23mm master cylinder, out of what??? Options

[stock93]

What car did the 23mm master cylinder that will bolt into our cars come out of?

John

[john rogers]

Early Mercedes. You'll need the alloy front end support or what ever it is called as it is too long for the steel tube one, although I have seen a picture where someone put a dent in the tube with a BFH?

[soloracer]

I believe it was a Mercedes truck. It's an ATE master cylinder. A search of the forum should give you a part number.

[ArtechnikA]

plain ol' Mercedes passenger sedan.

a few places have them (or claim to). i dealt with a couple of places that claimed to have them, but they meant they "could get" them. DART (they advertise in Pano and Excellence) had 'em in stock and will know what you need. you will need to mod the pushrod a little, has to be a little longer or shorter, i don't recall which. you can easily make one out of a cylinder stud by grinding a full ball radius on the 'working' end.

gotta ask: what are you doing to/with your calipers that makes you think you need such a thing? (there *are* correct answers to this question! but it's not something that everybody needs and it is NOT a "standard upgrade" to an otherwise stock brake system - even in a 914.6)

i've heard the stories of suspension crossmember mods too but i know for a fact i did NOT have to do that when i put my Mercedes MC in my 914/6 25 years ago. we'll see what happens when i p[op one into the 911 ...

[john rogers]

I think the 914/6's came with the I-beam type front end support if I remember correctly? The 23mm m/c fits in there okay with that but not the 914/4 steel tube support. When I put mine in the 1973 race car I had to do a replacement. There is also an issue with the front line that feeds the brake fluid from above that it hits the bottom of the gas tank and the one I bought came with a short, bent adapter so the lines fit okay. I also had to lengthen the rod from the pedal to the back of the m/c.

[Brett W]

John (stock93) will be my guinea pig for a Volvo brake upgrade. Want to test the 19mm and 23mm masters. Will probably be running Volvo vented calipers on the front and 320 calipers in the rear. Might do all Volvo calipers all the way around.

[ArtechnikA]

QUOTE (john rogers @ Feb 14 2005, 04:11 PM)

I think the 914/6's came with the I-beam type front end support if I remember correctly?

not sure what you mean by the I-beam support, but i did recheck the ETKA and sure enough /4's do carry a different part number for the rear crossmember - i always thought they were the same. 6's get a '901' number and 4's get a '914' number and you can't see diddly squat on the picture, and there's only one and you can't tell which it is anyway...

and i don't have a /4 crossmember to compare... i do recall having to re-twist / re-route the reservoir lines but it was ok with the stock parts in different places.

the aluminum crossmember arrived in "around" 1972 for the 911, "officially" for the 1973 911RS, but not all RS's got them, and not all "regular" 911's didn't. opinions vary as to why. almost certainly the first 500 homologation cars got them at first (lighter) and at least a few of those were refitted as roadgoing cars with heavier stuff. certainly some of the competition cars got the steel members (stiffer)... as for the rest - it was probably whatever was available in the parts bin that day, in the absence of a special order...

looks like my '71 911 carries the same part number as the 914.6 so barring pedal box dimensional differences i may be good to go!

thanks ! i learned something today !

[anderssj]

Brett,

I think that the Volvo 240 used a 22 or 23mm MC with the 4-piston calipers--but they also had a vacuum assist. Wouldn't the 23 give you an awfully hard pedal?

I've got a set of vented volvo calipers and a MC hiding in garage somewhere if you need any dimensions (piston size, etc.).

Lemme know . . .

Best,

Steve A-

[nickg]

the 6 i parted out had a tubular crossmember

[Brett W]

Thanks for the offer. I already have the calipers and stuff. just need the 23mm master.

With the proper proportions the pedal should feel like the stock brakes.

[rj777]

I've been looking at this on ebay for quite a time...the guy seems to sell these regularly...http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7943123843&rd=1&sspagename=STRK%3AMEWA%3AIT
if anyone knows about these what modification for 75 914 1.8

[Britain Smith]

What type of brake system do you think would require a 23mm master cylinder. I have all Carrera brakes on my 912 and I also have a 23mm master cylinder that I have not yet installed. Do you think that this is overkill or would it feel just fine?

-Britain

[stock93]

Britain,
Read Brett W's replys.

Ok guys, I got a mer truck or passanger sedan. I have access to several older Mercedes cars for parts. What does anyone know specifically what model this MC is out of?

[ArtechnikA]

QUOTE (rj777 @ Feb 15 2005, 02:19 PM)

if anyone knows about these what modification for 75 914 1.8

please learn how to use the "http://" button !

ok, rant over...

those look like the same ones available all over, over the counter, and at the typical price. DART isn't going to ask you to wait 21 days for shipment tho...

like it says, and every thread on this subject has said - you will need to clearance the suspension crossmember somehow, or use a 911/914.6 crossmember, or the aluminum 911 crossmember. you are going to have to re-plumb the reservoir lines. you are going to need to change the hard lines to the front and possibly to the first junction to the back. spend the $10 on a brake tubing bender tool and do the job right; brake hardlines are available at every FLAPS. you will need a new, slightly longer pushrod.

you're going to need at least 'S' or 'A' calipers front and 914.6 calipers rear or you'll have a pedal that is impossibly stiff to modulate and has about 1/8" travel, but you'll have spent $200 and a weekend getting there...

this is NOT a standard upgrade.

[Mueller]

QUOTE (stock93 @ Feb 15 2005, 12:58 PM)

Britain, Read Brett W's replys. Ok guys, I got a mer truck or passanger sedan. I have access to several older Mercedes cars for parts. What does anyone know specifically what model this MC is out of?

I still don't get it??

if using the 23mm master cylinder with stock calipers you get what??

bragging rights to your buddies that don't know any better and the joy of spending a few hours under your car?? (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

(IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

[tesserra]

Adding a 23mm MC to a stock system is actually a BAD thing. You get a harder pedal and less pedal modulation of the brakes. Unless you get larger calipers it will be a lot of work for a less desireable result.

George

[SteveSr]

QUOTE (Brett W @ Feb 14 2005, 02:46 PM)

John (stock93) will be my guinea pig for a Volvo brake upgrade. Want to test the 19mm and 23mm masters. Will probably be running Volvo vented calipers on the front and 320 calipers in the rear. Might do all Volvo calipers all the way around.

Brett,

how soon will you have results on the test? I'm working with Volvo calipers also and was not sure what master cylinder to use.

John,

Did you ever get that V6 in your car or did you decide on something different?

SteveSr

[lapuwali]

I'm working up a spreadsheet now to help work out the ratios for MC/calipers. I need the following to finish it:

What is the diameter of one caliper piston on the Volvo 4-piston calipers?
How about the Carrera calipers, Britain? How many pistons are there per caliper?
Mike, what's the size of the caliper pistons on those 4-piston RX-7 calipers you have?

If anyone else has any calipers they'd like added, let me know. I just need the size of one piston and how many are in the caliper.

[Britain Smith]

Carrera calipers (wide-A)

Fronts: 48mm piston bore (2 pistons per caliper)

Rears: 42mm pistons bore (2 pistons per caliper)

-Britain

[Aaron Cox]

Caliper


Piston Diameter

914-4


42 mm

BMW 320i


48 mm

911 - M caliper


48 mm