Rear brakes in bad shape. Replace or upgrade?

[Seth Horwitz]

I definitely don’t have the room, and likely don’t have the skill, to do the brakes on my purchased ‘76 2002, so it’s at my mechanic. The car has been there FOR A LONG TIME (again space issues) so there could be a number of reasons why the brakes don’t work, but that’s neither here nor there. I take responsibility, regardless. 

 

Symptoms: 

1) There’s a brake fluid leak, but not in the lines or on the brakes themselves. My mechanic thinks it’s in the master cylinder, and will diagnose. 

2) The e-brake cables are a mess, but he said they weren’t just stretched and seemed kinked and deformed. I figure a 40 year old car, that sat for over 25, could use new cables anyway. No big deal, just another datapoint. 

3) The fun part, the rear shoes seem to be engaged, to the point where you can’t even push the car, and need the engine to move the car around his shop. This wasn’t the case when it was first dropped off by the last owner, but that was a year ago and, again, that’s neither here nor there. I don’t think adding more fluid is going to fix it. 

4) He can’t get the drums off to inspect without going at them with a mallet. He wanted my permission, so I told him to just do it. He said parts may break, or maybe not, so he wanted to check, first. Again, I want to drive the car, and told him to just get it diagnosed so we can fix it. 

 

Anyway, and I’d be impressed if you could, anyone who thinks that they can diagnose the issue from afar would be much appreciated. So, I’ve got the original M10, and I don’t think it’s ever been rebuilt, nor have I done a compression test. There are either 50K or 60K miles on the clock, likely true mileage. (Again, the car’s been there a long time, as the seller dropped it there, so I don’t remember.) I had been thinking about going the M20 route right away, last year, but given that I’ve only driven the car a few miles before I bough it, I figured I’d just let him fix it as-is, drive it to the grocery store and pharmacy while I’m locked down for several more months (I’m in NY), and then reevaluate. 

 

All of that said, how would you go about replacing these brake components? Are there any components that I should do, even if they haven’t failed, yet, just because others are being done? I’ve seen people rebuild boosters and then cause huge problems downstream on other makes.

 

1) Do I replace the existing parts with identical new parts? This is clearly the cheaper option. 

          OR

2) Do I upgrade with something from IE or elsewhere? Figure I’m 50/50 about whether or not I upgrade to a more powerful engine in the future. Will I enjoy the different brakes with the stock M10 that’s lost power over the last 40 years? (Bigger drums, or discs? You tell me.) If they’re so powerful that they mess with the overall balance and feel of the car, then I’d rather just replace stock pieces, and chalk that money up as lost if I go bigger on the engine, and then upgrade the brakes anyway in the future. If I do upgrade the rears, should I do the fronts, too? (Upgrade the whole disc and caliper, not just new pads.) I’d want the proper braking balance, and I don’t know whether installing a brake bias control would be enough to do that. Having the back lock up before the front would be something I’ve never experienced.  Any info on that would be appreciated, too. 

 

This car will never see a track (I’ve got a better toy for that) and rarely see the highway, but I enjoy spirited driving, more so than the local police, so I appreciate good brakes. If the car takes a minute to get to 60mph, though, that kind of defeats the purpose of having great brakes that let me do late braking from 50mph a second before the turn, to putter out of it at the apex. Thanks for any advice. 

 

Seth

[esty]

if you want to drive the car for the least amount of money, fix things, it doesn't sound like you have any unusual issue with an old car that's been off the road a long time...if you want to spend a lot of money on parts and labor then upgrade

 

by far, the vast majority of these cars have original brakes

[VWJake]

The first thing that pops into my head is does the shop know about the 17mm bolt head adjusters for the rear shoes? 
 

Don’t waste your time with going to discs or even the larger 320i drums. If you want more action from the rear brakes use Tii wheel cylinders (larger pistons- longer pedal travel but more braking effect) and higher friction shoes. Standard compounds are FF (generally stamped on the edge of any mass produced pad/shoe lining). I think* GG or similar will get you more braking effect as well

[dlacey]

I say repair & replace what you have... brake upgrades are 85% bling on road cars...BMW didnt design a dangerous braking system, it works perfectly adequately when in good condition. I believe originality is easier to setup and maintain because its so well documented...once you start fitting non-standard parts you are on your own and may well be sucked into a spiral of changes in order to get something that works out the end.

[M3M3]

Fix what you have and use a good shoe compound.  They will be great for your intended use!

[zinz]

Stock brake system is way more than adequate. New shoes, drums, wheel cylinders, soft lines and e-brake cables... all properly adjusted will out-stop many modern cars. No point “up grading” a stock, street driven 2002.

 

Ed Z
 

 

[NYNick]

Seth baby,

 

Feel free to PM me.

 

Where in NY? If it's in Westchester, let me know I'll take a ride to the shop.

 

Your issues aren't all that difficult. Leaks are easy to spot. Where is it coming from? Could be the rubber lines. Gotta replace them anyway. Not expensive.

Your "e-brake cables are a mess" quote intrigues me. You're determining that from the inside of the car and the way the brake handle feels? They may need to be simply adjusted, but of course you need the drums off to inspect what's going on. 

 

Rebuilding or fixing these brakes is easy and cheap, except for the MC. It's pretty common to use a BFH to smack the drums to get them loose enough to come off. Nothing should break. Once off, I'd replace the drums (Brembo), the shoes and the cylinders. Cheap. The hard part may come from two things:

 

1) It's VERY common for the rear shoe adjusters to be frozen with rust. It took me FOREVER to get them loose and working properly. Most monkeys strip the bolt end which is on the reverse side of the wheel and kinda tough to get at. Lots of PB blaster, a torch and muscle got mine loose. Please be careful (tell him!) to not strip that bolt. You can't replace it individually and it needs to be working.

