Poor brakes

[MKZ7212]

Never been overly impressed with the brakes on my 7 but having never driven another i don't really have a gauge!
i rebuilt the callipers about 5k miles ago and also fitted a 929 master with brake stopper to stop bulkhead flex, still have ABS
using EBC yellow stuff pads which do need a bit of heating up first (going to try ds2500) and groove discs (Cant remember the brand) Motul RBF600 dot 4 fluid
on the last track day i did i was really have to stomp on them but there was no real progressive braking, and i never had the ABS kick in so not sure if that is working correctly!

Going to bleed them again this weekend and read somewhere about having the key switch on to help bleed the ABS pump?

 

[Rehab.pr]

I assume no abs light on the dash? Still the bulb may be blown or missing. Loads of people take them out to rid the dash lights instead of actually fixing the fault grrr.

With regards to key on bleeding, it’s veen hot debate in almost every forum for rotaries I’ve been on, and never has there been a definitive answer. Some say yes you need to key on as this opens the valves in the abs unit to open. Others say on the Rex the valves are always open unless in operation so you don’t need to so if I was you I’d do it key on as there’s no harm in it, see if it improves the feel.

I assume you bench bled the 929 before installing? And also adjusted push rod in servo to reduce free play?

I deleted my abs and was the best thing ever. Added a prop valve and after fine tuning the bias the car brakes beautifully. Of course you need to learn the new braking characteristics of the car and work on your threshold braking if on track....but once you get it, you’d be reluctant to return to abs.

From a safety point abs is great, but from a performance point of view I think without is best. But that’s just my opinion.

 

[MKZ7212]

I assume no abs light on the dash? Still the bulb may be blown or missing. Loads of people take them out to rid the dash lights instead of actually fixing the fault grrr.

With regards to key on bleeding, it’s veen hot debate in almost every forum for rotaries I’ve been on, and never has there been a definitive answer. Some say yes you need to key on as this opens the valves in the abs unit to open. Others say on the Rex the valves are always open unless in operation so you don’t need to so if I was you I’d do it key on as there’s no harm in it, see if it improves the feel.

I assume you bench bled the 929 before installing? And also adjusted push rod in servo to reduce free play?

I deleted my abs and was the best thing ever. Added a prop valve and after fine tuning the bias the car brakes beautifully. Of course you need to learn the new braking characteristics of the car and work on your threshold braking if on track....but once you get it, you’d be reluctant to return to abs.

From a safety point abs is great, but from a performance point of view I think without is best. But that’s just my opinion.

Yes bench bled the MC but I didn’t adjust anything else, will check the play tomorrow

Oh and the abs bulb is good as I put new bulbs in the dash

 

[JoeLanger]

I've never rated ABS on any car, and only ever had it kick in (RX7 included) on extreme wet/icy weather or dirt track all of which you don't need it for. it's almost killed me a few times too, just cuts braking whenever it looses traction on one wheel... bullshit.

Can't help other than that mate!

 

[Rehab.pr]

I think it’s unanimous! RIP it out!!! Haha. Yeah just check the adjustment on the push rod, when I installed my 929 I had to adjust it a fair bit

 

[GAVBEY]

I dont have ABS on my fastroad / track car. and on track you really dont need abs. i have a street car that i was going to keep the abs on but after driving it i think ill take it off anyway. the stock abs is pretty crap in my eyes. your bias valve might be a bit scetchy? 929 master make a massive diffrence in my car for sure. on stock brakes. and on ksports too

 

[MKZ7212]

I dont have ABS on my fastroad / track car. and on track you really dont need abs. i have a street car that i was going to keep the abs on but after driving it i think ill take it off anyway. the stock abs is pretty crap in my eyes. your bias valve might be a bit scetchy? 929 master make a massive diffrence in my car for sure. on stock brakes. and on ksports too

How was it different? As I understood it would be firmer as pushing more fluid
I didn’t get a chance to adjust the push rod but going to try that first. Never heard of the bias valve going bad but I guess that’s possible too

 

[Spendyrx]

Just to add..... I've never touched my brakes, only replaced rear pads 4 years ago with cheapy 15 quid pads. My brakes are great. The only trouble I ever had was doing a 110 down a street, hit the brakes and had a bit of a snakey wiggle on in a straight line!
I drive a saxo though and usually have either saxos or 106s so I'm pretty used to putting my feet through the holes in the floor pan and using my feet to stop ?

 

[MKZ7212]

I assume no abs light on the dash? Still the bulb may be blown or missing. Loads of people take them out to rid the dash lights instead of actually fixing the fault grrr.

With regards to key on bleeding, it’s veen hot debate in almost every forum for rotaries I’ve been on, and never has there been a definitive answer. Some say yes you need to key on as this opens the valves in the abs unit to open. Others say on the Rex the valves are always open unless in operation so you don’t need to so if I was you I’d do it key on as there’s no harm in it, see if it improves the feel.

I assume you bench bled the 929 before installing? And also adjusted push rod in servo to reduce free play?

I deleted my abs and was the best thing ever. Added a prop valve and after fine tuning the bias the car brakes beautifully. Of course you need to learn the new braking characteristics of the car and work on your threshold braking if on track....but once you get it, you’d be reluctant to return to abs.

From a safety point abs is great, but from a performance point of view I think without is best. But that’s just my opinion.

How do you adjust the push rod in the servo?!
i have a spare brake booster and looked at that but it just spins round? (presume you mean the plunger from the servo to the master not the brake pedal adjustment

 

[Rehab.pr]

Yeah you have to take the master cylinder off and behind it the pushrod has an adjustable dome nut on it. You can adjust this in and out to lengthen/shorten the rod.

 

[Daston]

I am going through the exact same thing, coming down hill at around 90, hit the brakes and nothing. Nice firm pedal a lot of swearing and some brown underwear. I then realised just how good the RX handles in the bends lol.

I have changed the pads for some red-stuff ones and did the brake lines whilst I was there. I have been told to check the check-valve in the servo as these sometimes fail causing the servo assist to go. This makes sense as the pedal was solid suggesting I just wasn't hitting it hard enough.

Any idea what sort of pressure the valve should open at?

 

[Nas80]

I changed for racing brake fluid and this made the abs feel like my last FD that i removed abs.

I use project mu pads but I have also had ds2500 and they were awesome. Don't like ebc pads. Think they are garbage.

 

[JoeLanger]

I am going through the exact same thing, coming down hill at around 90, hit the brakes and nothing. Nice firm pedal a lot of swearing and some brown underwear. I then realised just how good the RX handles in the bends lol.

I have changed the pads for some red-stuff ones and did the brake lines whilst I was there. I have been told to check the check-valve in the servo as these sometimes fail causing the servo assist to go. This makes sense as the pedal was solid suggesting I just wasn't hitting it hard enough.

Any idea what sort of pressure the valve should open at?

Dude getting no braking and poor braking are two totally different things.

Could check that valve just blow on it.