| Author | Message | ||
     John Beech Prolific User Username: jbeech Post Number: 218 Registered: 10-2016 |
Before I begin, let me assure you I've not been smoking crack (nor funny cigarettes, Omar). After driving Tootsie and shutting her off, turning the key to the start position results in between 7-12 strokes for the left light to come on and between 17-22 strokes for the right-hand light to come on (she's SRX6816, a left hand drive American-delivery 1969 model). Based on these results, I judge I need to recharge her accumulators (said judgement aided in part by having receipts for extensive brake work ca 2010, which included new hoses, calipers, plus accumulators). Thus, I set about gathering the bits and pieces (hoses, nitrogen bottle, suitable regulator, etc. per Brian's superb details). Before I get around to doing the job, I drive her to my neighbor's house (about 600' away) where I leave her idling while we chat because I was anticipating 1-2 minute delay. However, the chin wag turns into 15-20 and as I approach Tootsie, she smells 'hot'. This doesn't make sense because it's mid-December where in FL it's in the mid-50s (Fahrenheit). And as some may recall, her water temp gauge doesn't seem to be working so I don't have visual feedback (I've since verified her thermostat opens fine using a IR temperature gun). Anyway, I'm not really concerned she's overheating and hop in to return home. However, at the end of his driveway, when I apply brakes, the car barely slows and my recollection is the pedal went to the floor. It all happened very quickly because I only applied brakes at the last moment since I was maybe going 5 mph, and fortunately there was no traffic because I'm out in the street before you know it. Yikes! Researching the issue of the pedal going to the floor, it seems the issue lies with the 5/8" bore master cylinder within the rat box. Per Paul Yorke I purchase one with 3/4" bore. Oh, and before I forget to mention it, I had also purchased a 2-post lift. Friends came over and we install it but before I could subsequently wire it up, I hurt my back severely. So this is the situation. My back hurts too badly to work on the car and the lift is out of commission until I wire it and my back hurts to badly to tackle the job. Grrrr. Meanwhile, I've been starting Tootsie regularly and letting her warm up about 10-15 minutes because I fear driving her. So yesterday, my daughter's visiting and asks about the new acquisition. We hop in and I happily show her how easily Tootsie starts and idles. Some vroom-vroom is followed by her party trick (where I shut off her engine and pump the brakes as she makes like a camel and drops her nose). Then I restart her engine and point out how the nose rises to level once again (as I explain the hydraulic nature of some of the suspension). Making the appropriate oohs-and-aah noises my daughter has learned please me when talking about my cars, she then asks about the various gauges and lights on the dash. That's when I realize the two red lights haven't come on. Hmmmm. Folks, here's the point of this ramble . . . Tootsie's left hand light now comes on around 30-32-strokes. And the right hand light at between 30-35 strokes. Oh, and the brake pedal? It feels fine. I'm tempted to go for a drive. What in hell is going on? Mechanical things don't heal by themselves. Here's what I posit. Leaving the car idling for 15 minutes led to a slow loss of brake pressure because of how low the engine idles (maybe 500RPM?). Thus, when I applied brakes . . . nah, this doesn't make sense to me. Folks, I am baffled but the business with the lights coming on after about 30 strokes is repeatable and the pedal feels firm. Thoughts? | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1645 Registered: 5-2012 |
Hi John My money is on reduced hydraulic pump efficiency. This can be caused by wear in the bores of the pumps or wear on the cam lobes that drive them (maybe they need re-shimming). You say after some "vroom-vroom" everything seems ok, with 30-35 strokes before the lights come on. This not only takes suspicion away from the accumulators, it also indicates the ACV's are ok. My guess is at tickover there is just not enough pressure being created by the pumps. Revving the engine runs the pumps faster and creates pressure. My next move would be to get hold of Brian's article on building a (low cost) pressure gauge, hook it up and see what's going on in there, particularly at tickover. Geoff | ||
| John Beech Prolific User Username: jbeech Post Number: 219 Registered: 10-2016 |
