Laurent1602

Okay, thanks! And the thing on the picture, is that a sort of valve?

Hi,

I rebuilt my brake master cilinder but I guess that was not the best option... When bleeding the brakes it started leaking heavily between the cilinder and the booster. Luckily I was not driving my car already!
A new brake master cilinder is ordered now.

Problem is, there has been some brake fluid in the booster. I cleaned it out with some hot soapy water after reading that brake fluid would cause the membrane in the booster to fail. All has gone well but now I noticed this in the membrane, is this normal?

I couldn't find a MikeS in my street, so I bought 'the right tool' and it was a matter of minutes now, pretty easy indeed! Thanks for the help!

I'm now also removing the clutch master cilinder and rebuilding the brake master cilinder and then I should again be ready to drive 

Oops, I didn't see the circlip! How can I remove that best?

And after that, does the slave slide out forward (to the engine) of backwards? Because backwards doesn't seem to be possible to me, I can't compress it enough and all fluid is already bleeded.

The problem has become worse, until I couldn't keep the clutch in for more then a couple of seconds. Definitely a leak. It turns out that the slave cilinder is leaking, but I can't get it out!

I want to get it out in the direction of the green arrow, but to do that I of course have to remove the other end from the linkage with the clutch (red arrow) but I can't get it out. I can push it far enough backwards, but it doesn't bend enough to get it past the linkage. What am I doing wrong?

Well, I have no idea how long ago the master and slave cilinder have been overhauled. I own the car for a little over three years now and except fluid changes I never really bothered about the clutch so it would absolutely make sense to be wear of the sealings. The brakes and brake hoses however have been completely renewed so no worries there.

I'll just see how it goes now as I don't have the time to do much on my car for the coming weeks. If it's going to be a recurring problem I'll probably renew all cilinders and the brake master cilinder as well, as that is the only part of the braking system that's not yet replaced.

Thanks for the nice and informative write up!

You probably have worn seals (or wear in cylinder bore/s)  in either/both the master and slave.  This would explain no fluid loss.

 

This might also explain hydraulic pressure and pedal effort changes.  Pedal feel/pressure could vary with heat and as you pump the pedal priming the system,  In my experience with 02 clutch hydraulics, older, worn slave and master are prone to losing pressure when sitting for long periods.  E.g., an E9 that hadn't been driven for months had a soft pedal when first started.  No visible fluid loss either.  with a couple of pedal pumps, the pedal became firm again.  The best cure would be to replace seals or worn bores, but a quick bleed seems to keep her on the road. 

I agree with your explanation but this doesn't seem to be the case here. It first happened when I was on a drive (after 10km or so) and when I started it today (so when it was cold) it felt soft. I'm really wondering what it could be... For now I'll just see if it happens again.

Simple indeed........... unless you have the one piece carpet. While you are in the pedal box, make sure it is dry and no fluid has leaked in from the clutch MC.

There you say it... I have a one piece carpet, damn   

Just checked it, everything is fine, no fluid!

And now the mindblowing part (at least for me). I just started the car to put it back in the garage, and the clutch felt normal again. Another thing I suspected was that it was engaging a lot earlier when it felt soft, that too was again gone. Very strange sice I drove the car today for 60km without any improvement. 

You say that the clutch is working as it should, so Roadhog0 may have the simplest solution.

Check your pedal box first. Pull back the carpet, underlay, and rubber cover. The spring is on the left side at the base of the clutch pedal. Confirm that it is working as it should. If it's broken, or slipped that could be you fix.

Good luck.

DSC02001fx1.jpg

Well, since it's that simple I'm out to check it right now! 

It could be helpful if you offered more detail regarding your ride, including general condition, and any recent work performed.  Not clear whether your clutch is engaged mechanically or by hydraulics, but since you mentioned no loss of brake fluid I will assume that with you are employing hydraulics.

 

Loss of  brake (clutch) fluid would indicate failing hydraulics so that you would likely feel a soft pedal or a pedal requiring multiple pumps to fully engage/disengage the clutch.  But hydraulic problems could still remain - without fluid loss.  Not unlike a problem more often associated with old or degraded brake hoses, an older or defective hose can swell internally, restricting fluid movement and pressure release.  At it's worse, degraded flexible hydraulic hose can act as a one-way valve, resulting in pressure to the slave cylinder that does not fully abate, despite taking your foot off the clutch pedal.  The net effect is similar to leaving your clutch pedal slightly depressed or a power assist.  

 

Another possibility is that one (or more) of the pressure plate springs or "fingers" has failed or is failing.  This might explain reduced pedal effort.  The clutch could still function, but the clamping force of the pressure plate/disk/flywheel would be far less than optimum.

 

Other possibilities could involve the clutch fork and the bell housing pivot upon which it rides.  Without lubrication, the pedal effort increases.  It seems counter intuitive and a long shot, but misapplied grease above the actual contact points "could" work its way down to the friction point. 

 

IF you had a mechanical clutch linkage, I would look to recently lubricated, tightened or replaced linkage.  But that brings up the possibility that your pedal assembly is laden with dirt and rust.  If you were one of those folks who spray or drop oil into the pedal box area, it might lubricate things, but if the linkage is worn, maladjusted or contaminated with dirt, the fix might be short lived.  Failing motor mounts or transmission mount might negatively affect mechanical clutch linkage operation.  Conversely, replacing mounts might make mechanically controlled clutch operation smoother and requiring of less pedal effort.

 

hth

Thanks for the long and complete reply! My apologies for the short opening post, I was quickly typing it before I had to leave which is never a good idea.

