Fudge values and bearings

• Correct bearing tightening instructions

• Brakes work again, even when turning
• No wheel wobble at high speeds
• Greatly reduced chances of dying
  

I strongly believe in the value of fudging values from time to time. 5 ft/lbs? Finger tight! 0.05mm tolerance? Finger tight! 32 PSI? Yup, finger tight!! Please note that I am not an accountant, and do not work in the finance industry (where a lot of 'value fudging' goes on as well, I imagine...).

Unfortunately this does not always work. Bearings, for example, are an example of one of these situations. I learned that this week when the brakes on my XJS stopped working every time I made a hard left or right.

I recently changed the bearings on the XJS, but followed my usual method of tightening the end nut: finger tight plus a turn of the wrench. Generally that's good enough (as it seems to be for the MG). Tightening too much leads to premature wear of the bearings, and that lovely grinding noise you sometimes hear on old cars. Too loose has never been much of a problem, so I didn't think too much of it.

Well, I was wrong. Turns out the XJS needs a full 25 ft/lbs on the end nut (as pictured above, on the MGB, before pin removal), backed off one flat (and more if necessary to fit the pin back in). After adjusting this the brakes returned to normal, and high-speed driving stabilised a bit. Turns out the nut was loose enough to let the rotors move around enough to push back the brake pads, but only when the wheels were turning. So really the brakes were working fine, it's just that they had to be reset each time I made a turn.

So:
Here are my general bearings instructions (for the MGB and most cars that aren't Jaguars):

• Tighten the end nut to 5 ft/lbs while turning the wheel. If you hear grinding or anything like that your bearings may be bad, or some dirt may have entered the hub. Clean the hub and make sure you pack it with (clean) grease.
  
• Loosen if necessary to enter holding pin
• Reassemble the wheel (keep it jacked up).
  
• Check for wobble by holding the wheel on the top and bottom and try to make it wobble. Then hold the wheel on the left and right, and do the same. If you feel any wobble or anything that seems too loose, tighten the end nut a bit, and recheck.
• If everything seems right, take your MG out for a ride. If you do not notice the same or better performance, something is wrong (duh, this counts for anything I guess...). The best speed, in my opinion, to find problems is around 70 mph. Good luck.

Mind you, despite the bad braking and wheel wobble I still did a 400 mile road trip at 80+ mph speeds....

Rear (drum) brakes

• Replace wheel (brake) cylinders

• Resolved horrible braking power
• Stopped losing brake fluid
  

I think that at this point I don't need to make any more jokes as to how this project is turning out to be one giant Pandora's box. Fix one thing, get ten more problems. Clock starts working, tach dies. Etc. So I'll just cut to the chase: fixed rear brakes, passenger side headlight doesn't work on regular mode (replacing bulb didn't fix it).

Despite changing the front brakes, I still wasn't stopping in a reasonable distance. After removing one of the rear wheels, the grease and liquids all over the place quickly revealed that the wheel cylinder was broken and severely leaking fluids. This is contrary to my original thought, that it had locked up. The other wheel cylinder was fine, though very rusty, so we replaced it anyway.

There are two ways to do this. The first way details the long, tedious (but correct), way. The second is the short-cut I recommend to anyone who knows what they're doing (Takes about 20 minutes instead of an hour and half). Also keep in mind to use something to hold the brake pedal up. I attached it to my steering wheel using a bungie cord.

1. Remove wheels, jack up car (rest floor jack on differential, I rested the jack stands on the reaf suspension leafs).
2. Use a 7mm hex bit to remove the two screws holding the brake cover. I had to tap the cover gently with a hammer to get it off.
3. Remove the two retaining springs (see image below - click to enlarge).
4. Remove the top spring (see image above). The shoes will start coming lose here.
IMPORTANT: Remember which shoe goes where!!! Make a note of all holes and pins in their appropriate place, so when you put everything together later you know what you're doing! You can severely damage your brakes if you do this wrong!!!
5. (You don't really have to do this, we didn't) Remove the bottom springs and take off the shoes.
6. Unscrew the nut holding the brake line to the wheel cylinder. Keep in mind that you'll be losing brake fluid here, so put a pan underneat the wheel.

7. Remove the retaining clip on the back side (where the nut was).
8. Remove the wheel cylinder. Note that there are three holes where the cylinder was attached: one for brake fluid, a bleed valve, and a pin to hold it in place.
9. Take the new wheel cylinder and pour brake fluid in it. Squeeze the outsides together in bursts to let out any air still in the cylinder. You do not want air anywhere in your brake system.
10. Install the new wheel cylinder, keeping the three holes and what goes where in mind. We had to use a hammer to nudge it in properly (the holder pin was a tad larger). Attach the new clip (we weren't able to, so we just reused the old one) and reconnect the brake-line nut.
11. Reverse the installation, bleed the line, and you're done! Keep in mind that the reverse installation takes a while, and depending on how many springs you removed, can be rather tedious.

I also cleaned the brakes before I reassembled everything. One should generally use brake cleaning fluid for this, lacking that I used carb cleaner.

Rather than do all this you can also try to jimmy out the shoes without removing any springs (pull them apart so they go over the wheel cylinder), and wedge the wheel cylinder out. We did this for the second brake, which worked out fine and took less time. (This is the second method)

John Twist at University Motors has a video on how the brakes look and work.

Many thanks to my girlfriend's father, thanks to whom the whole installation could be done in less than 3 hours. And of course my girlfriend for taking the pictures.

New Front Brakes!! Finally!!!

• Changed front brake pads and rotors

• Minor improvements in braking (much better results when I replaced the wheel cylinders)
• Brake pads worn, reveal uneven calipers.
  

Several months ago my grandfather gave me the gift of safety in the form of reliable braking. Knowing quite well what happens if you don't hit the brakes on time (and a building is inconveniently in the way ;-) ), he advised me early on in this project that I wear my seatbelt and obey speed limits. When he heard about the B's poor braking he jumped on the occasion and bought me a set of new rotors and pads.

This was before I left on my trip, and after I got back the weather rather dismal for many weeks. Last weekend, about three months later, we finally had two days in a row of pleasant warm weather. Perfect weather for fitting new rotors and brake pads.

The following is a step by step guide on replacing both the rotors and the brake pads. The first time I did this took me about five hours to complete, the second time about an hour and a half. Be ready for some really dirty, greasy work, as well as many frustrations with pins. Also I would recommend keeping a pan under the caliper while working on it (to catch dripping brake fluid), and have a box nearby to rest the caliper on while working (so you don't stretch the brake line). I must also stress people use a floor jack and jack stands while working on any of this (I used to use the jack the car came with ... very very stupid).

1. Loosen the wheel lug nuts, raise the car, remove the wheel entirely.
2. Remove the two pins and two panels on the caliper holding back the pads. You'll have to play around a bit with the end of the pin: straighten it out to pull the pin out (see image on right).
3. Unscrew the bolts holding the outer caliper part, and set it aside. You'll probably lose some brake fluid doing this. Take out the brake pad attached to this part (see image on right).
4. Unscrew the bolts holding the inner caliper part, take it out and rest it on a box or something so the brake line isn't under pressure. Take out the brake pad.
5. Remove the grease cap off the wheel hub (yes, you need to remove the wheel hub to change the rotors). Use a screwdriver to pry it open.
6. Straighten the wheel hub pin and pull it out. This was by far the hardest part of the entire operation.
7. Remove the nut holding back the wheel hub. It's very loose, and you should be able to mostly use your fingers for this.
8. By gently pulling the rotor forward, take out the various components of the wheel hub and place them somewhere, keeping in mind in which order they came out (pin-bolt-washer-bearings). I strongly recommend you not let anything touch dirt, and that you not drop the bearings.
9. You can now (easily) pull off the rotor.
10. Place the rotor in a table clamp, and remove the four bolts and nuts (with washers) holding together the hub and the rotor.
11. Now take off the old rotor, attach the new one, and reassemble everything in reverse order.
UPDATE: Read this on the wheel bearings and how far to tighten the end nut. This is a safety issue! (Skip to the end to read the instructions if you don't feel like reading the story behind this discovery.)
12. When refitting the calipers, make sure the cylinders that press together to apply the brakes have been pushed back into the housing. An easy way to do this is to place your old brake pad on top of the cylinder and squeeze it together with a c-clamp. You'll see brake liquid oozing out. Be sure to install the new pads!
13. Make sure you bleed the brake system before using the brakes or reattaching the wheels! This is to remove all air from the brake lines. With the bleed valve closed, press down the brake pedal four times, holding it down the last time. Open the bleed valve, and close again. If brake fluid did not spout out in a decent stream you still have air in the lines, so repeat till this happens. Make sure you have enough brake fluid to start with or you'll just pump more air into the system.
14. Friction after putting in the new pads is normal. As long as you can still turn the rotor with your hands you're fine. By pressing the brakes you shouldn't be able to turn them anymore.
15. Now do the other side, and you're done!

The old pads were extremely worn, though they still had some life. This is probably why I had to push down so hard on the brakes; now I don't have to push down as hard on them to brake. However, braking is still not as good as it should be. I'm guessing the rear brakes have locked up (which is probably also why my parking brake doesn't work anymore), so I'll be looking into this soon. I'll probably be replacing the cylinders on the drum brakes (locking up is common).

The pads on the driver side were worn down at an angle, suggesting that an uneven amount of pressure was being applied. I'll have to look into this in future, and perhaps recalibrate or even replace the caliper. But that's for another time.

Many thanks to my grandfather for the parts, my friend Gautam for some much needed brute force help, and my girlfriend Luz for taking detailed pictures and assisting throughout the procedure (she's changed brakes many times before, and unlike me actually knew what to do).