924Board.org

Slam

Mandy's 1980 924 needs a master cylinder. I pulled a good one off the 79 wreck here but the configuration of the stop light sensors is different between the two - the 79 has them both on the underside and the 80 has one underneath and one on the R/H side. Are the bore sizes the same? If they are I'd like to reassemble the one I have (the seals are in great shape) and use it. Both cars are front disc/rear drum.

Ta.

Just did some more homework. All 924 M/C are 23mm bores. Good. So then I should be able to swap over the pressure switches from the 80 into the 79 M/C and install the 79 M/C into the 80 car and be good to go, yes? It seems the difference is in the pressure switches themselves.
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'88 944 Auto - may or may not resurrect

emoore924 · Joined: 13 Apr 2004 Posts: 2822

I think all you need to do is bend an extension for the brake line and extend the wires for the brakelight switch and it should work.

Here's a pic of one in one of my cars...

I have a spreadsheet that outlines every difference between every available m/c but I can't figure out how to post a non-picture file. (If anyone wants to help me out, I'll post it...)

Slam · Posted: Thu Aug 19, 2010 11:54 am Post subject:

Thanks, dude - good pic too, BTW. Thing is, I'm going the other way - 79 M/C into an 80 car. Replacing what's in your pic with the 79 M/C. Maybe the thing to do is just go ahead and do it and report back...

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'88 944 Auto - may or may not resurrect

emoore924 · Joined: 13 Apr 2004 Posts: 2822

Should work np. Just have to change around the brake lines and run the wiring. Same dealie as what you see here, but with the extended brake line going into the passenger side of the m/c instead of the top, and the two switches poking out of the bottom instead of one on the side and one on the bottom...

SlayerSST · Joined: 21 Sep 2010 Posts: 212

Slam · Posted: Tue Sep 28, 2010 1:21 am Post subject:

I didn't go that route. I got a MC rebuild kit from Pelican - I had to do a bit of searching, as the part number is for a 928. After I got the 79 MC apart I decided it was probably a good idea to rebuild the 80 MC instead. What I can do is document the rebuild and provide comparisons between the 2 MCs - first off, according to this site they've got different bore sizes. Right now I'm in no hurry 'cause the 80's put up for winter anyway.
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'88 944 Auto - may or may not resurrect