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Triumph TR6 - Lots 'o' Leaks
|I'm finally putting the brake system back in after a restoration and I seem to have lots of small leaks in the system, mostly at the PDWA and MC. I'm afraid to tighten the connections down any more for fear of stripping them. Just wondering if you guys use teflon tape or something else to help get good connection seals. I have tried Girling brake grease but it doesn't seem to help much. BTW, this is the first full resto I have done, and after all of the trials and tribulations I have had with replacement of the braking system I would never even CONSIDER putting anything but silicone fluid in the system. If I had used DOT 4, I'd be one P.O.'d guy right about now. I know there have been many debates over performance, but from a handling perspective, there is simply no debate.|
|Most of the articles I've read about the proper flares on brake pipes have been about as clear as mud to me. I have sometimes had to tighten fittings more than I wished I had to. Flare wrenches will be much easier on your fittings, allowing more torque before rounding off the edges, and the ensuing language you'd rather not have the kids hear. (Almost as bad as the words that come out when your paint is a bubbly, sticky mess.)|
|I have used teflon tape with no ill effects, also I had a leak at the PDWA that turned out to be a very small washer under the top most fitting check this. At the Master I found a couple also but used tape and a strong hand on the wrench to success.|
|BTW I had a mechanic verbally undress me for using Silicone I dumped him, same reasoning as you while my car is not a diamond by any judge if I used dot 4 it would have been stripped to bare metal under the hood. My leaks were good for emptying the large reservoir(ie:front Brakes) overnight.|
|I'VE USED PURPLE SILICONE BRAKE AND clutch FLUID IN MY 1958 TR3A FOR 15 YEARS NOW WITH NO PROBLEMS. THAT'S MORE THAN 82,0000 MILES.|
Don Elliott, Original Owner, 1958 TR3A
|I must say that the best reason for using Dot5 is that Don has already done all the long-term testing. It is good to see you back at the keyboard, I hope the New Year will find you putting many miles on your TR3 when weather allows.|
I found the same leaks as you when I finished up the brakes. The only way I got it to stop was a flare
wrench and more tightening then I was comfortable with.
Dot 5 silicone all the way for 4 years now.
|Did you use the original lines or did you replace them? I found that the flare on my original lines at the PDWA were in pretty bad shape and decided to get replacements. One line Moss did not list, but was listed at Roadster. It was backorder on all the lines from Roadster, so I went and got the balance from Moss. Lo and behold, they had the wrong type of flare on them. The one I had placed on backorder from Raodster finally shipped and it had the correct flare.|
Since I still had the others around, I took the Roadster tube and all my old ones and had new ones, bent to match, made up with the correct flares and fittings. I am convinced that the only prayer of not having a leaker with the Moss tubes would have been to tighten them to within an inch-pound or so of their life.
|Been out of town, thanks for all the replies. The system I'm installing is a mix of old and new, but interestingly enough it's the new connectors that seem to be giving me the most trouble. All were purchased from TRF. I'm now inspired by your comments to take a much closer look at the flares. I'll also try the tape thing and torque 'em in tighter which, like all of you, scares the hell out of me.|
The really ironic part of all this is that when I bought the car (a '71) in '85 I bought a flaring kit and a bunch of straight pipe and fabricated many of the lines myself with no leakers. I decided this time around that life was too short and I'd buy everything pre-made. I'm now spending more time screwing around with it than it would have taken me to do them again myself!
|Hey, Jim. Don't bother with tape on the threads. These are metal to metal compression fittings so you're going to have to crunch down on them. The tape may provide some thread lube, but so will oil. It won't help for sealing - it just moves the leak to between the nut & tubing.|
Sometimes you can polish up a flare with Mothers compound (should be in every shop), but you're right, if it won't seal because the flare angles are different, don't screw around with it and make a new one up. Good luck.
|Jim - I made all my own pipes. I measured the old ones and went to a NAPA type store and bought what lengths and diameters I needed with the correct fitting on at least one end.|
This way, all my pipes are the same color of cad appearance because I chose to select them myself.
Then I cut off the rusty looking fitting for the other end from the old line I had removed. I had these fittings cad plated and I flared them onto the new lenghts after cutting them to the exact length.
This was in 1990. 82,000 miles ago. Never had a flare leak with silicone fluid.
|Every time I see a post from Don, it tells me more of the amount of love/care that he used while assembling TRusty.|
Teflon tape on the brakes doesn't sound smart to me.
Who's the flare expert out there? Is there some trick besides just making a nice double flare?
|Brent, after more thought, I agree with you. The tape is just a band-aid for the underlying problem. If the commpression fitting isn't right, it's just plain gonna leak. I've decide to go back through the whole sytem. The connections that seem OK, I'll leave alone, but if another few lb-feet of torque don't teach the problem children a lesson, I'll do it right, like Don recommends, and do it myself. Thanks to all for the input.|
|The flare on the pipes out out of my PDWA and MC were a bubble flare as were the flares on the one replacement MC to PDWA tube (the -3 tube with the oddball larger threaded fitting from Roadster, normally that thread size is used with -4 tube). The problem that I had was that one of the bubbles had been crushed to point that it took a gorilla effort to remove it from the PDWA, the other bubbles were as bad, but were a little too rough to polish up. |
I have double flare tools, but not anything that does bubble flares, so it was off to the tube shop or pony up the brass to get bubble flare equipment. There was the option of taking Don's approach, but I could have them made up and prebent for about the same money, making this a no-brainer which was a good thing because I need those on occasion. The balance of the tubes (calipers, wheel cylinders and such) in the system were all regular taper double flares.
Do remember that the TR6s with 16P and 16PB calipers use a unified/SAE threaded fitting while those fitted with the 16M calipers that have a metric fitting at the caliper. The Toyota four piston units also use a metric fitting at the caliper and have different bend configuration.
|I've discovered the basic problem here. Thought I'd post it in case others have the same experience. The pipes bought from TRF have nice looking bubble flares, but the flares receed too far into the connector; they're bottoming out before the flare is tight, or even snug, for that matter. The connector is tight, but the brake line still swings freely. I could crank on them as hard as I could and the flare would never be sufficiently tight against its mating surface. I have successfully resolved this by very carefully tapering the ends of the connectors with a very fine grinding stone (obviously taking great care not to make contact with the brake line)so the flares become more prominent. In every case where there was a leak it has stopped. I can now tighten the connectors finger tight and the lines are tight and won't swing. |
Only one leak left; it is coming out of the top of the PDWA sensor. I am assuming this means I need to replace the o-rings on the PDWA piston. Can anyone confirm this? Also anyone have a source for a replacement? I know I saw one somewhere in the archives but can't seem to find it. Thanks.
| Way to go, Jim. You are correct about the PDWA - there is no seal on the connector so it leaks there when the o-rings go bad. The size to use is 5/16" X 3/16" (or 5/16" OD, 1/16" thick). I used standard material - I think it was Buna-N. Nothing "exotic" like Viton - there's silicone BF in my system.|
|Thanks Brent. Went to Home Depot and bought 2 O-rings for a total of 66 cents. Solved the problem immediately. I wish everything on these cars were that simple.|
|I've recently purchased a TR6. What is a PDWA switch and do you need it? Can it be omitted and replaced with inline connectors? I've just rebuilt the servo and can't get the rear brakes working. All the brake lines seem to be solid!!Any ideas?|
|James, did your rear brakes function before you did the work? This would help in the diagnosis.|
This thread was discussed between 03/01/2005 and 18/01/2005
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