Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ 914 /6 Master Cylinder Swap

Posted by: dheinz Mar 4 2004, 05:25 PM

The brakes on my 914/6 still feel spongy after a super blue fluid flush and several bleedings.
The car has stainless steel lines, but I do not know how old the master cylinder is. I have access to an 89 911 19mm master cylinder in great working shape.
The question is will it fit without modification.
Eddie

Posted by: davep Mar 4 2004, 05:59 PM

I wouldn't think so. They converted to boosted brakes in the late 70's so the masters are not going to be the same.
How were the brakes before you flushed? The stainless lines can flex also. I still think new rubber lines are best.
Check inside the boot on the back of the master. If it is wet with brake fluid, it is done. A new master should be about $100.

DaveP

Posted by: Dave_Darling Mar 4 2004, 06:31 PM

Sounds like the MC you are thinking of getting is on a car right now. In other words, it's used--just like the one you already have.

My main suggestion is bleeding the system again. Most especially the proportioning valve, but also including the calipers.

Remember, air bubbles rise--so to get the air out, you need to make sure you are bleeding from the valve at/near the top of the caliper! If you bleed from the bottom of the caliper, you'll never get the air out. Uhh, not that I'd know this from experience or anything.... <_<

--DD

Posted by: Andyrew Mar 4 2004, 06:37 PM

I have a new M/c in my car, 19 mm, and new lines and a T for a vavle, but I still have squishy brakes, per to say.. They stop veeeery nice, (thanks to 911 A calipers, and new rotors and pads up front) But I think I bet I need new pads in the back. Check to see if you have good pads as well when freshening up the brake system.

Andrew

Posted by: Van914 Mar 4 2004, 07:39 PM

Be sure to check the rear venting clearance. Too much clearance and you will have a soft feeling brakes. Make sure when you adjust, you use washers and the lug bolt to snug the rotor to the axle.

Van914

Posted by: SirAndy Mar 4 2004, 07:51 PM

another thing i have seen a few times now:

people mount their calipers upsidedown !!!
like, move them from left to right and mount them with the bleeding nipple on the bottom, in which case you'll never get the air out.

i too got the 911 19mm MC new.
don't use a used one, they're not that expensive ...

Andy