Chris59 Posted October 30, 2008 Report Share Posted October 30, 2008 Hi, I have a problem with my TR3 : I can't bleed the air from the brakes ! No leak (apparently ) , new rear pistons and stainless rear hose, very good calipers and master cylinder...... I have replace all the fluid when I have change the 2 leaking rear pistons (new), as the rear hose. The front are already stainless items. I can't try anymore as I am on holidays in south of France, but MUST solve this problem as soon as I will be back home, next week. My thought is that it may be an "air lock" in the "S" pipe between the fluid reservoir and the master cylinder, but I can't check now. Any similar experience ? Thanks in advance ! Cheers, Chris. Quote Link to post Share on other sites
vivdownunder Posted October 31, 2008 Report Share Posted October 31, 2008 Hi Chris, So it's a Girling front disc braked 3, and we'll take it that the reservoir is full so it can gravity feed the master cylinder. Check there's a small amount of free play between the pedal push rod and the master cylinder, to ensure the internal plunger returns fully to the end, thus allowing the m/c to replenish. Have someone press the brake pedal while you look into the reservoir. You should see some swirl or movement of the fluid. Bleed the furtherest corner from the m/c first, then the fronts in order of distance from the m/c. It can take quite a while for the fluid to come through. Top up the reservoir after each corner is bled. Back off the reservoir lid to make sure there's no pressure lock, but leave it on, as fluid can squirt back and wreck the nearby duco. The lid is ventilated, but something might have gone wrong. It could be that the restrictor valve has jammed. That's the hexagon thing sitting above the 5 way spreader on the chassis behind the right front wheel on a RHD car. To test the restrictor, jack up a front wheel and spin it, then have someone hit the brake pedal. However, if the lines are full of air, you mightn't get any front braking effect for that reason, rather than the restrictor being jammed. Also just check that the bleed vales on the new rear wheel cylinders are drilled correctly to allow the trapped air to escape, as I've heard of faulty bleed valves. If all else fails, you might need to get a mobile brake service van with a pressure bleeder to get the job done, particularly if you've got a power booster fitted. Regards, Viv. Quote Link to post Share on other sites
Richardtr3a Posted October 31, 2008 Report Share Posted October 31, 2008 If you do have the restrictor valve then remove it swiftly. Standard Triumph agents recommended removal and mine was taken out by them. In my case the brakes would lock on. Also I have had the master cylinder block the fluid inlet and it had to be cleaned up. Good luck.Richard Quote Link to post Share on other sites
Chris59 Posted October 31, 2008 Author Report Share Posted October 31, 2008 Thanks Viv and Richard, I will try this as sonn as i will be back home next week. I'll keep you informed of the results Cheers, Chris. Quote Link to post Share on other sites
Lord Flashart Posted October 31, 2008 Report Share Posted October 31, 2008 I used a Gunson's Easy Bleed and it makes it all very easy. It pressurises the system forcing the fluid through. Also makes it a one man job, rather than getting the wife to sit in the cold garage pushing the pedal!! Flash Quote Link to post Share on other sites
ianc Posted October 31, 2008 Report Share Posted October 31, 2008 Rather than remove the restrictor valve (which would leave a gap in the pipework which would have to be bridged somehow), take the valve out, dismantle it and discard its innards (so that you can see straight through the middle). Screw the two parts back together (with the sealing washer), then replace it in the circuit. A pressure bleed kit is a real boon to anyone undertaking this bleeding job single-handed! I purchased a kit which uses the pressure from a tyre (inflated to quite low pressure) to push fluid from a container into the reservoir to keep things topped up all the while. The cost of the kit was not great, but I had to make an adaptor for the TR4 master cylinder (instead of writing to the manufacturer for one) - I had a spare cover for the master cylinder, so modified that to suit. With this virtually constant pressure applied, the fluid and air exit quite rapidly, which surely helps eliminate air pockets. Ian Cornish Quote Link to post Share on other sites
Trevor S Posted October 31, 2008 Report Share Posted October 31, 2008 Chris, Can't offer any advice that's not already been given but you may be comforted to know that I have the same problem on a TR2 I have almost finished restoring. My 2 has been rebuilt with a 3a braking system for reasons I won't bore you with, but has all new pipework, master cyclinder, calipers and brake cylinders. The only old untested part is the restrictor valve. On attempting to bleed I cannot get the fluid level in the master cylinder reservoir to move down at all. On loosening the pipe union at the master cylinder end where it leads to the restrictor, fluid emerged from the thread, so fluid appers to have passed through the master cylinder itself. Prime suspect must be the restrictor valve but if it was jammed as Viv says they can, wouldn't there be resistance at the brake pedal caused by the fluid not being able to move through the restrictor? Perhaps Viv could comment. I still get no resistance at all at the pedal. I'm using silicone fluid, having used it for many years in my TR4 (also fitted with a restrictor valve) not that I suspect that it makes a great deal of difference. Any additional thoughts appreciated, which hopefully will benefit Chris too. Quote Link to post Share on other sites
