So I replaced my M roadster clutch line today

[Tib]

Ralph

I also enjoy reading your posts, I think this has made a very informative DIY.

Here is the tool I was looking for unfortunately it does not seem to be currently in manufacture for the e36 anymore.(BMW 90.88.6.215.030)
[IMG][/IMG]

That being the case: I think this one will suffice. http://www.bavauto.com/fland.asp?part=cbt+tool

[IMG][/IMG]

I also think while your there this might be a good tool to use if it can still be found for sale.

BMW 90.88.6.212.080 clutch thickness gauge (put it in the hole where the slave cylinder normally resides, gives you a rough measurement without removing the transmission)

[IMG][/IMG]

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Something you will really like about the UUC line is that it is designed to replace that little hard line also. It also has the convenient hex wrench fitting.

http://store.uucmotorwerks.com/stain...-s54-p318.aspx

This is the UUC line I just got it does not have the fitting on the end
[IMG][/IMG]

[rf900rkw]

I've used a C clamp to compress the slave. But it's such a PITA to get seated correctly that I do all air purging on the bench now. Once the slave is air free, you can bleed all you want as long as you don't reintroduce air.

That clutch wear tool looks like an expensive exersize in futility. As the disc wears, the arm will more back. As the nylon pivot wears, the arm will move forward. I can see having a worn down disc and a nubbed pivot combining to read like a new clutch. And this is not to mention the self adjusting clutches introduced with the E46.

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Oh, and removal. Fill the reservoir to the top. A 14mm open end wrench on the line positioned so it's wedged against the bellhousing. There is enough torsional spring in the lines to find the place this happens best. Then a 7/16 or 11mm crowsfoot line wrench on a 12" extension from the top. Crack it loose, then spin it apart from underneath and cap the line. Northern Tool sells the crowsfoot line wrenches, both individual and as a set. Harbor Freight, at least my local one, doesn't have these.

[the alpinweiss]

Installing mine with a friend took right around an hour. The most maddening part is not letting the plunger of the slave cylinder fall into the bell housing. Ask cloudbase about that job .

I agree with the consensus, clutch feels a whole lot better after the delay valve is removed.

[rf900rkw]

I know it is hard to let go of the forumlore, but folks, the M's do NOT have a delay valve. Never have. They have a hole in the hose that is smaller on one end, but is NOT a restriction. A CDV valve has a oneway flapper valve with a restrictor that is one quarter the size of the M hose "restrictor". All other things being equal (and they are), the M hose flows four times as much as the stock 3.0. On the M, the gains from changing the hose is purely from getting the soft ballooning rubber out of there.

[siwilson]

I know it is hard to let go of the forumlore, but folks, the M's do NOT have a delay valve. Never have. They have a hole in the hose that is smaller on one end, but is NOT a restriction. A CDV valve has a oneway flapper valve with a restrictor that is one quarter the size of the M hose "restrictor". All other things being equal (and they are), the M hose flows four times as much as the stock 3.0. On the M, the gains from changing the hose is purely from getting the soft ballooning rubber out of there.

Agree with the ballooning rubber comment, but have to disagree about the restrictor. The smaller hole at one end DOES act as a restriction, slowing the flow of fluid which slows down clutch engagement. Before I changed mine it was quite easy to slip and burn the clutch if I gave it too much gas as i was coming off the pedal. Never been able to do that since the change. I have been running a braided hose for 9 years now and would not go back to stock.

[Z3MROADY]

I know it is hard to let go of the forumlore, but folks, the M's do NOT have a delay valve. Never have. They have a hole in the hose that is smaller on one end, but is NOT a restriction. A CDV valve has a oneway flapper valve with a restrictor that is one quarter the size of the M hose "restrictor". All other things being equal (and they are), the M hose flows four times as much as the stock 3.0. On the M, the gains from changing the hose is purely from getting the soft ballooning rubber out of there.

I found an old thread on this subject started by E368 S52 back in 09. In his DIY he posted comparison photos of the two clutch hoses. One from an M/3.2 and the other a stock 3.0. I did not take photos of my hoses when I did this so .....Here's his. The 3.0 hose has the larger orifices. Although maybe not to exact scale, the M hose has one very small orifice and one larger. How can the M hose flow 4X greater than the stock 3.0? Doesn't seem quite right.

http://forums.bimmerforums.com/forum...Coupe-Roadster

[rf900rkw]

Because you are not seeing the stock 3.0 CDV with it's 0.04x" restrictor. The hole in the M hose is 0.085".

[Tib]

Comment removed: Unnecessary for the DIY

[cfmistry]

For what it's worth I changed to the UUC braided hose and the the difference was quite drastic. Nothing to do with a "clutch delay" but rather the overall pedal firmness.

[silverstonemkiv]

Well Hope you order the tools from Bavauto long before you need them... Just like everything you order from them or Turner. (Most Orders ship in 2 days or less) should say (Most Orders ship in 2 months or more or less).

I just placed an order with turner for my clutch line hopefully your experience was a one-time thing.

[Z3MROADY]

Because you are not seeing the stock 3.0 CDV with it's 0.04x" restrictor. The hole in the M hose is 0.085".

What if we just compared hose to hose (leaving out it's restrictor). Wouldnt the 3.0 hose by itself allow more flow?

[Tib]

Comment removed: Unnecessary for the DIY

[rf900rkw]

What if we just compared hose to hose (leaving out it's restrictor). Wouldnt the 3.0 hose by itself allow more flow?

