Hi folks, I'm in the process of upgrading the scirocco's 239mm front brakes and have installed a mk3 golf 9" brake servo. I bought a larger master cylinder (23.81mm) suited for Audi 90 100 that has 4 x M10 ports but when i fitted it to the mk3 servo I noticed there's an inch of free play between the end of the servo pushrod and the master cylinder,when fitted to the scirocco servo its perfect. In the pic you'll notice the difference in pushrod lengths,the mk2 scirocco is on the left and the mk3 golf on the right. Does anyone know of the correct fitting master cylinder for the mk3 ? preferably 23mm or even 25mm version as the callipers have a 57mm piston. 2022-06-07_09-25-13 by Paul Miller, on Flickr
Might be worth trying to extend the push rod? A sleeve perhaps or can it be removed and a length welded on? It would be a good project as many could go with a MK3 servo as MK2 ones are so expensive.
Does the stub pull out like the mk2? Could then extend as @PhilRyder suggests. Or use a mk3 master, or maybe something similar era, galaxy, sharan, transporter etc? Unsure of sizes Skimmed and found https://www.clubgti.com/forums/index.php?threads/mk3-golf-vr6-master-cylinder-upgrade.234996/
yeah i could have bought 3 mk3 servos for the price of a mk2 one! I did try rotating the nipple off the end of the pushrod so I could have a look about extending it but the whole pushrod rotated freely and because the rod is recessed I was struggling to get a decent grip with my not so long nosed pliers so I'm ashamed to say I gave up pretty easily That servo you listed John is exactly what I'm looking for so I'll get one ordered and report back over the weekend hopefully with good news
Mk3 servo fitted and new T4 25mm master cylinder installed. There is a small amount of free play before the servo pushrod engages the master which I reckon is normal? so all looking good. Had to extend the rear circuit to meet the new outlets and in the process of running new front lines ,also picked up a brake fluid reservoir from a T3 at the local scrappy which also has an outlet for the hydro clutch....result. Cheers for the help guys Just noticed I've forgot to put the rubber boot back on the rear of the servo IMG_20220615_151621 by Paul Miller, on Flickr
