205toby 0 Posted July 18, 2007 (edited) Guys, I fitted some 307 HDi front brakes to my car and they are awesome- Except for one thing.. I went and did a track day last weekend and found they lock easily- far more easily than the standard 1.9GTi ones. Has anyone else had this problem? I'm using the 205 master cylinder. I think an adjustable proportioning valve may be required. The only reason I can think this would happen is down to the lever effect. The larger rotors mean the pads clamp further from the driveshaft thanm the 1.9 brakes and therefore will act harder to stop the wheel from rotating with the same fluid pressure. This I understand, but surely the larger volume of fluid movement and thus longer pedal movement would make up for this and they would lock up at similar points? Anyone who has had or solved this problem let me know! Cheers, Toby Edited July 18, 2007 by 205toby Share this post Link to post Share on other sites
SPGTi 2 Posted July 18, 2007 Anyone who has had or solved this problem let me know! Changed back to std calipers and discs with Carbon Lorraine pads, 5.1 fluid and braided lines. IMHO feels much, much better. I didn't like the 307hdi setup mainly for the reason you say, they lock up way too easy. Steve Share this post Link to post Share on other sites
kyepan 291 Posted July 18, 2007 which master cylinder are you using, I kept the standard 1.6 one on, and while there is a bit more travel its good for progressive braking and reasonably controllable. Share this post Link to post Share on other sites
205toby 0 Posted July 18, 2007 1.9GTI master cylinder. I think I'll just put an adjustable valve in the rear lines to prevent lock ups. Toby Share this post Link to post Share on other sites
Alastairh 47 Posted July 18, 2007 Do you still run rear compensators. Usually you ditch them when you do this mod. Share this post Link to post Share on other sites
205toby 0 Posted July 18, 2007 Still running rear compensators. What exactly is the benefiet in ditching them? Toby Share this post Link to post Share on other sites
Anthony 1,003 Posted July 18, 2007 Still running rear compensators. What exactly is the benefiet in ditching them? More braking force at the rear, helping to bring the brake balance back to something closer to standard (fitting bigger front brakes will have moved the bias forwards, which won't be helping the locking up situation). As a bonus, it means that you no longer have the failure-prone 1.9 compensators to battle with more MOT's than not... Share this post Link to post Share on other sites
matty_gti 20 Posted July 18, 2007 More braking force at the rear, helping to bring the brake balance back to something closer to standard (fitting bigger front brakes will have moved the bias forwards, which won't be helping the locking up situation). As a bonus, it means that you no longer have the failure-prone 1.9 compensators to battle with more MOT's than not... If puting the 307 brakes on a 1.6 model (with 1.9 hubs) would you still need to remove the rear compensator? Share this post Link to post Share on other sites
Alastairh 47 Posted July 18, 2007 Yeah basically. Myself and Anthony have the same setup on his 309, and my brothers white ex Mi. Basically, running 266mm front brakes, 1.9 master cylinder and de compensatored at the rear. I've driven both cars for quite a few miles, and works spot on. And both went through a mot recently perfectly fine. I know Higgy on here did the same when fitting his GTI6 brakes (practically the same to the 307) and hes happy with it. Worth having a search through Higgys threads, as i know he went into detail etc. But its certainly a good thing ditching those compensators Alastair Share this post Link to post Share on other sites
Henry Yorke 269 3 Cars Posted July 18, 2007 I have 266mm brakes on the standard 1.6 3 way master cylinder and a T'd off rear. The 1.6 compensator is still in the engine bay and the braking is fine for me. Share this post Link to post Share on other sites
205toby 0 Posted July 19, 2007 Next question: Where exactly are these compensators? I thought they were under the rear of the car the same as the early Renaults? Are the peugeot ones load sensing like the Renault ones? Cheers, Toby Share this post Link to post Share on other sites
Anthony 1,003 Posted July 19, 2007 Next question: Where exactly are these compensators? I thought they were under the rear of the car the same as the early Renaults? Are the peugeot ones load sensing like the Renault ones? 1.9 compensators are just in front of the fuel tank under the car, one per side. They're simple pressure-limiting valves with no load sensing. (the exception is ABS equipped cars, where the compensator is on the drivers side of the rear beam, and is load sensing) Share this post Link to post Share on other sites
Anthony 1,003 Posted July 19, 2007 If puting the 307 brakes on a 1.6 model (with 1.9 hubs) would you still need to remove the rear compensator? You never *need* to remove the compensator, but if you want to then you can remove it on both 1.6 and 1.9 models when you fit larger front brakes. Share this post Link to post Share on other sites