The low cost ship has already sailed because I already bought this nitrogen bottle and regulator from a pawn shop for $150.  - 600 psig regulator with small nitrogen bottle However, this one only regulates to about 600 psi so I bought another one (where the 1000 psi is comfortably within the regulated range). This one (below) is new and cost a bit more than $300, maybe $320. Then I had this hose set made up by Amazon Hose (local to me). And if you look closely you'll see I paid extra for quick disconnects (and the hose is 10,000 psi rated and plenty long, maybe 15'). Oh, and this includes a test gauge set up (with a quick disconnect as well). The latter includes a dump valve (so I can readily bleed the air). Anyway, I don't recall exactly how much I spent (probably blocked it out) but it may have been on the order of another $300 (on top of the new regulator plus the original bottle w/regulator), so call it close to 1RRU for everything (1RRU = $1,000 or one RR unit of money).  - 3000 psig regulator plus test-gauge set up Thing is, until I get the lift wired and my back healed, I'm stuck being unable to work on the car because, a) I don't fit beneath the car, and b) my getting down to the floor and back up right now would probably kill me. In fact, even minor exertion kills me. For example, last Friday I installed a new pool pump. Simple job because there's a mechanical standard so it merely involved R&R plus three new ring-terminals on the wires. New pump only weighs about 45 lbs, but I've been in agony since. I do, however, have hope because on Tuesday I am going in to a pain clinic for the first in a series of epidural injections (my understanding is its some kind of steroid). Anyway, these go into the lumbar region of my spine. Supposed to be a total of three visits to the clinic - at an out of pocket cost of about 1RRU each time because of the shitty situation we have in America with our health care. Shitty being defined by me as; I pay 1.5TRRU/month for 'insurance' but have a 6RRU/year deductible and thus, I fork over 24RRU/year 'before' I get any economic benefit whatsoever (1.5RRU x 12 month/year + 6RRU). And this (if you're out of the loop and don't know how fucked up the system is in America) has been set up by bleeding heart liberals in conjunction with the rat bastard health care providers expressly so that poor people (who weren't denied health care in the first place because they'd go to the emergency room of a hospital where by law they can't be turned away) to really screw them. Basically, now the poor don't pay for their health insurance (or pay very little) because the cost of their policies are paid by those who do pay taxes. Thing is, said insurance for the poor is one which they can't afford to use (because of the high cost of the yearly deductible). Like I said, it's a really shitty system created by Democrats for the benefit of the insurance companies, and it's so totally fucked up the Republicans rode the pony to power and and they now (I fear) are about to really screw the pooch (e.g. make things worse - as if). But I digress. Grrr! | ||
| Omar M. Shams Grand Master Username: omar Post Number: 1130 Registered: 4-2009 |
My Dear John, Your car will have the likes of me slightly unsure of our responses because of your front height control system being active. You may have issues with your hydraulic pressures being low. This could either be caused by the pumps not delivering or that the pressure is being diverted to the wrong place. I dont want to throw you by suggesting the wrong solution so I would suggest someone like Paul Y or David G or Gordon to give you the correct answers you need. Omar | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 411 Registered: 10-2008 |
John, I have had the accumulator pressure control valves play up when the engine bay is hot. Solution was to rebuild them. Mark | ||
| Patrick Ryan Grand Master Username: patrick_r Post Number: 1237 Registered: 4-2016 |
I am watching this with interest gents. I think Geoff is on the right path here regarding suspension hydraulics as well. The system is busy filling this (very slow in drive the book states, very quick in neutral or park?) maybe suspension is getting all the attention. However it does seem the system bleeds out of pressure during your inactive times, and not enough time allowed to completely fill both systems. However the pedal to the floor, would be another issue I feel. You say your recollection is it went to the floor, did it? Or did it just feel that way as you pushed harder to stop forward motion? All of the above, should have resulted in lights and buzzers going off. Do all of your lights, and buzzers work when the test button is pushed John? Smelling "hot" is another concern here. Did you open the bonnet and feel if anything was hot John? I hope your back gets better mate, there is nothing worse than a bad back. | ||
| David Gore Moderator Username: david_gore Post Number: 2465 Registered: 4-2003 |
Pedal to the floor...... my suspicions would be air in the low-pressure 3rd brake circuit. The master cylinder is there to provide brake feel and a modicum of additional braking influence at the caliper. The variation in pump down results suggest either worn brake pumps as suggested by Geoff or faulty ACV valves as suggested by Mark | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 1329 Registered: 5-2015 |
before doing anything else fit a 0-3000 psi gauge to the bleed port of the ACV. Refer to fault finding flow chart in workshop manual | ||
| John Beech Prolific User Username: jbeech Post Number: 220 Registered: 10-2016 |
And we're back to my needing to wire the lift before I can raise her up and perform the work and my back keeping me from doing it. Looks like I'll be waiting until after the injections give me some positive results before giving it a go. Heavy sigh! Anyway, I will continue to monitor this thread closely in hopes some consensus develops. | ||
| ross kowalski Grand Master Username: cdfpw Post Number: 326 Registered: 11-2015 |
John, Do you need a high pressure gauge? I have a big ( read accurate) 5K unit you can have if you want. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1752 Registered: 6-2006 |
Unfortunately everything will involve getting under the car. I hope the injections help. Here's a possibility. . . The brake pedal should never reach the floor. You can try pressing it hard with a master cylinder nipple open. When you press the brake pedal the linkages first press the master cylinder in. The master cylinder gives the brake linkages a 'stop' at their lowest point. After which pressing further allows the ' trample ' ( for want of a better word ) to the move forward pressing the two brake actuator valves. Poor master cylinder or air allows too long brake travel. If the master cylinder fails there is nothing for the levers to react against. SO the design includes an emergency stop which will not allow the linkages to bottom out BEFORE the pedal hits the floor. This stop is a Metalastic sandwich which can fail or be missing giving nothing for the linkages to react against and the pedal will reach the floor before operating the actuator valves. Later cars have a solid metal stop. (And a rubber stop for feel instead of the master cylinder). Early cars had a warning light switch that came on when the master cylinder travel was excessive. Hot whilst ticking over. . Possibly a lazy viscous? DO NOT BE TEMPTED TO DRIVE IT UNTIL THE CAUSE of the brake failure HAS BEEN ESTABLISHED. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1753 Registered: 6-2006 |
Can I mention at the risk of being very unpopular on here. There is always the danger of DIY fixation. There is no shame in buying reconditioned parts or even getting somebody to fit them for you. There have been a number of threads where people have spent years trying to sort out their own accumulator and valves - going on time consuming and often reckless and expensive exploits along the way. Totting up time and cost I figure it would have been cheaper to fly me out with the parts in my luggage to do the job. There will always be plenty more jobs to be done and at least one can use and enjoy the car in the mean time instead of it being stuck in the garage with a black cloud over your head. Just food for thought and I'm ready for the fall out. :D | ||
| David Gore Moderator Username: david_gore Post Number: 2469 Registered: 4-2003 |
Paul, No fall-out from me just complete agreement - for critical safety systems such as brakes, these should only be repaired/overhauled by DIY owners who have sound mechanical knowledge and skills to be able to strip, overhaul and replace components competently and safely plus testing the finished work safely and thoroughly before the vehicle is driven on public roads. Know your limitations and work within them - Paul's comment below contains a lot of truth and should be kept in mind by those contemplating major DIY maintenance: "There have been a number of threads where people have spent years trying to sort out their own accumulator and valves - going on time consuming and often reckless and expensive exploits along the way. Totting up time and cost I figure it would have been cheaper to fly me out with the parts in my luggage to do the job" . | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 1330 Registered: 5-2015 |
Paul Yorke is bang on the money about diy fixation. I brought reconditioned spheres which have lasted over 20 years. They were £70 each. They are now £130 each. In 20 years time that will seem cheap. AS Dave said there have been cases where some have spent loads of money on rebuilding their own spheres to find they have small nitrogen leaks and the spheres discharge in a few months. When my spheres were replaced it took 4 hours and the car was back on the road. Not 4 months. Also although the car was designed to be taken apart the danger is that something gets damaged a long the way. | ||