 

2) E-brake cables are also commonly rusted or stuck in the tunnel that travels under the car to the E-brake handle inside the car. Cheap to buy, they can be a bitch to get out. Mine was horrible. I got 90 percent of it out before it jammed right at the end. After days of struggling, I finally just put my torch where I thought the end of the cable was inside the tunnel, and breathed nasty smoke for a few minutes, hoping the rubber around the cable inside would melt enough to free it up. It did. Big battle, but then easy to slide new ones in.

 

Your shop doesn't sound all that experienced. I hope you have a lot of confidence in them. It would be a lot easier if they knew 02's well.  There's a shop in Northern Westchester I could recommend. Good luck.

 

Nick

[AustrianVespaGuy]

Get everything off, and -

Clean/inspect:

Backing plates

Adjusters

Parking brake cables

Wheel bearings

 

Replace with new parts:

Wheel bearings (if warranted)

Flexible brake hoses

Hardware kit/springs

Shoes

Drums

Wheel cylinders

You can play around with which wheel cylinders and/or drums, but I'd only do this IF you have a specific personal preference with brake balance or pedal feel that you want to tweak. Otherwise, as others have indicated, fresh stock brakes are just great.

 

Rear discs are only worth it if you can adequately explain to me WHY you want them

['76mintgrün'02]

4 hours ago, Seth Horwitz said:

Symptoms: 

1) There’s a brake fluid leak, but not in the lines or on the brakes themselves. My mechanic thinks it’s in the master cylinder, and will diagnose. 

 

It could also be the clutch master cylinder leaking into the pedal box.  (They share the same reservoir). 

[zinz]

If the Brake Master is leaking, be certain to have the shop check the inside of the brake booster... They’ll need to remove all the brake fluid from inside there, or the booster will fail. 

[jimk]

6 minutes ago, zinz said:

If the Brake Master is leaking, be certain to have the shop check the inside of the brake booster... They’ll need to remove all the brake fluid from inside there, or the booster will fail. 

Also make sure the weep hole on the bottom of the master cylinder (located near the end towards the booster) is not plugged.  There are two shaft seals in the master cylinder.  The weep hole is the leak off from the space between the two seals.  It is there to tell if the primary seal is leaking and if it is leaking, so the fluid won't end up in the booster!

A secondary effect of a leaking master cylinder seal is the peeled paint and corrosion below on the frame.

[KFunk]

Stock brakes are awesome if well adjusted, just replace all questionable parts with new.  'Upgrading' often just gives you things that don't fit properly and make it more difficult to maintain.

'02 brakes are a little deceiving for many people that have just gotten old unmaintained cars, and when you feel the brakes are weak you blame the nature of the system and knee-jerk toward upgrades.  With modern disc brakes like we have on other cars, those things will brake just as strong even when the pads are long past dead, then metal starts grinding on metal and it stops even harder, until finally you take it to a shop or caliper falls apart and you lose all your fluid and all braking, which rarely happens because people take heed of the horrible noises first.

But with '02s, the rear drums really do need adjusted periodically or the braking will slowly get weaker and weaker.    When you tighten up the rears, it will stop noticeably better, way better.  You may also have ancient brake fluid that is mostly water, and a flush of the system will dramatically improve brake feel.

Edited May 9, 2020 by KFunk

[ray_]

No one has yet specifically mentioned the importance of quality pads and shoes. 

 

I didn't bother researching what pad compounds are good, I just ordered from blunttech.

 

On my ugly car, which was sitting, mostly apart, for a dozen years I replaced every component in the hydraulics other than the T in the rear lines, mostly because I hate working on brake hydraulics and didn't want to do it again anytime soon.

 

As others have said, a stock system, properly adjusted, works really well.

 

GL,

[TobyB]

If the rear drums are stuck because of the shoes, there are 3 causes, but by driving around you've eliminated 1.

 

2: hydraulic pressure from the master, if the linkage is misadjusted to not allow the piston to return far enough.

    Or just rusted up enough it's not returning to the top of its travel.

 

3:  adjusters too far out.  Easy to do if you adjust them with the wheel not bolted up solid.

 

Before malleting, have mechanic release the adjusters (17mm bolt heads on back of backing plates- use caution, lube and heat if needed)

and try again.  If that doesn't work, have mechanic open bleeder.  

 

THEN mallet may be required to de- rust the drum from the hub.

 

I suspect your master is shot, misadjusted, or both.  Or, hell, just the linkage is rusted up and not

letting the master retract all the way.  It's important, because there's a small 'equalization' port that opens

to the reservoir to let more fluid in, but also, as the brakes heat, let the expanding fluid out.

If it doesn't get to open, the brakes can lock up.  

 

Oh, stock stuff, for sure, with good quality pads and shoes.

 

(Jim, I don't think there's a weep hole to outside, as that would be a 'vacuum' leak)

 

t

 

[halboyles]

3 hours ago, VWJake said:

does the shop know about the 17mm bolt head adjusters for the rear shoes? 

 

Yes!  If these are out of adjustment and tight, rotation of the wheels will be difficult.  And these will definitely require some penetrating fluid and/or heat to free up before they will rotate.  The eccentrics both rotate toward the axle to loosen the brake shoes, and outwards, away from the axle, to tighten the shoes.

 

The original brake adjustment tool makes this tedious task much easier and eliminates the rounding off of the eccentric bolt head.  Since these are NLA, I've had a repop made of this tool just for this purpose.  See pics below.  We've made this out of heavy duty stainless steel and improved the design by making both ends open.  They are $37.50 plus shipping. Please contact me here for more info.