The car has had no recent work to the clutch or braking system. The fluid was last replaced last year.

My clutch is using hydraulics indeed. I have checked the fluid level again today after standing still a couple of days in the garage now and it's still perfectly at the same level and no hydraulic fluid underneath the car.

Because it started so sudden, I don't expect the problem being a swollen hose and pumping multiple times also doesn't make any difference.

A broken pressure plate spring could definitely be the problem, is there a way to check that without having to take the clutch out of the car?

That was the first thing that came on my mind as well, but unlike the E9 I can't see the springs under the pedals. The pedal box is only accessible from underneath the car I believe?

Hi

My clutch started feeling very soft suddenly while driving. It almost needs no force but still works perfectly! There's no loss of brake fluid neither, reservoir is still topped up. This makes me believe there's no leak but I'm still puzzled what it could be...

Thanks for you replies!

So suppose it's the pads, should just replacing them fix the problem?

I've never been so thrilled to try out some advice!

I don't remember remarkably more dust on one of the wheels (just washed it) but it might be possible.

Would swapping the pads from the left wheel with these from the right wheel be a possible fix if that's the case?

@Tzei I will be checking the bearings as well asap, thanks!

What kind of noise? Squealing? Scraping?

Is your caliper hitting the wheel. Some 3rd party wheels are not compatible with the stock calipers. Try hoisting the corner and spinning the wheel. Listen for interference. If you hear interference, remove the wheel to determine where it's touching. You can grind the corner of the caliper A LITTLE BIT.

Any pulling when you apply the brakes? Any heat in the wheel after a drive? Sticking caliper piston?

It's a squealing noise. The caliper is not hitting the wheel (I have the E21 alpina style 13" wheels, they have enough clearance) since the noise was also present when I removed the wheel and turned the brake disk manually.

The car is pulling to the left a very little bit (barely noticeable), but both calipers are coming out nicely. The calipers have been renewed 2 years ago, the disks about 1 year ago.

Actually yes it does. Takes some of the excess play off hence no noise.

Okay, didn't realize that. How can I check if it's the bearing?

Could it be the wheel bearing?

It's certainly the brake. When i took the pads out and turned the weel, the noise was gone. Also, I belive hitting the brakes wouldn't stop the noise if it was the bearing?

Hi,

Since a couple of months there's some noise from my brakes while I'm not braking, as soon as I brake it's gone. I traced the noise down to the right front brake. Since it's a sort of on/off noice going faster with the speed of the car, I suspect the brake disk isn't 100% straight anymore. Problem is, the brake disks are replaced recently and haven't even done 10000km yet. I'm afraid replacing the disk will have my ending up in the same situation after a couple of months. Any ideas how I can stop the noise or solve this issue in another way?

I have already tried removing the sharp edges from the brake pads and disks with no result.

Thanks for your replies!

Laurent

We need a European contact to buy them for us, and ship them over.. might be worth it..? Warranty might be tricky..

I could do that for you, but what difference would it make? If the package I send you is checked you will have to pay import duties I'm afraid...

I'm curious if those European dealers are allowed to sell in the US...if so, it would be a slam-dunk deal at those prices.

MidAmerica would be a good place to have a tech session for the 123. We could install it into someone's car to show how easy it is...and how great they are.

Ed

They're probably allowed to sell, hower US people risk to have to pay import duties I think... Inside EU no duties of course!

Bought mine here: http://www.brits-n-pieces.com/home.aspx

Few dollars cheaper also kind contact...

Guys, now im seriously thinking if I should mount my 123 before I even wake mine up from winter snore

Sure you should!

http://www.leenapk.nl/123BMW.html?language_code=en(thumbs up)

Bought mine there as well, recommended seller!

You won't regret it!

You can easy use brake booster vacuum... You can give aditional T-link and smaller one use for 123ignition. But you should use damper to even your vacuum pulsation...

Le Tran pointed out that the Ireland side draft manifold is drilled between runners, and that works to stabilize the pulses AND it has threaded holes in the middle-bottom, for a connection.

Well, mine are PHH and no DCOE and afaik I have no vacuum on the carbs. I also don't want to tap the manifold because the sidedraft manifolds for 1600 are very hard to find in original condition. On the other hand, I don't have any problem with my current setup without vacuum and the 123. Should I add vacuum to the 123 with these spacers?

Great topic! As Zinz mentioned, I have an 123 as well. Why not share my experience with it?

I bought mine in august, and installed the 123 with a curve from another 02 enthousiast (posted by Zinz a couple of posts earlier). Never changed much about it as the car was going great with this setting and no static advance. Dyno resulted in 90hp with a stock 1600 motor with dual Solex carbs, everything ajusted as it should. Not bad at all so I wasn't triggered to change much.

When Zinz asked about my experiences with the 123 we started brainstorming about things to try out, just by talking about the settings we had, and things we might have to try out. Since then my car has improved quite a bit. To keep the long story short, static advance is now at 10°, but I retarded the curve by 2-3° above 4000rpm as the car was running hot when I kept driving at approx 5000-5500rpm in fourth gear (did that on a safe, wide, straight, empty road for testing purposes only, of course).

I tested the curve and static advance settings (and a lot of others as well) with the tuning tool included in the 123 software. I always used the same piece of road and did multiple measurements in both directions with the same settings, and then took the average (pretty scientific right?). I haven't put the car on the dyno since then, but I really feel the car is driving at its best now, compared with before the 123, well, it's a whole different car actually! If there's anyone doubting about an 123 out there, just order the thing right now!

Is there anyone on the FAQ who has these bumpers and can confirm the nice quality and fitment?