| John Beech Prolific User Username: jbeech Post Number: 235 Registered: 10-2016 |
No temptation to drive it on the public roads at present - none. And hiring the work may be the ultimate resort because my back is still killing me. However, then I'll hire a flat bed truck to fetch it to my mechanic - no big deal. Anyway, no huhu on this end for the advice, believe me. | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 412 Registered: 10-2008 |
Paul, I am in total agreement with your comments. My son and I do 90% of our own work, but if special RR tools are required and there is no safe work around, or the job is particularly awkward, then the 35 mile drive to the RR specialist is worthwhile. FS now supply reconditioned assemblies, eg rear hubs which make DIY repair considerably easier. Mark | ||
| David Gore Moderator Username: david_gore Post Number: 2470 Registered: 4-2003 |
Back in the early 2000's when we holding the NSW Branch Self-Help Groups, I modified a joke doing the rounds at the time and it was published in the Branch magazine at that time. For the education of forum members, it is timely to re-publish the following: Subject: Why NSW Branch has a Self-Help Group Oil Change instructions for Women: Any day of the week: 1) Pull up at service centre when mileage reaches 10,000 kilometres since the last oil change. 2) Have a cup of coffee. 3) 15 minutes later pay and leave with a properly serviced vehicle. Money spent: Oil Change and Filter: $60.00 Coffee/Cake: $ 5.00 Total: $65.00 ************************************************************************************************************************ Oil Change instructions for Men: Saturday: 1) Drive to auto parts store and buy a container of oil, oil filter, kitty litter and hand cleaner. 2) Stop at liquor shop and buy a carton of beer before driving home. 3) Arrive home and open first beer for refreshment while planning work. 4) Spend 15 minutes looking for car stands. 5) Find car stands under kid's pedal car, retrieve them, jack car up and position safety stands. 6) Open fresh beer and ease tension. 7) Place drain pan under engine. 8) Look for spanner to fit sump drain plug. 9) Give up and use adjustable wrench instead. 10) Unscrew drain plug mutilating plug corners in process. 11) Drop drain plug in pan of hot oil splashing hot oil on face and arms in process. Swear profusely. 12) Crawl out from under car to wipe hot oil off face and arms. Throw kitty litter on spilled oil. 13) Have another beer while watching oil drain. 14) Spend 30 minutes looking for oil filter wrench. 15) Give up; crawl under car and hammer a screwdriver through oil filter body and twist off. 16) Crawl out from under car with oil filter splashing oil everywhere from holes. Cleverly hide old oil filter amongst rubbish in garbage bin to avoid contamination complaints from Council. Enjoy success with a beer. 17) Mate shows up; finish carton of beer with him. Decide to go and see his new home theatre setup and finish the oil change later. Sunday: 18) Skip planned family outing because "I have to finish the oil change." 19) Drag pan full of old oil out from underneath car. Cleverly dump oil in hole in back yard instead of taking it to the recycling centre. 20) Throw kitty litter on oil spilled during step 16. 21) Time for a beer. No, drank it all yesterday. 22) Walk to liquor shop; buy carton of beer. 23) Install new oil filter ensuring a thin coat of oil is applied to gasket surface. 24) Empty new container of oil into engine. 25) Remember drain plug from step 11. 26) Hurry to find drain pan to retrieve drain plug. 27) Find the drain pan in the yard where the used oil was buried. Realise with sinking feeling that you also buried the drain plug. 28) Ease disappointment with beer. 29) Shovel out hole and sift oily mud for drain plug. Find plug and dig-over oily patch of ground to hide contamination. Wash drain plug in petrol intended for lawnmower. 30) Discover that the fresh oil is now on the floor. Throw more kitty litter on oil spill. 31) Drink another beer to reduce stress levels. 32) Crawl under car getting kitty litter into eyes. Wipe eyes with oily rag used to clean drain plug. Misalign adjustable wrench whilst doing up drain plug and bang knuckles on sump when it slips. 33) Bang head on car body in reaction to step 32. 34) Begin prolonged swearing fit. 35) Throw away stupid adjustable wrench to ease frustration. 36) Swear for additional 5 minutes because wrench hits favourite garage wall pin-up poster damaging the poster beyond repair. 37) Soothe shattered nerves with a cold beer. 38) Use hand cleaner on hands and forehead to remove dirt and oil before bandaging as required to stop bleeding. 39) Seek pain relief with a beer. 40) Stronger pain relief required so consume another beer. 41) Fill sump with oil and check for leaks. 42) Celebrate impending completion of job with a beer. 43) Lift car to remove car stands and lower to ground. 44) Car accidentally crushes oil container left under car and spills remaining oil on floor. 45) Move car back to apply more kitty litter to spilt oil. 46) Enjoy beer while kitty litter does its job soaking up oil. 47) Take car for test drive. 48) Get pulled over by Highway Patrol car. Police officer refuses to accept explanation that regular movement of car from one side of the road to the other was a factory recommended test for oil surge. Officer extends invitation to visit local Police Station to stay overnight so Judge can hear explanation next morning. 49) Judge is as fixated as Police Officer and refuses to believe diagnostic procedure explanation. 50) Call loving wife to arrange payment of fine and court costs before returning to pick up car. 51) Find car on side of road with wheels missing and battery stolen. Money spent: Parts $ 45.00 Fine and Court Costs: $2500.00 New wheels and tyres: $2800.00 New Battery: $ 125.00 Beer: $ 90.00 Total: $5560.00 But at least you know the job was done properly! . | ||
| gordon le feuvre Prolific User Username: triumph Post Number: 176 Registered: 7-2012 |
John,a couple of thoughts. Has your car got viscous fan/ and cowl. Can't remember when these came in. Early cars suffered from air being drawn through rad escaping at sides of fan. Cowl made sure air was pulled through fan and therefore much more efficient. When master cylinder fails, as Paul Yorke says pedal will go nearly to floor. The linkage will then hit "on stop" In early cars it is metalastic affair, later ones a solid round bar that varied in diameter dependant on chassis no. During early seventies, the factory were always messing around to improve pedal feel/action. The master cylinder can fail because of internal seal issues or because brake fluid has cooked by either handbrake being left on or brakes sticking on. If m/cylinder fails, the on stop is necessary to then allow linkage to react to something solid, either resistance of pedal if m/cylinder working or on stop if not. This then allows pins to push into distribution valves to operate HP circuits. If you have then experienced loss of m/cylinder AND HP circuits, even though engine was running at low idle, my assumption is that the pressure you had drawn off HP circuits driving/braking is not being replaced. With engine at 1000 rpm. and bleed screw open the pump (either one) should produce flow of 250cc. The other issue I have found, is that even if pump working the internal valve in accumulator allows fluid to start to return to reservoir before it's reached required pressure, but on both systems?? It is my opinion, that the only way to correctly check operation of HP system is to obtain 0-3000psi gauge, depressurize system being worked on. Remove outlet HP pipe from accumulator and insert gauge in this port. This then isolates pressure control from rest of car. The gauge should flick up to 900-1000 psi on starting. This represents nitrogen pressure. 800ish is ok, but anything less is not as this pressure represents the safety stopping of car, should engine cut out. pressure should then build steadily to 2500-2600, then drop back to about 2200 when system settles. Crack bleed screw to represent brakes being operated. Once pressure has dropped to 1700-1800 pressure should start to build as internal valve directing fluid back to reservoir closes and directs fluid back to charging sphere. When system depressurised, I used to loosen jubilee clip on rubber low pressure return to reservoir hose and remove same off pipe. You need to keep thumb over end as fluid from reservoir will run out. You are observing for no fluid being returned to reservoir as pressure builds. When pressure reaches 1600-1700, it is wise to reconnect this pipe otherwise when valve shifts at 2500 fluid squirts EVERWHERE! You are observing fluid not returning to reservoir too early caused through internal leak in accumulator valve body. If it does, it has effect of pump "fighting" itself by returning fluid BEFORE sphere charged up. This would be aggravated by low pump performance/low engine speed. John, in summary, it is most unusual for all three circuits to fail at one time. Only real way is to check them all out. A lot is written about nitrogen/spheres, but they are only part of the equation. Sorry to have gone on a bit but it is a complex system and there is no easy test/fix. Of course the engine needs to run though all this testing. It gets very hot, making things difficult. So take care. Also ALWAYS remove gear change isolator before starting tests, it really is SO EASY to accidently knock gear selection lever (I have done it) when start/stopping engine, and gear selection does not take any prisoners!! | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1653 Registered: 5-2012 |
