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Discussion Starter · #1 ·
Okay, so i purchased a 2000 pre facelift 323i a couple months ago with a blown engine for 500 bucks, so I swapped a M54B30 into it (originally an M52TUB25). Everything has gone decently well despite the fact that i had to convert the drive by cable throttle to drive by wire, upgrade the fuel filter and pin an additional ignition wire, but right now i’ve run into a wall and i’m frustrated about it and figured someone may be able to help me out.

1. i have a clutch pedal with absolutely no resistance. I’ve tried bleeding it from the slave but hardly any brake fluid bleeds out. it just drips a few times and then... nothing. i replaced the master cylinder because i thought that’s what it was, but no luck.

2. my brake lights don’t turn on when i press the brake, but on my rear window the “third brake light” remains solid without me applying the brakes indicating that the car thinks the brakes are on... the i’ve bled my brakes from all four tires because i discovered that the brake and clutch system work hand in hand through the master cylinder hence the reason i changed it, AND replaced the brake light switch twice. tried a brake light switch from the junkyard, and that didn’t work so i pulled one from my buddy’s e39 that he’s parting out (they are both the same) and still no luck. i’m under the understanding that these brake light switches are magnetic and i’ve tested all of them. they all attract metal the way a magnetic operated device should work....

WHAT THE HELL IS GOING ON?? i’m so unbelievably frustrated... is there anything i’m missing?
 

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I have a 2003 330i with a manual transmission. I replaced the clutch delay valve on that so I know the clutch uses the brake fluid system to operate. Every time you press down on the clutch, brake fluid should squirt out from the clutch pressure line. Are you saying that no fluid came out of the clutch pressure line? My car's setup has a separate brake hose going from the brake reservoir down to the clutch line so the clutch must be using a separate pump to operate, I assume.
 

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In the E39 5-series, one needs to fill brake fluid a bit ABOVE Max so it can get into the clutch reservoir, which is directly partitioned behind the brake reservoir.
 

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Hey guys, so I am the buddy with the E39 he's talking about I have done my fair share of M54 swaps. On my 5th one this summer alone. That being said this problem he's experiencing is strange to me usually when I bleed the clutches in these cars I pump the clutch with the bleeder closed and pressure will build. Hold the clutch too the floor and open the valve and fluid squirts out. With his car for some reason it will only squirt out once, and then nothing else after pumping the clutch. Leave it for two hours and same thing will happen. I've informed nvt that I would like to try to gravity bleed it for a few hours we tried yesterday for about a half hour and it seemed to drip fluid after a few minutes. Thoughts?
 

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Just want to make sure that bleeding the clutch is like bleeding the brakes. I assume you close the bleeder before you let up on the clutch. Then you press down on the clutch again and open the bleeder. With someone having as much as experience like you, this is basic stuff. With that said, and if you made sure the brake fluid level is above the clutch hose's inlet, I am not sure why it wouldn't squirt out the next time. Someone with more clutch experience like @smolck would probably be able to help you.
 

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I appreciate the response. Yes similar to the brakes you pump the clutch pedal with the bleeder closed hold the clutch pedal down open the valve to release the fluid, close the valve, then release the clutch and repeat as necessary. It almost feels like a dead slave to me however I've visually inspected it and it seems absolutely fine.
 

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Center brake light with nothing from the side taillights almost sounds like a wiring harness problem, those parts do have a tendency to short and fail. Is the rest of your taillight assembly functional?
 

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I'm not sure but in my case yes, I will replace that slave. I lack the expertise in diagnosing parts' failure so my approach is usually throwing parts at the problem until it is fixed. Not all is lost because if the new parts do not fix the problem, at least you have backup old but working parts on hand. :)
 

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The master cylinder doesn’t have anything to do with the clutch, your clutch shares a segmented portion of the brake fluid reservoir, but that’s it. You have 2 “slave” cylinders. The slave on the trans that actuates the throw out bearing and one that is attached to the clutch pedal itself (does fail, but it’s rare). I suspect the slave cylinder is your culprit for the dead clutch pedal as it’s a common failure point. As for the brake lights, you have a switch on your brake pedal that actuates the brake lights, I’d start with that. I’d also check your wiring harness connector that goes to the taillights as there was a grounding issue and many of them burn up without an additional ground wire (BMW issued a recall for some E46s).
 

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Discussion Starter · #10 ·
The master cylinder doesn't have anything to do with the clutch, your clutch shares a segmented portion of the brake fluid reservoir, but that's it. You have 2 "slave" cylinders. The slave on the trans that actuates the throw out bearing and one that is attached to the clutch pedal itself (does fail, but it's rare). I suspect the slave cylinder is your culprit for the dead clutch pedal as it's a common failure point. As for the brake lights, you have a switch on your brake pedal that actuates the brake lights, I'd start with that. I'd also check your wiring harness connector that goes to the taillights as there was a grounding issue and many of them burn up without an additional ground wire (BMW issued a recall for some E46s).
Smolck, thank you for the response. I replaced the slave and had the same symptoms for a while but after diligently bleeding it with my buddy brickk it finally got pressure. We're going to continue bleeding it till it's perfect and see what happens after.
 
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