MGB: Advice on Brakes

Hi everyone, well it’s been a few years since I’ve been on the forum. Heck, I think since my last post, I’ve moved, had 2 more kids, and switched jobs. Family and the job has taken up most of my time, but I finally have some time in the evenings to work on the B that I bought a couple of years ago. Right now I’m off work due to an injury, so it’s given me a little time to get a work plan together. Before I went under the knife last week, I took off the Rostyles to have them blasted and coated (will add those pics when done). So when I took off the wheels, I got a good look at the brakes, and it looks like they need attention. Both rear cylinders appear to be leaking and the front calipers don’t look much better. On top of that, all 3 hoses are dry rotted and cracking. It’s obvious nothing’s been touched in a long time. I couldn’t even spin the drivers side rear wheel in neutral up on the jack stands, won’t know why until I get into it I suppose.

If any part is questionable, I just want to be safe and buy new. My plan is to get everything that I need to get the job done so once I’m recovered I can install, hopefully in the next 2 months. After reading nearly every past forum for brake jobs, I still need advice.

I don’t have contact with the PO and I don’t know what type of brake fluid is in the system right now. Is there a way to determine this? In any case, it seems to me that right now would be a great opportunity to switch to DOT5. What is the best method for flushing out the entire system to make the switch? Do I need to be concerned about seals in the system when I flush? Do I have to buy a brand new pipe set, or can I just flush out the pipes I’ve got? They appear to be fine, no kinks.

Any advice will be much appreciated, I think I’ll be asking a lot more questions about the brakes as I go along, so please bear with me. I like to think of this forum as the “Haynes Manual on steroids” – advice and direction for every situation with the B. I’ve always valued the advice of the forum readers, thanks in advance for suggestions.

Switch to DOT 5 only if you clean out every hydraulic component in the brake system. I have converted 6 cars to it and it's great, but you have to start totally clean to be trouble free for 14 + years like the ones I kept that long were.

Are you going to drive the car or let it sit? If you are going to drive it, then I personally would stick with DOT4. If it is going to sit a lot, then switch to DOT 5.

Some people claim you have to renew every rubber part to make the switch. Moss claims a thorough bleeding will do.

I would change the rear slave cylinders (they are usually pitted). You can usually rebuild the front calipers (they usually are not pitted). Definitely put on new hoses. Personally, I think you can do a better job of rebuilding a M/C than the rebuilders - many here on the BBS think otherwise.

My two cents.

when you replace the calipers be sure to install the stainless steel pistons. Also use the new EBC green stuff pads and brakes.... About the rear brakes....when you take all the old stuff off, look at the axel seals, they will also need to be replaced. Rubber lines relace with the steel braided ones. Of all the things a car can do, stopping is the most important.

My experience after a longish lay up was that every hydraulic part had to be replaced. Those that I didn't replace started leaking within a few months. Agree on stainless pistons in the calipers, and I would fit new slaves in the rear as they are cheap to buy. Definitely a good idea to replace the axle seals while you have the rear in bits - my seals started leaking in about the same time it took the brakes to start leaking.

Not sure about the master cylinder, but for me I would fit new seals at a minimum, and preferably replace or have the master rebuilt. Once I had done all that I would put any modern fluid in and replace it evey couple of years. Fozzie

Im in the process of the same conversion. I was advised by a local brake specialist (Old German Guy who only does brakes) to run metho (white spirit i think i US) through the lines and blow the pipes with compressed air at least twice (everything disconnected of course).

If my Master Cyl experience is typical, they are usually pitted. S/S inserts are not great, they never pit but aren't kind to the seals, I found it no more expensive to buy a new cylinder. Mine is a dual system so it wasn't too cheep.

Best advise I can give is do the whole system and be done with it. Good time to do the clutch hydraulics also. Shoot some aresol brake clean through the lines followed by shop air. It evaporates pretty well. Rebuilding the master depends on the condition of the bore. Most times they are pitted & won't seal. You'll have to take it apart to find out. As stated, wheel cylinders are cheap & I personally wouldn't bother trying to rebuild them. Calipers can usually be rebuilt. My theory, and it's only an opinion, is the calipers get more heat in them and don't collect moisture as bad, therefore don't corrode as much as the rest of the system. Obviously you need new hoses. I reserve comment on brake fluid since that has been hashed over many times before. Good idea to flush the lines of gunky fluid regaurdless of what you put back in.

Great advice from everyone. I also recommend braided stainless steel brake lines. You will be happy!

Not trying to keep this thread going but just another thought/tip. Couple of guys sugested replacing the axle seals which is good advise. Nothing worse than a new set of shoes soaked with gear oil.
Also, with the backing plates unbolted, do yourself a favor & put the wheel cylinders on the backing plates off the car. The clips can try your patience and it's easier on the workbench. Just did a set on the car & it's doable but if you have the plates unbolted...you could save a lot of bad words. :)

Thanks much for the tips, I'll let you know how it goes. I think I'll be able to knock it out in November if all goes well, now I've just gotta spend the cash to get the parts. I'm sure there will be more questions about it all, thanks,