke, and ain't at all likely to break, don't fix it. I see more havoc resulting from the compulsion to "change it while I'm in there," for things that are not at all likely to ever need changing at all, than I care to recount. I think us RR owners worry to much about dot fluid. I wish I could concur with this, but I can't just based on what I've seen with my two cars, let alone what's been reported to me elsewhere. I've never understood why the RR reservoir caps include vent holes, which certainly do not help with the known hygroscopic nature of DOT3 brake fluid. I've never seen this setup on a single other brake reservoir in any car of any make. [I'm sure there are some, but they're clearly the exception, not the rule.] Given the weird messes that form in SY era brake/hydraulic reservoirs, and that the original filter screens seem to be very inclined to collapse and rupture, I've been following the once-every-two-year change interval religiously on these cars. Brian | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3062 Registered: 4-2003 |
When you are a passenger on an A380 or B777 for 18 hour flights as most of us are periodically these days, I am glad that aircraft maintenance people do not follow this thread. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1036 Registered: 6-2009 |
Yes, because aircraft and automobiles are so utterly similar when it comes to the results of a random part failure. My friend, the instructor in an aircraft maintenance program, does not follow the same ultra-stringent protocols for his cars (including the Jag that was mine) because it's simply not necessary. Brian, who doesn't believe these apples and oranges comparisons do anything to support your position | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3064 Registered: 4-2003 |
Want a ride in my taxi, Sir ? No way José. Really, could this forum not be a vehicle for recommending skimping on everything from safety to reliabiliy ? I have read recent bits sinking to the depths of saving $10 on a substitute fuel pump (yes, Pierburg pumps are available at $10 more than the unreliable and noisy alternatives suggested - alternatices which need extra fitting pieces and labour at $200/hour to fit) to saving maintenance costs by spurning mandatory service schedules. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1038 Registered: 6-2009 |
Richard, If reporting on what is pretty much standard practice in the country of my residence is offensive to you then write it off and never get in a car in the United States. You need only ask your friends here who are not RR or Bentley owners, "When was the last time you changed your brake fluid?," to find out that what I'm reporting simply is. Whether or not one wishes to follow a certain protocol or not is an intensely individual decision. Reporting on the existence of practices that differ from your own is not, contrary to your implication, a "recommendation." I have tired of your insistence that discussing anything that diverges from manufacturer recommendations, with the notable exceptions of those you espouse, is some sort of an invitation to disaster. It's gotten very, very old. It's also utterly false. Brian | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3065 Registered: 4-2003 |
Alrighz, call me Mr Old Fashioned, but most people do try to obey statutory rules. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1039 Registered: 6-2009 |
And statutory rules vary by jurisdiction. Also, none of what I was discussing dealt in any way with statutory rules, at least not directly. If it's illegal to do something in a given jurisdiction I would advise against doing it. If it is not illegal in another jurisdiction then a number of factors need to be considered by the individual in order to make their own decision. Pretending that one jurisdiction's statutory rules are inherently superior to that of another is fraught, to say the least. It is wisest to simply obey the laws where one lives. I presume if I, or you, or anyone were to propose doing something that's against the law where a given reader lives that this would rule out that option for said reader, immediately and without anyone having to say it. Brian | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 900 Registered: 9-2004 |
"If it's illegal to do something in a given jurisdiction I would advise against doing it. If it is not illegal in another jurisdiction then a number of factors need to be considered by the individual in order to make their own decision". Brake fluid change every two years apart from the first thee years of the cars life. In all the manufactures service schedules apart from Harley Davidson. To many accidents through confirmed brake failure due to lower boiling point of the water content within the fluid on downward mountain passes etc. Not to mention the hoses and calliper pistons etc failing. Kill folk and get sued if you are still alive. The illegal law does not have to apply to in brake failure cases as there are motor investigators who soon get to the cause. Brian who talks a load of crap instead of getting on with his cars real problems, cripes what faults you have!!!!!!!! | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1040 Registered: 6-2009 |
Patrick, You are, quite simply, incorrect on virtually every count. Brake fluid replacement is not mentioned, even once, in the Owner's Manual service schedules for: - 1989 Cadillac Sedan de Ville (nor in the Service Information Manual, which I also checked) - 1996 Buick Roadmaster Estate Wagon [the manual states, in fact, "You should add (or remove) brake fluid, as necessary, only when work is done on the hydraulic brake system.] - 2001 GMC Sierra 2500 HD I shan't bother with the 2007 GMC, the pattern's quite clear. I have no trouble sleeping at night for fear of brake failure. Decades of not routinely replacing brake fluid, because it's not specified as a regular maintenance item for most of my cars, has shown they can and do run "virtually forever" on the DOT3 they were born with. Since the answer to the question, "When did you last change your brake fluid?," is most likely to be "never," for virtually every car I drive or have been a passenger in for the past 52 years, I'd say there's a clear track record of safety and reliability sans fluid changes. For the cars that do specify it, I do change it. Your opinion regarding my faults is duly noted and summarily dismissed. Brian, who believes that educated readers can, and have, figured out who's not being factual | ||
| Mark Aldridge Prolific User Username: mark_aldridge Post Number: 150 Registered: 10-2008 |