Yeah, and you can compare it to a steel line, too. But that's not the point. Stock to stock. CDV to the M hose. People seem to really really want to believe they are the same thing. They are not. Not even close.

[Randy Forbes]

Yeah, and you can compare it to a steel line, too. But that's not the point. Stock to stock. CDV to the M hose. People seem to really really want to believe they are the same thing. They are not. Not even close.

I have to admit, I put the 3.0 hose in my '99 years before I put one in the 01, and I couldn't tell them apart.

[ssbuchanan]

Just going through this thread... my UUC SSCL (same as pictured above) just arrived.
I'm going to get my local mechanic to install this at my next service (I know, I know... I don't actually have a garage at the moment, nor a lot of spare time), so should I just assume he'll know how to do this?

Or are there some pointers I should give him? It's sounding like bench bleeding is the way to go?

[Mr Bingley]

Print out this tread for him. Most professionals don't like it when non-professionals tell them how to do their jobs, but a good one should always be open to new information that might make their job easier--tell him its in the "for what its worth category." Certainly Randy's comments will interest him.

[rf900rkw]

I have to admit, I put the 3.0 hose in my '99 years before I put one in the 01, and I couldn't tell them apart.

My original thing up there, I was comparing the original M hose restriction to the original 3.0 restriction. i worded it poorly as usual, such that it could be thought I was comparing bare hose to bare hose.

But anyway, 3.0 vs M hose. The diameter is not a linear limiting factor. There is a flow rate at which the restriction starts to have effect, you overwhelm the capacity of the orifice. The comparison I made the M being four times the flow of the 3.0 CDV. But what is the difference of the M vs an open hose, 3.0 or braided? If there is any difference, it will be in a "free-fall" clutch release, a side-step. Maybe. It's certainly not something that will be felt toodling around town.

[Mr Bingley]

But if you bench-bleed the slave and line assembly fully, and have a full system that was capped, there will be no air. All you do is pull the cap off the hard line and offer up the assembled line and slave. Yes, a bit of fluid will run out, replaced by fluid from the reservoir. No air will get in as long as you don't empty the system. No further bleeding required. If you then want to flush the fluid, you can do so without risk of introducing air. -

Hi Randy, for the benefit of clarity and completeness for this thread as a DIY tool, can you describe how to bench bleed the slave?

[rf900rkw]

Many OEMs have moved to pre-bled clutch hydraulics. The slave comes pre-filled. The master comes with everyting from the reservoir to the slave line, all pre-filled and bled. They use a dry-break connector between the two sides. Many of these systems don't even have a bleeder. Believe me, I often hear how "stupid" this system is from techs that mistakenly let air into the system during a clutch job.

The only difference between those systems and ours is we don't have the dry-break. So if you are slow getting the connection made, you get fluid dripping from your elbows. This, BTW, is why I recommend filling the reservoir to the top.


Connect the hose to the slave cylinder. For the current UUC line, I believe I end up with the hose clocked to about a 10 degree rise. Play with it. Test fit. Once you are happy with the assembly, get a container of brake fluid. If the slave and line are brand new, you can "drink" directly from the bottle. Otherwise, fill something about the size of a dixie cup.

Standing at a bench, hold the slave cylinder with the pushrod pointed down in one hand, hold the hose end pointed up as the highest point in the other hand.

Push the slave down against the bench, compressing the pushrod/piston.

Stick the hose end into the fluid supply.

Let the slave cylinder up, releasing the piston

Pick the hose back up to the highest point

Compress the piston

Put the hose end in the fluid

Release the piston


Repeat. You only have to compress the piston until the is pure fluid in the hose, you don't have to shoot a stream across the shop each time. Repeat until there is no air in the hose at all. At this point you can either insert a plug in the hose end, or go directly to the car and hook it up.

If you want to do a belt and suspenders thing, after all the hydraulic connections have been made, but before mounting the slave, pump the slave SLOWLY a few times with a pause between each stroke. Any minor air at the connection point wil be pushed back into the reservoir. Oh, correct the level in the reservoir before this step.

[jdjkelowna]

What? No $34.95 out-of-stock tool required?

[BenFenner]

I bench bled my master cylinder with my hands. I held the cylinder in place with right hand while my left palm (maybe with some protection) pressed the plunger. The idea of needing a tool to do the clutch slave seemed dubious based on that experience, and now I'm convinced I won't need one.

[rf900rkw]

The tool or a facsimile is needed if you want to bleed the system in the traditional manner. As mounted to the trans, the slave will trap air. You have to remove and turn the slave. The tool then does two jobs. It holds the piston in the bottom of the bore minimizing the air trapping volume, and it holds the piston in so your gorilla pumping the pedal doesn't blow the piston clean into the customer lounge.

[silverstonemkiv]

[QUOTE=Tib;27930212]oh no its a every-time thing with both of them!!

I got shipping info today! you had me worried guy.

[Mr Bingley]

The tool or a facsimile is needed if you want to bleed the system in the traditional manner. As mounted to the trans, the slave will trap air. You have to remove and turn the slave. The tool then does two jobs. It holds the piston in the bottom of the bore minimizing the air trapping volume, and it holds the piston in so your gorilla pumping the pedal doesn't blow the piston clean into the customer lounge.

I did mention the aw s**t moment when I tried bleeding without my homemade bracket...

[ssbuchanan]

Thanks BTW