Chris59 Posted November 1, 2008 Author Report Share Posted November 1, 2008 Thanks for your replies, Chaps ! Trevor, it seems that we haven't the same problem, but contributors here may help both of us, with no doubt . Some more details about my bleeding problem, that I have forget to say previously : - it is a RHD car, with no brake "booster", - the brake fluid goes out at each bleed screw when I open one of these, - the level always need to be toped up often in the master cylinder reservoir when I try to bleed the brakes, - I still have air in the system and the brake pedal go to the floor, which ever side, front or rear, I bleed first or last, instead of be more and more hard, - I have adjust the rear brakes, so less pedal travel should be necessary, - my wife was seek of pushing the pedal, as said by Lord Flash, but hopefully she will be ok to try again when back from holidays ! Cheers, Chris. Quote Link to post Share on other sites
stuart Posted November 1, 2008 Report Share Posted November 1, 2008 Chris, Can't offer any advice that's not already been given but you may be comforted to know that I have the same problem on a TR2 I have almost finished restoring. My 2 has been rebuilt with a 3a braking system for reasons I won't bore you with, but has all new pipework, master cyclinder, calipers and brake cylinders. The only old untested part is the restrictor valve. On attempting to bleed I cannot get the fluid level in the master cylinder reservoir to move down at all. On loosening the pipe union at the master cylinder end where it leads to the restrictor, fluid emerged from the thread, so fluid appers to have passed through the master cylinder itself. Prime suspect must be the restrictor valve but if it was jammed as Viv says they can, wouldn't there be resistance at the brake pedal caused by the fluid not being able to move through the restrictor? Perhaps Viv could comment. I still get no resistance at all at the pedal. I'm using silicone fluid, having used it for many years in my TR4 (also fitted with a restrictor valve) not that I suspect that it makes a great deal of difference. Any additional thoughts appreciated, which hopefully will benefit Chris too. Trevor did you check the seals in the master cylinder as I have known NOS ones to have stuck in position and on using for the first time they take the edge off the seal. Also some of the repro rubber kits arent silicon compatable. New masters or ones that have been stripped right out sometimes need to be bled at the exit pipe before they will deliver any fluid to the lines. Stuart. Quote Link to post Share on other sites
Don Elliott Posted November 1, 2008 Report Share Posted November 1, 2008 I recently lost most pedal power for the clutch on my 1958 TR3A. I took apart the master cylinder for the clutch and the helical spring was in pieces. Also the off-center "key-hole" that you find on that little "top-hat" that holds it all together and centralized had become a round circle and there was no fluid pressure, unless I pumped the clutch pedal several times. I replaced the spring with a new one and found that I happened to have one of those "top-hats" in my spares bin. Check your master cylinder inside to see if this might be of help to your problem. BTW I still have the original restrictor valve in my TR and never felt the need to remove it. Quote Link to post Share on other sites
Paul Down Posted November 2, 2008 Report Share Posted November 2, 2008 Chris, Others, much more knowledgable have given specific advice regarding potential 3A brake problems. Having owned numerous vehicles over the years I have tried many different methods for bleeding brakes including the Easi-bleed referred to. I found the device messy and a bit of a pain in having to deflate a tyre to operate it. Having unsuccessfully tried to bleed an old Land-Rover I invested in the device illustrated here: http://bertram-hill.co.uk/toolsandtips.aspx This simply connects to your bleed nipples and through its vacuum simply sucks the fluid and any air through the system. It has always bled any vehicle first time. I believe there is a fundamental problem with devices that push air into the braking system in that if the fluid seal is broken only momentarily you will then get air into the system. The fluid drainer can also be used to drain those Diffs and gearboxs without drain plugs, very common now on moderns. Quote Link to post Share on other sites
BrianC Posted November 3, 2008 Report Share Posted November 3, 2008 Paul, I agree with your comments regarding the potential mess using the Eezibleed which is why I only used mine a couple of times. Your alternative looks interesting but is presumably not suitable for one-man bleeding, as the master cylinder still requires manual topping up. I haven't done this nauseating job for many years but have used a Vizibleed (one-way valve on a piece of rubber tube) quite successfully. However, perceived wisdom is that if you modify a spare master cylinder cap by fitting a bleed nipple, then the Eezibleed is considerably more reliable than the strap-on cap supplied with mine. Quote Link to post Share on other sites
Paul Down Posted November 3, 2008 Report Share Posted November 3, 2008 I agree with your comments regarding the potential mess using the Eezibleed which is why I only used mine a couple of times. Your alternative looks interesting but is presumably not suitable for one-man bleeding, as the master cylinder still requires manual topping up. Brian, You depressurise the device by a few pumps of the handle, connect to the brake nipple and you can control the rate of fluid withdrawn via the tap, plenty of time to keep on eye on the reservoir level. I always do mine single handed. There is an auto top up device with the device but I have always found it a pain to use and prefer to top up manually. I haven't done this nauseating job for many years but have used a Vizibleed (one-way valve on a piece of rubber tube) quite successfully. However, perceived wisdom is that if you modify a spare master cylinder cap by fitting a bleed nipple, then the Eezibleed is considerably more reliable than the strap-on cap supplied with mine. Yes, that seems a much better arrangement I always had a problem sealing the caps efficiently Paul Quote Link to post Share on other sites
