944/924 Master Cylinder ?

[Pillow]

Hi everyone,

Pardon my ignorance on this question but is a 924 and 944 master cylinder the same?

I know they are both aluminum housings but not sure of any similarities from there.

Also is there any MC rebuild kits available for either car? I do not see any listed by Pelican.


Thanks,

[Obin Robinson]

no, they are not the same. the one in my 924 is actually a 928 one!

rebuild kits?

hmm,
what year car and which model?

obin

[Pillow]

I was afraid of that. With the 924 having rear drums and all that good stuff.

The MC would be from a late 70's 924... Or I could get a mid 80's 944 MC...

It is for an oddball project but I am leaning to the 944 in the long run because it was designed for 4 wheel disks. Granted in the short run it will be a early 944 front disk and rear drum situation, but later convert to early 944 rear brakes.

The main reason for the question was that a 924 MC is local and cheap I am figuring that the 924 MC has a rear drum check valve as well which would not work with rear discs. Also the brake fluid being displaced to the wheels is probably different.

... Let me refine my inquiry a little based on the previous information:

Is there MC rebuild kits for the early 944? Like '83-'85?


Thanks,

[Obin Robinson]

Pillow,

not all 924s have rear drums, bu most of the early ones do. mine has the rare M-471 option, which is all discs (bigass ones too, this thing brakes like you hit an arrestor hook on an aircraft carrier). 930 rotors up front, and 928 in the rear, 928 rear calipers, and oddball 944/924 turbo ones up front, 928 master cylinder and brake booster.

rebuild kits? hmmm... send me the VIN off of the 924 and i can tell you which master cylinder you can use. or... short answer...

part # 171.698.181L : brake master cylinder rebuild kit for master cylinder 477.611.015A

this was superceded by an entire master cylinder (no more rebuild kits available)

part # 477.611.015A is a replacement master cylinder for the 924 with drums in the rear. it's a Teves part.

if you need more info, don't hesitate to ask!

obin

[Pillow]

Dang Obin! Sounds like you have done this before

I should probably bite the bullet once and just go with the early 944 MC... Or is the 928 MC more advisable?

This application will have no vacuum assist. I was thinking the 944 with the 22mm diameter would be the best bet. Not familiar enough with the 928 MC to know what diameter the piston is.

My other alternative is a new Brazilian VW Transporter MC used from 71-79. They are designed for disc/drum applications, but they are bare steel and rust instantly Plus once rear discs are added this MC would be obsolete anyway due to the drum check valve... Unless you like the rear pads to constantly drag with 2lbs of pressure?


Thanks,

[John_AZ]

I have rebuilt the MC on my 88-924S 51k miles. To add to the senior members comments: I would remove the MC and inspect for pitting where the cups rest. You may have to buy the entire MC.

[Obin Robinson]

Originally posted by Pillow
Dang Obin! Sounds like you have done this before

I should probably bite the bullet once and just go with the early 944 MC... Or is the 928 MC more advisable?

This application will have no vacuum assist. I was thinking the 944 with the 22mm diameter would be the best bet. Not familiar enough with the 928 MC to know what diameter the piston is.


Thanks,

hmmmmmm,

early 944 one or 928 one? hmmmmmmm, that's a good question.

here's the 928 one that is used in my 924:
part # 928.355.011.04

the one in my 944:
part # 944.355.011.01 (ATE manufacture)

i personally would go for the 928 one, but that's just me. i think it is more powerful (but don't quote me on that).

on another note, check this out, this may be an altogether better idea:
http://www.wilwood.com/products/master_cylinders/mastercylinders.asp

if the ratio is wrong, remember you can always get a proportioning valve for those wilwood ones.

good luck!

obin