Brake Master Cylinder options

[Thomas76]

I didn't come up with a solid solution by searching on our trusty forum so I hope that doesn't give me my answer...
On the early couple with bigger booster and smaller diameter master cylinder arrangement do we really need to spend $250 for a new one? I'm a bit shocked this is so high. Would not be afraid of a rebuild kit but prefer a new one. I don't see a rebuild kit out there anyway.... Anyone have tips out there?

 

[HB Chris]

The earlier coupes had the thinner pancake style with 23.8mm master, later coupes had the larger booster with 22.2mm master.

 

[Ohmess]

Rock Auto has one: https://www.rockauto.com/en/catalog...e+&+wheel+hub,master+cylinder+repair+kit,1840

 

[Ohmess]

Oops. My mistake, later booster only. However, if you click on that link and then on the Raybestos part number, it will give you a list of all the cars that used that same brake master. Maybe you could find an Alfa or a Volvo part.

 

[Thomas76]

Still scouring the internet hoping for something solid, Master cylinder prices are all over the place ranging from $210 on Rockauto to $500 on another site.
So far the rebuild kits look like a guessing game as to bore diameter and what parts come with it. W/N has a RHD rebuild kit, and I still don't see why the heck internals would change between RH and LH drive cars...

 

[HB Chris]

This is the correct 22.2mm master:

ATE 34311120479, 010148 Brake Master Cylinder - BMW

Find ATE, 010148 Brake Master Cylinder 34311120479 at discount prices in our extensive BMW auto parts catalog. AutohausAZ offers a large selection of ATE parts online. Fits BMW 3.0CS, 2800, 2500. 010148

www.autohausaz.com

 

[jmackro]

This is the correct 22.2mm master:

ATE 34311120479, 010148 Brake Master Cylinder - BMW

Find ATE, 010148 Brake Master Cylinder 34311120479 at discount prices in our extensive BMW auto parts catalog. AutohausAZ offers a large selection of ATE parts online. Fits BMW 3.0CS, 2800, 2500. 010148

www.autohausaz.com

OK, so Thomas76 question might be revised to: "do we really need to spend $219 for a new one?" I guess AutoHausAZ has the right part, but its price is still pretty staggering. But, I guess if rebuild kits aren't available, and it's your brakes that we're talking about, there isn't much alternative.

 

[mulberryworks]

Still scouring the internet hoping for something solid, Master cylinder prices are all over the place ranging from $210 on Rockauto to $500 on another site.
So far the rebuild kits look like a guessing game as to bore diameter and what parts come with it. W/N has a RHD rebuild kit, and I still don't see why the heck internals would change between RH and LH drive cars...

RHD cars have two master cylinders in series, so they could be very different. Lack of room is the reason, I think.

 

[Thomas76]

I forgot to update this post, I ordered a new one from Rock auto 13034001 and cost $230 shipped. This was a quality piece made by Centric, however the casting is ATE. This could suggest they are taking old castings and rebuilding them in the factory? Either way problem solved and wasn't quite as expensive as I feared. Hope this helps!

 

[HB Chris]

Centric is a rebuilder

 

[Cornishman]

Glad it is fixed now, but just for info.
The RHD uses a master cylinder to feed two separate supplies to two remote servos. The reason for this vs LHD is the space and exhaust manifolds that sit in front of the driver on a RHD.
I can’t imagine that the internals could be the same between LHD and RHD.
If you think LHD master cylinders and servos are expensive take a look at the RHD parts prices . However the upside is that we don’t need to drive on the wrong side of the road

 

[Stevehose]

All the usual suppliers under $300 for 34311120479 are out of these, any other options? I have a rebuild kit on order from E. Europe but who knows how long that will take.

 

[Thomas76]

$212 in stock, rock auto dude!


RockAuto

 

[Stevehose]

I show the Centric part number for 1972 3.0cs as CENTRIC 13034004, your link is for 2002 Tii ??

$212 in stock, rock auto dude!

RockAuto

 

[Thomas76]

Hmm, I do have a 1970 with the early booster. Not sure about crossover with 2002 master. It is installed and is road tested, works good on my whip. Dimensions matched my old one.
Sorry if this is turning out to make your sourcing more complicated.

 

[HB Chris]

34311120832 23.8mm pancake booster
34311120479 22.2mm large booster

 

[Stevehose]

All good, appreciate it

Hmm, I do have a 1970 with the early booster. Not sure about crossover with 2002 master. It is installed and is road tested, works good on my whip. Dimensions matched my old one.
Sorry if this is turning out to make your sourcing more complicated.