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MG TD TF 1500 Move to DOT 5 BBS discussion at MG-Cars.net
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MG TD TF 1500 - Move to DOT 5
| One wheel cylinder had started to leak, the rubber hoses were at least 12 years old, same as the brake fluid.
I was undecided between a singular repair of the wheel cylinder/brake shoes and an all round replacement. With the idea to convert to DOT 5, the answer was clear. Everything except the metal pipes had to be replaced. With an all round package, the total cost of the material was 300 € including brake shoes for both axles. Not too bad. + 35 for a liter of DOT5 fluid. So I spent a full day under the supervision of an experienced guy and replaced all the bits. Not an easy job, but could be completed in a long day. Pipes were cleaned with pressurised air until nothing came out. After two weeks, there are still minor leaks in places, but nothing serious. I keep tightening the screws in those places, hoping to reduce to zero. Brake feels fine, solid reaction, no pumping, can get wheels to block (for test purposes only). So far I´m happy with the result. Let´s see what the long term experience will be Best Regards Mike |
| Mike Fritsch |
| When I rebuilt my 51 TD I switched to DOT 5. I flushed the system with alcohol. I installed new rubber but left the copper lines in place. I had installed new wheel cylinders and ran them with DOT 3 for a short while but left them in place while flushing the system. That was two years ago and no problems since. I'm happy with the results. Tim TD12524 TD26711 |
| Timothy Burchfield |
| Sounds good, Tim. There's a lot in the archives about the difficulties to get it leak free, but I'm hoping for the best. Rgds Mike |
| Mike Fritsch |
| I drive DOT 5 since 2 years. No problems. Regards Klaus |
| Klaus Harthof |
| I have had DOT 5 for three years without any problems. Jim |
| James Neel |
| If anyone still has lines of copper they should be changed for safety’s sake. Regards, Tom |
| tm peterson |
| Tom, could you expand on why copper lines should be changed? Tim |
| Timothy Burchfield |
| Unless you're racing, what's the benefit of switching to DOT 5? Gord Clark Rockburn, Qué. |
| Gord Clark |
| Tim copper cold works over time and is prone to fracture and so is banned here in Australia. Steel bundy, the most common brake line pipe, is prone to rusting from the inside out, particularly when the vehicles are infrequently used and fluid sits in the lines absorbing moisture. The state of the art brake line material is Cunifer a copper, nickel, ferrous alloy, hence the name. Used in all the most expensive marques these days. Almost as easy to work as copper but without the downside. The benefit of Dot 5 is that it's not hygroscopic - it doesn't absorb moisture and so doesn't promote rusting. Cheers
Peter TD 5801 |
| P Hehir |
| The biggest advantage of DOT5 is that it won't eat the paint off your car when it leaks or spills. It also has a higher boiling point than DOT 4. True it won't absorb moisture but moisture can still get into the system and will find the low spots. These areas can rust, and if close to the brakes it can boil and cause pressure loss. For this reason it is still necessary to bleed the system at regular intervals, especially in wet climates. Since the master cylinder is vented to atmosphere and located underneath he car, T-Types are perhaps more susceptible to accumulating water than later MGs. It's for this reason I use DOT5 in cars with the MC located up high, and DOT4 in cars with the MC beneath the car. The DOT4 will absorb water, making it easier to vacate it during bleeding. But either will work fine with a reasonable level of maintenance.