Nice write up Gordon. I'd just like to add that Brian produced an article on how to build a hydraulic pressure test gauge. It can be found here: https://drive.google.com/file/d/0B61gLtsXt4oqNUVydXYzVWt2Y3c/view He also points to an additional article by W Hunter: https://drive.google.com/file/d/0B61gLtsXt4oqaXV4THU2RjVCMDQ/view John - this would be a good time to fabricate your gauge - whilst you are waiting for your back to get better. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 1336 Registered: 5-2015 |
John Beech, When your back is better and you have fitted the 3/4 bore master cylinder just post on a new thread and I will explain how to set the push rod length and bleed. | ||
| John Beech Prolific User Username: jbeech Post Number: 261 Registered: 10-2016 |
I inadvertently hijacked the thread about fuel injection in response to a query by Christian regarding my plan to park Tootsie while I sorted out the brakes. This, in reference to my pedal goes to the floor event. I've asked David to clean that thread up. Meanwhile, I've copied my response here where it belongs . . . Funny thing that. The engine is idling a bit too low and if allowed to sit for an extended period of time (significantly longer than waiting at a traffic signal), then one of the red brake lamps 'may' illuminate. Happened again today - but only once and only because I am 'trying' to induce it (to verify exactly what happens). Today the brakes continued to work - though maybe not as good but it's hard to definitively say because I'm not making much headway, e.g. moving maybe 5 mph so it doesn't take much to bring it to a stop. And no, I haven't felt like going out and accelerating to 40 mph on a straight section of road and shutting the engine off to see if I have much/any brake reserve. This, because I suspect there's little (e.g. no need to go test what I'm pretty sure is the case). Anyway, the left-hand red brake lamp consistently illuminates between 7-12 strokes and the right light is consistently between 27-32 strokes. Oh, and the left-hand lamp is the one that has illuminated this second time (today). And no, I don't remember which illuminated the first time but I would wager it was the LH lamp that time as well. Since the brakes do not go to zero when the left light illuminates, I must have been mistaken last time - perhaps due to being startled. In any case, precisely because I was startled that first time, I have been exploring the envelope (yesterday and today). So today I managed to induced it to happen again, this time after idling about 10 minutes (note; I have the engine idling too low). How low? I haven't put the tachometer on it but I'd wager less than 500 rpm because it won't creep forward at all when slipped into drive but instead just sits - not quite on the verge of moving forward unless I goose it lightly. Of course, this means I'm not using Tootsie for transportation but am instead just fooling around on backwoods roads being very careful and keeping her exercised. . . . to which I'll add; yesterday I drove her down a straight piece of road at 40 mph and switched her engine off. She stopped perfectly and with no brake lamps illuminated. No, I didn't modulate the brakes but instead just applied them until I was stopped. As far as I am concerned this confirms I just need to top up the accumulators. Does anyone disagree? Meanwhile, also yesterday, I took Tootsie over to a fellow I know (retired RR mechanic who now runs a repair business out of his residence). That, along with hiring his four Clouds at Disney (for Princess Bride type wedding events where he dresses the part in a chauffeur's uniform) keeps him busy as busy as he'd like. Anyway, he drove Tootsie (with rather greater enthusiasm and verve than I have) and confirmed what David Gore said above, I need to bleed the brakes. He also did a lot of easing her in gear to feel for hanging calipers (all seems OK). He advised me to renew the brake fluid sooner rather than later (we've already discussed this in another post and I'm going to do so with YAK363). Finally, whilst driving he really buried his foot in her to gauge her acceleration and nailed the brakes hard. In fact, he drive her a LOT harder than I have, or will. One thing he noted is a slight miss in the engine. Said it felt like a spark plug. However, after I explained recently fitting Iridium plugs - without regapping them for points because I plan to install the Pertronix, which I have in hand - but haven't installed yet this due to my back, he said this was likely the proximate cause. He also advised ohming the wires. |
