Help with brakes

I have a buddy who has a buddy mechanic who he said is good with working on cars, but also allowing you to help out. He used him to do some brake work. While he said it was an easy job, it was good having him help so he could know what was being done was correct.

We're going to head over there with the MG tomorrow. To stop, you really have to hit the pedals hard and it doesn't react all that well. I'm thinking that it at least needs some new pads. I'd also like to take off the calipers and paint them. Of course I know nothing about cars. I just wanted to get a little info from you all before I see the guy tomorrow so I appear somewhat educated, haha.

So I guess here are my questions:

-If we take the calipers off, will the brakes have to be bled?
-If not, should the brakes be bled? I doubt my dad did it when he had it (since 2000). Could this be part of the non-responsiveness?
-If we take off the calipers, is painting them as quick and easy as it sounds? I'm no expert painter, but I've done my fair share of painting die-cast cars and other things.

My ideal scenerio is to go there and have him take off all four wheels and give me the wheels and calipers so I can refinish the wheels and calipers before reassembly.

Check the brake fluid. You can open a bleeder and make sure that it squirts. Brake jobs on my '69 is pretty easy except for getting the retainer ring back on but there are posts on that one.

Generally, if the brakes don't work that well or need a lot of pressure it's because the rears are out of adjustment. Even though the front brakes account for about 80% of your stopping power, the rears are the ones which give you "pedal".

If you don't detach the brake hose from the calipers, it's possible they won't need to be bled, but why take the chance? Kinda gives you the opportunity to get some fresh, clean fluid in there. Seems to me it would be kind of a pain to paint them while still attached, but that's just me.

It may be you just need a simple brake job, but just as likely (more likely?) that you should replace the brake hoses (2 in front, one in rear) and the rear cylinders along with pads, shoes, and turn or replace drums/rotors. If you search the forum here, you'll see many recommend replacing the hoses every 5-8 years (but I'm no expert).

Also check the rear brake hard lines on the rear axle, as they often get crushed by tow operators.

It may sound bad, but you can replace the entire MGB brake system from master cylinder to pads for less parts $$$ than a simple brake job on many modern cars (such as my VWs....).

Good luck!

Brakes are kind of important. I don't know if you're planning on doing the painting, reassembly, and bleeding in a day, but if you are I hope that you are never following me. (Sorry for being blunt.) There are lots of places on this forum and the internet on brake maintenance. Try to find one that applies to your model of car, there may be subtle differences that are important.

1)The pads and shoes should be checked for lining thickness and condition, any brake fluid or oil on them (?). They don't stop well if wet and there is no way to clean them. Replace them.
2)The pistons in the caliper and wheel cylinders should move and not stick. The calipers should move on the mounts without binding.
3)The rotors should be flat, and drums round within spec. A brake shop will know how to check them.
4)The system should be flushed with new brake fluid. Do you know if it is DOT 3 or DOT 5? They can't be mixed, and if you change, all new rubber pieces need to be replaced in the master & wheel cylinders, calipers, and hoses.
5)You need to know how to bleed them, or feel comfortable that this friend of a friend really knows. Remember you will be driving the car, not him.
6)Brake fluid is a great paint remover. Have plenty of rags, degreaser, and water to clean up and flush away spills.

Once you get the brakes working you can pull off the calipers and hang them with a coat hanger without disconnecting the hose, so you won't need to re-bleed. Don't rush this. If you haven't been driving the car up until now, you don't have to be driving in the next day or two.

Keep us informed in what's going on. Good luck

Thanks guys. Yes, this friend of a friend is a certified mechanic that has his own garage. Your posts make me more confident that I am making the right choice by having a guy who knows about cars be in charge of this brake job instead of me doing things myself.

I figured it'd take more than a day. I was hoping I could get it knocked out (painting the 4 wheels as well) in a week or two.

Resist any temptation to unbolt the calipers form those real convenient bolts facing out. That will split the caliper and you may never get them to stop leaking.

I split mine on purpose so I could completely rebuild, and powder coat. Still have a 1 drop per day drip on one side.:(

Take two cars over there. You are going to need something in which to get home.

Your mechanic guy is going to do, or suggest that you do, the following.

Put the car on jack stands and pull all of the wheels.

Do the following for each front caliper, one at a time.

Apply as much pedal pressure as possible and then release the pedal, then open the bleeder screw and see if fluid is expelled with your foot off of the pedal. Fluid expelled with anything more than the slightest dribble means that the flex hose to that caliper is swollen internally and must be replaced. If one side is bad, replace both hoses.

Also, after depressing the pedal and releasing it, before opening the bleeder, try to spin the hub. If you can't spin it or if it is difficult, the above paragraph should be done, but once the pressure is off of the pedal AND the bleeder has been opened, try again to spin the hub. If it spins freely, the caliper pistons are probably good. If it is locked or still has a lot of resistance to turning, one or both caliper pistons are sticking and that caliper must be overhauled. IMHO you should do both calipers even if only one is found to be faulty.

Go to the back of the car and similarly repeat the pumped up pedal and full release routine followed by cracking of both the rear bleeders. Rapid expulsion of fluid from either bleeder will again indicate pressure retention beyond the flex hose, telling you that the flex hose is bad.

