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MG TD TF 1500 - new brakes leak like a sieve!! Mayday, Mayday!
|Okay, I've followed every piece of advice and read the archives for days on end. I've installed my new Moss brake pipe set, cleaned female ends like new, bench blead the MC, screwed it all together without overtightening, poured in the Dot 5 and the new fittings leak all over the place! I keep pouring it in the MC and it's all over the floor especially around the 3-way fittings and at the MC itself. I even tried Gasoilia soft formula. It doesn't do anything! What next? Any ideas will be appreciated.|
|....a little tighter? I used the Moss kit and Dot 5 and tightened until they didn't leak, although, I didn't have horrendous leaks from the start...|
|I just found an old post from somebody who determined the new Moss pipes do NOT work with existing 3/4-way fittings! Somebody please tell me that is not true!!!??|
|If they don't work chances are the flares are not compatable. When I have had that problem I have tightened the fitting to reform the flare to whatever specs it had to be and then loosened and retightened to what ever seemed a reasonable torque.|
|I used the Moss brake pipes, original cleaned and polished fittings, and DOT5. I had several small leaks and carefully tightened the leaking fittings until they did not leak. It took a good number of passes and a couple of weeks before the last leak was stopped. You may be surprised how much you have to tighten some of the fittings.|
I have Gasoila, but did not want to run the risk of contamination, so did not use it for the brakes. (I do use Gasoila in some locations on the MG.)
I used a mix of new brake cylinders (rear, from Moss) and stainless steel resleeved brake cylinders (front and master cylinder). On reassembly of the cylinders I used a thin smear of silicone dielectric grease where the rubber parts meet metal.
I suspect you aren't using enough force when tightening the fittings. I can't tell you how much effort I used, but it was more than I initially thought would be required.
|Larry, I've got your notes which I've used EXTENSIVLY on this brake job! I just wanted you to know that. Without them I'd still be up a creek. I just pulled my new MC pipe and replaced it with the old one, cleaned up good. That leak went away!!! The old pipes are much more "rigid" that this new stuff. That I noticed immediatly. I also bore down on some of the other leaks and they went from flat out spurts to small drizzles and I'm actually getting breaking action at the shoes except for right rear which for some reason is not getting any fluid??!! Maybe Moss or somebody needs to check these kits out and advise us what should be done to use them with current unions? Tightening something up should not be rocket science, imho!|
Bob, the instructions are SPECIFIC about not overtightening but what else you gonna do? I'll give your idea a shot though. Tighten more, loosen, then tighten normal. Visually the flares look identical to me though.
I think the guy who devised this system must have been the same guy who designed the door latches!
Glad my notes are of some use. I'm certain the original brake lines were of a different material than the Moss replacements. That is not to say that the Moss brake pipes are bad. I was quite impressed with my Moss set.
You may be able to confirm operation of the rear cylinder by operating the emergency brake lever that is part of the cylinder. It sounds like there is air in the rear cylinder, so additional bleeding (not of you) may be in order
|Still not getting fluid from rear union to rear wheel. To test I removed RR pipe totally and ran air thru it from union side all way thru bleeder. Worked fine, not clogged, air comes out bleeder. I confirmed fluid comes out that union on right side by pumping brake. Worked fine, fluid all over the floor. I removed RR pipe from banjo & pumped brake. Still no fluid! I confirmed right E-brake works as it should. Cylinder acts normal & shoes move. When I put pipe back on, open RR bleeder and pump brakes still absolutly no fluid out of bleeder! I'm stumped??? Can you think of anything I'm missing?|
|Ed, it's usually something obvious but for some reason it gets missed. I'm thinking something in the assembly is wrong. I hope your cylinder isn't leaking in the drum.|
|Mike Hart (52 TD 16378)|
|I wonder if the rear cylinder is working properly, but lacks the throw to press the shoes against the drums. This is not uncommon. You may need to shim under the adjustment mask to cause the shoe to reach the drum. I can provide more details, if needed.|
I used new MOSS lines and they fit the 3/4 way brass fittings without leak or problem.