Personally I would have used more than just compressed air to clean out the hard lines. You really don't want any trace of glycol fluid in the system when you change to Silicon. |
| Steve Simmons |
| We've been using copper in classics for as long as I can remember (a long time) and I've never heard of an issue with it. The best solvent for flushing out brake lines is acetone, because unlike alcohol it leaves no residual moisture. Dave H |
| Dave Hill |
| I cleaned my system with alcohol followed up by flushing it with DOT 5. Expensive but I wanted to be sure that I started with clean lines and components. Tim |
| Timothy Burchfield |
| Agree with you about the paint stripper and the boiling point Steve as other advantages. As stated one of the great benefits of Cunifer is that it is impervious to rust. The National Code of Practice here in Oz has banned copper brake lines. This is specified in Vehicle Standards Bulletin 14 Section LG Brakes para 2.4. Although not mentioned in the Standard the reason given was the possibility of fatigue stress caused by cold working. Cheers Peter TD 5801 |
| P Hehir |
| Peter, were classic cars exempt from the ban on copper lines? Could you replace the line's on your TD with copper? Cheers Tim |
| Timothy Burchfield |
| since 10 Years I use DOT5 without any Problems. I never change the fluid since that time. I change also to Cunifer pipes and stainless steel braiding hoses. I installed bronze Liner in brake cylinder and change all rubber parts in the brake system. I did the job myself, see Picture. I also modify the main Brake cylinder by a stainless steel liner. This job was done from White Post Team.  |
| GK Guenter |
| I think it's important to list miles and weather conditions rather than time when we're talking about how long something has been on a classic car. Some people only drive a few hundred miles per year and only on sunny days, while others drive many thousands through all kinds of weather. My daily driver is a '67 MGB GT which has been running DOT5 since the previous owner converted it in the 1980's, and if it matters it also runs Cunifer lines. No issues ever, after probably 150,000 miles. |
| Steve Simmons |
| I believe that up until a few years ago copper was acceptable here Tim. In fact I purchased a quantity of copper line and installed it. About a year later I discovered that I wouldn't be able to register the car unless I swapped it out. Wasn't a total loss though as I learned how to double flare. Cheers Peter TD 5801 |
| P Hehir |
| I often wonder why modern cars still use glycol based fluid. It is annoying to change it every couple of years and is bad for paint work.
I changed to Silicon Dot 5 in my road TC in January 1983 and my race TC probably about the same time or earlier. (I can't find the latter in my records.) It has given no trouble in either car. The only down side is that if there is a spot which might leak, silicon will find it! I dissembled everything and used water from the hose to flush the pipes because it mixes with glycol so well. I followed this with compressed air, methylated spirits (which also mixes well with glycol and water) and more compressed air. Bob |
| R L Schapel |
| The reason why DOT5 isn't used in modern vehicles is that it's incompatible with anti-lock braking systems. Not a problem in our cars, obviously. |
| Steve Simmons |
| Ah Thanks Steve. That explains it! I guess that means it is incompatible with some types of traction control too?
I used traction control in my TC race car for a while …. YES REALLY! At Collingrove Hillclimb there is a tight left-hander where I had to feather the throttle because my inside wheel would spin furiously. So I tightened the left hand brake cable and loosened the right. Then I could keep full throttle and prevented excess wheelspin of the left wheel with the handbrake. Worked well but it did make it very busy in the driver's seat. The things we try in ordr to improve our times!! Cheers, Bob |
| R L Schapel |
| Fantastic! I love old school ingenuity. |
| Steve Simmons |
| After we did our tour to "traversee de Paris", 1300km travel back and forth and the traversee itself, I am positively happy with the DOT5. Solid brake point, no fading on some of the quite hilly roads and all in 30-35 degrees C (90-100F) conditions. No issues at all. There is some residual moisture on some of the joints, but I keep tightening where possible. Best Regards Mike |
| Mike Fritsch |
| Switched the MGB over to dot 5 in 1979. No issues. Switched the TC over in 1984. No issues. Switched the Triumph over in 1985. No issues. Switched the TF over in 1988, no issues. Acquired the TD in 2001, brakes were seizing and excessive corrosion in 2004. Switched to Dot 5 during the restoration and no issues since going back on the road in 2008. I've been using dot 5 for decades with no issues. |
| D. Sander |
| Ok, I am going to ask a question that I am unsure of. I thought my brake lines were copper with metal plating on them, but when I checked them with a magnet, they are steel (or at least a magnetic metal) Do we have definitive information that the TD has copper brake lines? |
| Bruce Cunha |
| Bruce earlier M.G.'s had copper lines but my guess is that TD's used steel bundy as this was/is the most common and cheapest brake line material. The Brits were looking to keep costs down after the war and materials were scarce and expensive. Copper would probably have been an early casualty following the war. This is theory mind, not fact. Cheers Peter TD 5801 |
| P Hehir |
This thread was discussed between 16/07/2018 and 27/07/2018
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