Richard, from the research I have done in the UK Pierburg pumps are not available from any of the RR spares suppliers. Can you give me a link to your source , as I presume this is in Australia. Mark | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 901 Registered: 9-2004 |
"Patrick, You are, quite simply, incorrect on virtually every count." Brake fluid replacement is not mentioned, even once, in the Owner's Manual service schedules for:------------ Whos telling porkies then? Are you saying that Valvoline are. Quote "Valvoline / Products / Valvoline Professional Series / Brake System Service / Complete Brake Fluid Exchange Service MSDS Complete Brake Fluid Exchange Service Removes old, contaminated brake fluid from your brake system to help keep your brakes functioning properly and avoid costly repairs. Brake fluid absorbs moisture from the air over time, which leads to soft or sluggish brake response. This very moisture may also lead to corrosion which may cause premature failure of brake system components, which can cost over $1,000 to replace. Valvoline Professional Series (VPS) DOT 3 & 4 Brake Fluid helps extend the life of brake system components, which may exceed $1,000 in costs. Many vehicle manufacturers recommend this service evry 2 years or 24,000 miles for optimal safety. VPS Brake Fluid exceeds the U.S. Department of Transportation specifications for both DOT 3 & DOT 4 brake fluids." You must get on with your cars and do them the correct way. | ||
| Bob uk Unregistered guest Posted From: 94.197.122.79 |
All brake fluid regardless of type should be changed every two years. There are yother things that happen to oil besides water. My engine oil doesn't have water in it but has other nasties. Same with brake fluid. Copper content and ph levels can rot out a system. The additives wear out. Dot 3 is about £2 a litre in USA at that price one could change every year. When I worked for plod police cars would come in for tyres and I would change the dot while I got the wheels off. Even if it had been changed the week before. The government supply Lockheed dot in 4 gallon colapsable bladders in a thick cardboard box and special bottles to decant 1/4 litre at a time. Any fluid not used I throw away. If the bottle is has fluid left in it which someone else put in it, I throw the bottle away and use new bottle. Fixing what isn't broke doesn't apply to oil changes. Also castrol red rubber grease. Issued in tubes used to rebuild brake stuff then any left in the bin. Next brake job new tube. Because big cans get contaminated and mistakes get made. I have overhauled brakes tested the car ok and the boss has then spent all day checking the job. He had the boxes from the New parts and the old parts. Any thing wrong and it's up before the board begging forgiveness. Pat L is right a few accidents I have checked out showed both water and copper in brake dot. It difficult to definitively blame the dot but it didn't help. A common excuse from a driver is the brakes failed. So the government has to be certain that when emergency vehicles have accidents that the dot cannot be blamed. I have measured caliper temperatures and they really do get that hot. 250c on hard stops. Just to add to the fluid confusion Shimano brakes have a special fluid. Which is not dot or silicon. But synthetic mineral oil type stuff. What ever synthetic means I am not sure. Another brake system for pedal bikes is stuff called royal red blood. Which shimano say will damage their brakes. In mountain bike circles this is debated often. More fluid confusion. I stick with castrol because I understand their system, and they have lots of information. Put the legal bit to one side. Smashing a car up for the sake of a £2 worth of dot is madness. And one might get physically hurt. And even if no ones hurt its a real pain sorting recovery etc etc. The £2 saved won't even pay the cab fare. (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1041 Registered: 6-2009 |
Patrick, "Many" apparently doesn't include GM for the vehicles I mentioned. You quote the material from a fluid manufacturer, not a car manufacturer. Since change intervals are specified for motor oil and transmission fluid, and specifically omitted for both brake and power steering fluid (which is specifically noted as an add-only item) . . . No mechanic, anywhere, has ever asked me whether I've changed brake fluid, either, which speaks volumes too. I'm done with this particular conversation because I do know what conventional practice has been throughout my lifetime in the states I've lived in, all of which have annual safety inspections. Brake fluid replacement is not commonly done. Since I've been living through "not commonly done" for decades on my own cars and those of most friends and acquaintances I know, I will continue to use what is a proven and successful practice for me. I just asked my partner, who's significantly older than I, if he had ever changed the brake fluid on any of his vehicles. The answer, "no." As I've said about many things, each person has to do his or her homework and come to a decision they are comfortable with. And to Bob uk or anyone else who thinks this has anything to do with the cost of DOT brake fluid, it doesn't. I will stick with what's been working for me over my 36 years and untold hundreds of thousands of safely driven miles. Others should do the same, using whatever has worked for them. Brian | ||
| Bob uk Unregistered guest Posted From: 94.197.122.84 |
£2 for peace of mind every two years is a no brainer and I don't give a flying fig to any other view and there's whole load of others that agree. As I said I don't worry about my SY or jeep dot because it's a consumable item that is changed every two years. Peace of mind. Have you ever wondered as driving down the road that the oil level in the engine might below because in a hurry one has forgotten to check. It's a feeling that is not conductive to a pleasant time. Shall I stop and check or shall I carry on what's that noise is the car behind or is my oil level low. Is my oil light working, I had a blown stop bulb last week. I can't stand the stress. (Message approved by david_gore) | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3071 Registered: 4-2003 |
Of course you are correct, Bob. It's a shame that Desk Mechanics on Google Steroids seem to know better. | ||
| James Feller Grand Master Username: james_feller Post Number: 326 Registered: 5-2008 |
not seem...don't. We are all so "RIGHT" behind a keyboard aren't we Brian....lord your threads and waffle gets tiresome. Here's a suggestion for you rather than sitting down and composing another contrary response, trot out and change your brake fluid... lets keep things light a simple please. J | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 473 Registered: 5-2012 |
More abuse - this forum is becoming tiresome. |