Have you set the shoe adjusters properly? I had leaks when I had too much slack there. Tighten them, then back off ONE click.
|"When I put pipe back on, open RR bleeder and pump brakes still absolutly no fluid out of bleeder! I'm stumped??? Can you think of anything I'm missing?"|
Let me come at this from a completely different direction. You should be able to trace this down in a stepwise manner. I assume brake fluid comes out of brake line on its way into RR banjo. if you tighten brake line to banjo and completely remove bleeder, I assume brake fluid comes out where bleeder connects to banjo. Finally, if you insert bleeder loosely in banjo, I assume brake fluid comes out bleeder. If you get this far you should be able to reasonably bleed the RR cylinder. If not, something is blocking the cylinder from filling with fluid.
Make certain no brake fluid drips onto the brake linings. Remember, brake linings contaminated with fluid cannot be cleaned. You may need to reline or replace BOTH rear brake shoes if only one of the linings is effected.
|Ed, I'm thinking you just need to bleed the air out as that your longest run and may take a while. I primed my line with a squirt can full of the brake fluid to ease the bleeding pain. The E brake is mechanical so it really has no bearing on the issue other than it works.|
|Mike Hart (52 TD 16378)|
|...and sometimes you have to get fluid past the bleeders and into the cylinders......|
|Hard to understand why so many leaks. These are new Moss lines hooked up to the original fittings and not one single leak! Only thing I did was to make sure the fittings were washed clean inside and blew dry. PJ|
|P S Jennings|
|Just curious- are you using a proper brake line wrench to tighten the pipes? The no fluid thing: Follow Larry's flow to check as above, and to expand on that- Forget about air., fluid must come out of the RR line, then if the banjo on the line, the out of the banjo bolted onto the cylinder out of the banjo with the bleeder out, then with the bleeder loosely in it should come out of the bleeder and/or around the threads, etc. I have a suggestion: Brakes are about the single most important part on the car- if they fail you can die, or injure someone else. Sometimes experience is important. Using the Gasolia frankly scares me- not a good idea at all. I really think it may be time to have an experienced mechanic/friend/club member or someone help you in person. If I wasn't so far away I would be glad to. George|
|ed, i don't even know how you would use gasilia in a flared fitting. as you probably know, the seal is the pipe to the flare..the threads are there just to provide pressure to the pipe/fitting mating surface. i would be very through about removing any trace of that product. the rest i have would echo what others have posted..service manual says start bleeding at right rear and do not move to the other wheeels antil the right rear is COMPLETELY bled. best of luck. tom|
|Ed, I failed to mention something I do when threading two brass or aluminum pieces together and that is I put a very small amount of white lithum grease on the threads to reduce the friction between the two like metals. It seems to make things go together easier. PJ|
|P S Jennings|
|Forget the sealer Ed. It's made for sealing threads and thats not the surface your looking to seal here. Tighten up the leaking fittings till they stop. Stop pumping the brake pedal. This action areates the silicone fluid and it takes forever for the air to work its way back to larger air bubbles you can bleed out. The tiny bubbles will still compress just like big ones if you leave them in the system. Just push the pedal and have Cindy crack the bleeder open or better yet have Cindy step on the pedal and you work the bleeder. Ater the pedal goes to the floor she should tighten the bleeder and you can release the pedal and do it again until no air is seen coming from the the bleeder. Make sure you have a clear plastic tubing running from the bleeder nipple into a clear container that you will trash when finished. Start with the wheel fartherest from the master cylinder and work your way around with the closest wheel last. Be sure not to let the master cylinder get low. |
As for the bleeder, make sure that it isn't plugged with crap. Remove it and blow some air through it. May need to run some thin wire through it to clean it out.