Pull the drums. Inspect the lining thickness and peal back the dust boots on the cylinders. Any fluid there means overhaul or replacement time. While you are at it, look for a wetness coming down on the inside of the backing plate from the hub. If you see any, that axle seal is bad and must be replaced. Measure the inside diameter of the drums. I forget what the standard dimension is so look it up if it isn't cast into the inner wall of the drum. Any measurement larger than that is too much. You might get away with a few thousandths, but any more than that and you should toss the drums, plural. If one is bad replace both.

Inspect the steel lines spread across the axle housing for being smashed. As per the above, this is a common thing to happen when a car is lifted and towed backward by a wrecker. The J-hooks used, smash the lines. If needed, replace the damaged steel line(s).

While you are under the car have someone operate the parking brake while you watch the action of the cable and linkage rods. Your compensator is a simple rubber thing that allows the rods to react properly when the lever/cable is actuated so you don't have to worry about a binding of the metal compensator used on pre-RB cars.

After doing what you have to do to get the rear brakes in shape, adjust one brake to be completely locked up. Fire the engine off and let it idle long enough to where it runs smoothly at lower revs. Then, with the car in first gear, raise the idle to about fifteen hundred or two thousand as you slowly release the clutch. The non-locked side will begin to rotate. Raise the engine speed up a bit more and as up reach say twenty five hundred revs, depress the parking brake thumb plunger and jerk up on the lever several times. Don't hold it up, just do a few jerks, enough to bog the engine down a little. This will center the shoes in the rotating drum.

Go to that drum and use the adjuster to bring about a slight drag when you try to rotate the hub.

Go back and repeat the jerking the parking brake routine before coming back to the drum once again to see if there has been any change in rotation resistance. If the hub spins more easily, screw the adjuster in one flat before repeating the whole shebang and testing rotation again.

Once you are happy with the way things feel at that drum, screw the adjuster in until you lock it up before moving to the other drum and repeating the same song and dance. Once you have that second side set correctly move back to the first side and back the adjuster out to where you have the same rotational resistance that you have on the second side.

At this point you will have the wheel brakes in good order.

Time to move on to the master cylinder.

First, if you have or have not bled the hydraulics to the point of getting clean fluid out of all four bleeders, flush and bleed again until you are positive that all of the bad stuff, along with the air, is out.

Now test your brakes for feeling, both with the engine running and with it shut down. If they feel right then there is a good possibility that the master cylinder and booster are okay. If they still feel hard or soft or otherwise odd, you will need to deal with the cylinder and booster.

BTW, with the engine off, you might also depress the pedal several times and holding it down before ALMOST releasing it completely up. With your foot resting a little more than slightly on the pedal, pulse your pressure slowly and lightly, keeping that general steady pressure. If you sense that the pedal is slowly mushing down, your master cylinder is probably bypassing internally.

My inclination is to not attempt to overhaul either one. Some folks here are seasoned enough to get away with doing that but if you aren't one of those guys, it is MUCH safer and, even though expensive, more cost effective to just toss the bad parts and replace them with new.

BTW: As you are evaluating your circumstances with the master cylinder and booster, make sure that the hose running from the intake manifold to the booster is in fact there and that it is secure at both ends. A nasty vacuum leak in that circuit will certainly cause a need for increased pedal pressure. A missing hose with the opening at the manifold plugged will do the same.

Sorry for the rant, but brakes that stop the car straight and without undue pedal pressure or softness are THE MOST IMPORTANT system on the car.

Hope this helps, Jack

Good one Jack (tu)...those instructions should be put in the brake section of the library under INSPECTING AND ADJUSTING YOUR BRAKES.B-)

Any time you disconnect a brake line you should bleed at the wheel(s) affected. If you replace a caliper, rear wheel cylinder or any line, you have to bleed the line(s).

I replaced the left caliper and rubber line on my car yesterday afternoon. outside in my condo parking lot. It took less than an hour including bleeding and used 5 tools (two sockets, two wrenches and a pair of pliers). So it's not a difficult job to do.

I got a reman caliper and a new line from Auto Zone. The caliper was $54 plus a $22 core charge and the line was $14.95. I got the other side too, but the left needed doing to drive, the right can wait until this weekend with the rest of my scheduled projects in my sister's heated garage.

Rhett
It's good the guy is a real mechanic, and not some guy operating under a shade tree like me.

David D,
Just to be sure I understand your point, are there two screws that split the caliper ass'y, different from the mounting screws? I thought that I had pulled the calipers on my MG, and they didn't split. Am I remembering wrong?

Jack,
I'm going to write all of that stuff down.
Thanks

Jack up car. Adgust rear brakes with the brake adjuster nut. located inside the hub. Add fluid. Bleed brakes.

Hi Rhett

The 72 that I am working on right now I bought from a guy ($500) who had it parked in his garage for 17 years. My Nephew and I are in the process of replacing ALL the brake components, flex lines, hard lines, master cylinder, wheel cylinders, calipers, shoes, pads, rotors, drums, - EVERYTHING! I know the car runs well but I want to know it stops well too! We are also changing all the springs, bushings, re/re the shocks, new tires, etc., mechanically the car will be better than it looks but first I want to make sure it goes, turns and most importantly stops!
Victoria British and I have become new best friends but at least I will know when tooling around in this car this summer it will be safe to drive!

Have fun - spend the time (and money if need be) to make your brakes right - no shortcuts, no excuses!

Bye for now!

What Jack said!

If you want to use this guy to work on your brakes, let him get on with the job his way. There are differing views in this thread as to what should be done. The mechanic may have yet a different view depending on what he finds when he starts the job.

The fact that you are asking here suggests that you don't really trust this guy, so why let him work on your car.