Geko Posted September 18, 2014 Report Share Posted September 18, 2014 ola, ever since I fitted the brake servo I'm experiencing rear brakes locking which is less than acceptable so I'm trying to find a solution to mitigate of effects of the front/rear brake bias. Has anyone experienced this type of product for regular road/urban use ? Any alternative ? (apart from removing the servo) Thanks Quote Link to post Share on other sites
Tony Millward Posted September 19, 2014 Report Share Posted September 19, 2014 Hi Stef, I use this one from Wilwood, easy to fit and easy to adjust....cheaper than the Moss product...wow. http://www.hawkinsspeedshop.com/brake-systems/wilwood-brake-proportioning-valves-brake-proportioning-valve-knob-adjustment-1--8-in-npt-single-inle.html Cheers Tony Quote Link to post Share on other sites
ctc77965o Posted September 19, 2014 Report Share Posted September 19, 2014 That's odd, why would a servo alter the balance?? Or is it just that without the servo the wheels rarely locked-up. Quote Link to post Share on other sites
Geko Posted September 19, 2014 Author Report Share Posted September 19, 2014 (edited) That's odd, why would a servo alter the balance?? Or is it just that without the servo the wheels rarely locked-up. Hi Dave, without servo I could never predict the locking point which was always earlier or later than expected. With the servo I have a better touch/feel on the brake pedal but definitely the balance is affected. I also suspect multiple causes since I found out that the shock absorber RH is leaking and that the coil springs look weak hence affecting road adherence. So I'm going to attend the suspension first and then go the pressure valve route if no noticeable improvement Edited September 19, 2014 by Geko Quote Link to post Share on other sites
ianc Posted September 19, 2014 Report Share Posted September 19, 2014 Remove servo - unnecessary encumbrance and added weight. But ... one can fit smaller diameter cylinders in the rear brakes, thereby reducing the effectiveness of the rear brakes (but does not reduce the effectiveness of the handbrake, of course). Ian Cornish. Quote Link to post Share on other sites
BrianC Posted September 19, 2014 Report Share Posted September 19, 2014 I agree with Ian, but also don't understand why you have better 'touch/feel' with the servo. I thought servos reduced the feel, much as power steering reduces the feedback from the road. Both simply reduce the amount of driver effort required with consequent reduction in direct feedback. Quote Link to post Share on other sites
Graze Posted September 19, 2014 Report Share Posted September 19, 2014 Hi Stef, I use this one from Wilwood, easy to fit and easy to adjust....cheaper than the Moss product...wow. http://www.hawkinsspeedshop.com/brake-systems/wilwood-brake-proportioning-valves-brake-proportioning-valve-knob-adjustment-1--8-in-npt-single-inle.html Cheers Tony So Tony do i understand, dual circuit, one of those on each, adjust to suit? Graze Quote Link to post Share on other sites
Geko Posted September 19, 2014 Author Report Share Posted September 19, 2014 I agree with Ian, but also don't understand why you have better 'touch/feel' with the servo. I thought servos reduced the feel, much as power steering reduces the feedback from the road. Both simply reduce the amount of driver effort required with consequent reduction in direct feedback. I don't believe so, the more you stretch your muscles to apply pressure on the pedal, the less sensitive/progressive they become towards the maximum stretch. The extreme example is the athlete muscle tear which happen suddenly and without warning Quote Link to post Share on other sites
AlfredHitchcock Posted September 19, 2014 Report Share Posted September 19, 2014 (edited) Some years ago my companys response to excess weight in the boot of our Peugeots was to fit them with caravan coil 'spring assistors'. They were in effect hard rubber blocks fitted between the coils of the rear springs, thereby stopping them compressing. This had the effect of making the rear wheels lock up. I questioned their safety with a Peugeot technician and he said that the rear suspension is designed to squat and transfer the torque loading created by braking into the springs. The Peugeots had a similar pivoting arm/coil spring setup as the 4A. I would guess that overly hard springs would have a similar effect. Do any of you 4A drivers perceive a squatting at the rear when braking? Edited September 19, 2014 by AlfredHitchcock Quote Link to post Share on other sites
Tony Millward Posted September 20, 2014 Report Share Posted September 20, 2014 So Tony do i understand, dual circuit, one of those on each, adjust to suit? Graze No Graze. You only need to fit one to the rear brake line. I fitted a larger servo from a Nissan and rear disc brakes, all work exceptionally well but needed the bias control to adjust the balance as required. With my braking system i have plenty of feel and can outbrake any standard TR6 without lockup. I also have lowered, 420lb springs and Spax shockers on the rear suspension, set how I like them. The car corners very well and feels safe. Cheers Tony Quote Link to post Share on other sites
Graze Posted September 20, 2014 Report Share Posted September 20, 2014 No Graze. You only need to fit one to the rear brake line. I fitted a larger servo from a Nissan and rear disc brakes, all work exceptionally well but needed the bias control to adjust the balance as required. With my braking system i have plenty of feel and can outbrake any standard TR6 without lockup. I also have lowered, 420lb springs and Spax shockers on the rear suspension, set how I like them. The car corners very well and feels safe. Cheers Tony I can attest to the cornering, general look of the car from when you kindly took me for a blast in April Thanks, I now understand, all you are doing is restricting the pressure to the rears Graze Quote Link to post Share on other sites
Tony Millward Posted September 21, 2014 Report Share Posted September 21, 2014 You got it.... Tony Quote Link to post Share on other sites
Marc R Posted September 21, 2014 Report Share Posted September 21, 2014 Hi Tony, Thanks' for sharing the experience, I shall consider this option to better balance the front/rear braking on my Stag. that I use on regular basis. Best regards Quote Link to post Share on other sites
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