|Thanks all. Just to clarify, old parts were all of the car and have been carfully cleaned and polished within an inch of their lives, inside & out. (The brass even got Brasso'ed and sprayed with "Lacquer for Brass" recommended in the archives. And they look good if I do say so myself.) Pipes are brand new. Brake drums have been left OFF the car during bleeding process so I can see the wheel cylinders and watch the shoes move. The cylinders & MC (freshly rebuild by myself!) do not leak one drop!! YEA!! (One small victory for mankind!)|
The current problem is the fluid just won't get past the rear 3-way union to the RR side. I loosen RR pipe at union and fluid IS THERE on pedal press! Air gun thru the RR pipe proves it is not clogged. Only thing I can see different than suggestions is the bleeding order I used. I started with RR but has this same problem - no fluid coming out bleeder. So I blew it off and moved on to LF (because I can reach it from brake pedal easily.) Then on to RF then LR. After some "forceful" tightening of leaks, these 3 wheels now work as they should. I don't have an oil can or I would try loading RR pipe manually. If all else fails I'll get one tomarrow unless anybody can think of something else "creative".
|I used the Moss brake pipes some years ago with good results. If the flares are proper, and clean, they should not have to be tightened beyond reason. I used a system that Moss used to sell-I don't recall seeing it lately, but if you can get it, I highly recommend it...I think that it was called EZ bleed. It used pressure from one of the cars tires to pressurise its fluid filled bottle and push its contents through the system by way of the filler plug on the master cylinder. Its the opposite of the vacuum pump bleeder. You merely open up the furthest bleeder and wait until you have a clear, bubble free stream of fluid and then move on to the next furthest, etc. Its especially handy when you want to flush and refill the entire system.|
|Try swapping bleeders.|
|Mike Hart (52 TD 16378)|
|Air will travel where fluids will not Ed. If the fluid comes out of the three way fitting like a faucet when you push the pedal, If you just see it wet or a trickle when you push the pedal then you need to remove the three way and find out whats in there. Then take the line from the right rear off and check for kinks. Most likely won't find any. Straighten the pipe back up and run a small stiff wire through the line this will confirm that it is not choked off internally. If all check out above then there would be no reason that fluid would not travel to the end of the brake lines. Have a look at the flared end of the pipe and make sure it still looks correct and didn't somehow get deformed and is closing off the opening when installed. |
I have would have serious reservations about pushing the pedal without the drums on. It would be real easy to pop the cylinders out and then ruin some brake shoes along with having one hell of a mess on the floor.
|Ed, I think you gave the solution by mentioning that the drums are off in your last post. This means that every cilinder easily goes out quite far (because no limitation by the drum)and the one(s) that just happens to have the lowest friction, consumes the oil provided by the MC pedal stroke. Pressure only builts up if the movement of the shoes is stopped by the drums. I would suggest that you put on the three drums and see what happens now at the right rear cilinder. Greetings, Huib|
|Okay, now everybody sit down and get ready for a good laugh at my expense! Out of desperation I opened up a line so I could run compressed air thru from a known "good" side to the RR side. Nothing! So I took off the RR pipe at the union and ran air. Comes right out the RR bleeder like it should! So I put the pipe back on for the 50th time. Try again. No air at bleeder just like before. So I loosen the pipe at the union half way just for kicks blow some air. What!!! Air comes out the RR bleeder. I hand tighen the pipe to the union and when it's almost all the way in the air stops again! HUH???!! That's impossible. So I remove the entire union to inspect.|
No, not an insect. No, not Gasiola (which I gave up on by the way). When I sprayed the "lacquer for bronze" on the unions I inserted a "plug" of tin foil in each threaded end to protect them. When I inserted the pipes yesterday I first carefully removed the plugs. NOT!! Don't ask me how, but a 1/8" piece of foil remained in the union and became a new "plug" when I screwed in the pipe. Tighten the pipe, tighten the plug!!! Problem found. I'm taking a break and will start from scratch shortly.
Moral: Don't use foil to make protective plugs for stuff. Find something else!
When you stop laughing, give yourselves some thanks for helping me wade through this one. What's next?
|...glad its solved....it will make a great story at one of the GOFs in a few years.....we all have them.....|
|On the good side Ed, think of what you've learned (us too).|
|Mike Hart (52 TD 16378)|
This thread was discussed between 30/10/2010 and 31/10/2010
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