Identify Slave Cylinder?

[Nic_s]

Hi guys

I had a look under the 540 to check out the salve cylinder, but all I could see was the number 6634 on the bottom of it and the number 20 on the bit where you connect the pipe.

Is there any way to identify it from that? What does those numbers mean?

The cylinder that I'm suppose to have on the car should have a 24mm diameter.

Info would be appreciated.
Thanks :thumb:

 

[Raybimmer]

I have a cylinder from e36 with 6571 and 20 on it , measured with vernier it is 20 mm inside diameter .

 

[rick540]

Nic.... I think we found your problem.....

Yours needs to be 26.99mm, not 24mm I looked it up. It's exactly the same part as used on the manual E31 850i, E38 740i M60, E39 540i

In fact after going through the entire BMW range, the next biggest one is 22.2mm used on the M5 3.8, so the one used on your transmission is rather unique in that it is an unusually large diameter.

Most BMW's use the 20mm one including my M5, so that would be an easy mistake to make. Where is your old one?

If they fitted a 20mm one instead of the 26.99mm one, it will give you the exact symptoms you are having. (A severely springy hard clutch that slips and some burst pipes.)

 

[Sankekur]

Yours needs to be 26.99mm, not 24mm I looked it up. It's exactly the same part as used on the manual E31 850i, E38 740i M60, E39 540i

Well I don't think it is possible to get a harder to find list of cars.....

 

[Raybimmer]

Rick where did you get the info for ..salve .. cylinder ? Realoem ? Ok had to pull someones leg here .

 

[Nic_s]

Nic.... I think we found your problem.....

Yours needs to be 26.99mm, not 24mm I looked it up. It's exactly the same part as used on the manual E31 850i, E38 740i M60, E39 540i

In fact after going through the entire BMW range, the next biggest one is 22.2mm used on the M5 3.8, so the one used on your transmission is rather unique in that it is an unusually large diameter.

Most BMW's use the 20mm one including my M5, so that would be an easy mistake to make. Where is your old one?

If they fitted a 20mm one instead of the 26.99mm one, it will give you the exact symptoms you are having. (A severely springy hard clutch that slips and some burst pipes.)

I don't have the old one anymore. I don't really have space to keep such things around. I have to many bits and pieces as it is with car parts and PC parts being stored all over. Should really sort it out.

My mechie is adamant that the new slave cylinder is the same diameter as the old one. I can believe that as everything felt exactly the same with the new slave cylinder. So who ever replaced it the first time did it wrong. Why nobody picked up on it I really don't understand.

Because RealOEM lists and auto gearbox for our SA build 6 speeds, I had a look at the Europe version as I remember someone saying that the 2 are close to being the same. RealOEM lists 26,99mm for the Europe spec car.
More here: http://www.realoem.com/bmw/showparts.do?model=HE52&mospid=47384&btnr=21_0006&hg=21&fg=10


So is the number "20" on the cylinder currently in my car it's diameter??


This all means that I've paid for the wrong slave cylinder and then spend another load of cash on a new clutch which wasn't needed as the old clutch is 100% fine. I could have had my 318i fixed up for that money. My mechanic was convinced it's the splines on the clutch that's the problem which, if you look at how the whole system works, makes sens. But he should have checked instead of just assuming. I don't have the proper tools or a descent space to work nor do I know everything and so I entrust my car to someone who's suppose to only to be let down and I'm getting fed up with it. My cars are both pretty old and so I don't expect it to be perfect(How could I?), but I do expect it to be right. How hard can it be to just do something right?? It's pretty much the same in the IT sector. Half the time I'm doing my own work, the other half I'm fixing someone else's. :argh:

This sort of thing happens every time I don't do something my self. Unfortunately, sometimes I just can't. :bangdesk:

 

[Fordkoppie]

I dont know if there are any other sizes , but what if you buy a smaller master cylinder from another e34 that is more freely available?

 

[rick540]

What about swapping out the master on the pedal assembly for one that matches the 20mm slave?

The hydraulics is similar to gearing if the ratio is correct it will work the same.

Smaller slave + bigger master = long throw clutch heavy effort

Bigger slave + smaller master = Light effort short throw clutch

matching slave and master = reasonable effort, correct throw.

I think the only reason for using large master slave combo is to reduce wear and a smaller combo would work and feel the same, it's just an energy transfer device.

If it is a 20mm slave they put in there, just get a matching master out of any E34 that uses a 20mm slave.

(Hint first find the diameter and throw of both original slave and master) and then calculate throw of the 20mm setup and check you get the same master/slave ratio.

__________________________________

Or just go buy the right part

 

[Nic_s]

I went to the mechie who fitted the slave cylinder and got the part number for the cylinder that's in the car now: 31222002

He spoke to the people he got it from (I forgot their name again :facepalm: ) and they say they only have the one cylinder on their list for the entire E34 range except the 540. So as far as I'm concerned it's the wrong cylinder that's in the car.

I'll be getting the right part. I've already been to masterparts to see if they have a Febi part, but they don't. Although I haven't been to the local stealer yet, I doubt they'll have it in stock and will probably charge a lot for it. So will most likely order from the states which should be faster and cheaper.

Will update.

 

[Fordkoppie]

What about swapping out the master on the pedal assembly for one that matches the 20mm slave?

The hydraulics is similar to gearing if the ratio is correct it will work the same.

Smaller slave + bigger master = short throw clutch heavy effort

Bigger slave + smaller master = Light effort long throw clutch

matching slave and master = reasonable effort, correct throw.

I think the only reason for using large master slave combo is to reduce wear and a smaller combo would work and feel the same, it's just an energy transfer device.

If it is a 20mm slave they put in there, just get a matching master out of any E34 that uses a 20mm slave.

(Hint first find the diameter and throw of both original slave and master) and then calculate throw of the 20mm setup and check you get the same master/slave ratio.

__________________________________

Or just go buy the right part

Fixed if it is the clutchpedal you are referring to :thumbs: