Matt 123 Report post Posted June 2, 2011 Hi guys, My E30 project is nearly done, the only thing really preventing me going out and enjoying it is that the brakes are performing terribly! I have done a 5 stud conversion so up front it is running E36 M3 brakes and 318ti at the rear. The master cylinder is a brand new 25mm unit from an E32 and it has braided brake lines all round. Basically, the brake pedal sinks most of the way to the floor before anything starts happening and even when you really stomp down hard on them the car doesn't stop anywhere near as well as it should, it's a real "heart in the mouth" moment. We have tried twice to give the car a really good bleed on all 4 corners but to little improvement. The master cylinder was installed following the procedure in the bentley manual which doesn't say to bench bleed it before installing, could this have caused a bit of an air lock? Does it maybe need to be pressure bled instead of the normal 2 man method? Is there anything besides it not being bled well that might be causing it? It is worth mentioning that the brakes were just as bad before any of the 5 stud work was done, ie on the standard brakes, master cylinder and rubber lines. Any advice would be appreciated. Quote Share this post Link to post Share on other sites
hybrid 1039 Report post Posted June 2, 2011 You just need to bleed it properly.. When I took the e30 out for the first time, we hadn't bleed the brakes as we were just testing a few things. It took two pumps to stop the car. The bubbles that came out of all 4 lines where tiny ... but its all it takes. You need to go through a couple of reservoirs worth of fluid. And hold the pedal down when you mate tightens the bleed valve else you’ll get a bubble back in. Quote Share this post Link to post Share on other sites
Nobimmer 694 Report post Posted June 2, 2011 Yeah had the same problem, just needs a real good and proper bleed. I have a really good DIY bleeder I made if you wanna try it, was the only thing that worked for me in the end. Otherwise I can send you a photo. Its really basic but hard to explain :S Quote Share this post Link to post Share on other sites
pureboiracer 0 Report post Posted June 2, 2011 from what ive seen of brake conversions on e30s is that when you use the e32 master cylinder there is a little cap kind of thing that is put into the cup in the master cylinder (that the rod from the booster pushes into.) this takes up the play that is created. (around 4 or 5mm). May pay to whip the master cyl off the booster, (you can do this with the brake lines still hooked up, and check that its there, and before you pull it off check the linkage rods behind the glovebox and see if that is where you have play. Quote Share this post Link to post Share on other sites
smiddy 76 Report post Posted June 2, 2011 Some old school stuff! Jack car as high as possible from rear and start bleeding from LH rear then RHR, LF/RF. Very small amounts of air can create sponge. Quote Share this post Link to post Share on other sites
Matt 123 Report post Posted June 2, 2011 Sweet, thanks for the advice guys. Will try give it another good go tomorrow with the bleeding. Ashkan, if you could send me a pick of your bleeder that'd be awesome. Chur. Quote Share this post Link to post Share on other sites
Gus 5 Report post Posted June 2, 2011 also - good mod is meant to be a brake bar from an e34 as it's slightly thicker and e30 brakes generally suck anyway Quote Share this post Link to post Share on other sites