vivdownunder Posted November 3, 2008 Report Share Posted November 3, 2008 Hi Trevor S, If the restrictor valve jams, then nothing can pass through it, so you have air trapped between the restrictor and the master cylinder, and thus no pedal pressure. The parts in the restrictor valve are steel, which rusts over the years due to water absorbed by the brake fluid. I just dismantle the restrictor and use a brass wire brush that won't scratch, to clean up the components, then wash them in metho. It's vital to record which way the various parts come out so they can be re-asembled correctly. Don has a drawing he made showing the sequence. Once cleaned properly, the restrictor can be returned to the car, and I've never had one give any further trouble. Chris, I was asked to assist locally with problem brakes some years back, and found the far end valve seal in the master cylinder had been fitted back the front. I seem to recall the owner couldn't bleed the brakes on that car either. Also, it's essential when reconditioning a master cylinder to put a small amount of brake fluid inside the bore ahead of each seal to lube it. I've seen them re-assembled dry, and the critical lip of a seal was damaged and failed. My preference is to use the traditional DOT 4 brake fluid and change it every three years. Owners have reported success with silicone fluid, but others have had a great deal of trouble with it in older cars. Silicone tends to enlarge the rubber seals which locks brakes, and has a slower refresh time, but has the advantage of not taking in water, nor damaging duco. It's certainly risky to just change over from DOT 4 to silicone without first renewing all the rubber seals and flexible brake lines. Regards, Viv. Quote Link to post Share on other sites
Chris59 Posted November 3, 2008 Author Report Share Posted November 3, 2008 Hello dear fellows from all around the world , and thanks again for your help. One more detail about my TR3 brake bleeding problem : I drove her from England to France without any problems, and the brake worked well, untill I decide to check every "nuts and bolts" of the car before the french MOT. I have replaced the rear flexible hose because it was a poor old rubber thing, with a brand new stainless steel one, as already used at the front, and the rear wheel cylinders because one was leaking and the other was size solid. So what's happen, I don't know, but it's a consequence of the replacement of these parts and of the "gravity" bleeding of the system, as one week last between the dismantle of the old components and reassembly with the new ones. Hope you undertand my English, it's far form perfect .... Cheers, Chris. Quote Link to post Share on other sites
johnny250 Posted November 3, 2008 Report Share Posted November 3, 2008 (edited) The method that I have used when filling and bleeding the brakes (new system) takes a bit of time but works well with silicon fluid that can be slow to dispel trapped air. Crack open the bleed valve on the furthest wheel, and attach a long piece of clear plastic tubing to the nipple. Hang it up with the end open to atmosphere and higher than the master cyclinder. Keep master topped up of course, then leave until bubble free fluid can be seen in the tube.....overnight helps, and without pumping the pedal. Close off and repeat for other wheels. john Edited November 3, 2008 by johnny250 Quote Link to post Share on other sites
Guest colinTR2 Posted November 5, 2008 Report Share Posted November 5, 2008 Hi I remember having this problem when filling a dry system on my TR2 after the rebuild. I finally resorted to the Eazybleed and all was fine. I suspected the rather tortuous brake line bend behind the master cylinder was trapping air. I used silicon fluid which has been in the system ever since, now 15 years or so, but with the occasional partial bleed for servicing, etc. I am sure that pressurising the system pushed the air through. The eazybleed can be messy, I have sometimes cut a rubber seal to go into the cylinder cap. best of luck Colin Quote Link to post Share on other sites
Chris59 Posted November 6, 2008 Author Report Share Posted November 6, 2008 Problem (seems to be) solved ! I have spend 2 hours this morning, checking every union, every pipe, flexibles, etc, for leak, trying to bleed the pipe between the fluid reservoir and master-cylinder, ...... I didn't touch the restrictor valve, as it is missing on this South African TR3 . My friend (haven't ask a second time to my wife ) help me and press, depress, press, depress the pedal, until his leg look like Lance Armstrong' legs, as I was on my knees in the wheel arches of this damn little beast , trying to bleed her again, and again...... And it didn't work at all ! This afternoon, I was alone, without my brand new easybleed bought 15 years ago and lost but never used, so I tried the simpliest way : gravity bleed, as suggested by Johnny250. The only alteration was to put the free end of the tube in a small can on the floor, and it work perfectly this time, the pedal is now hard ! I haven't find any "good" reason to my problem, but air locked somewhere in the brakes pipes ..... Thanks again for your help, Cheers, Chris. Quote Link to post Share on other sites
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