Brake pedal feel after bleeding

InterlagosMC · Post by **InterlagosMC** » Tue Jul 11, 2023 11:03 pm

I’ve just finished a few large jobs on my M which included all new pads, new rear discs and all callipers rebuilt. I have since bled the system through with a pressure bleeder and then used ISTA to bleed the abs pump through but my issue is I still feel that the pedal has a bit of dead travel before the brakes bite. When I watch reviews people always say the brake pedal bites instantly which is what I want but I’m beginning to think it’s not possible on these cars with the stock brake setup. If anyone can confirm either way or has any advice please let me know.
Thanks

maupineda · Post by **maupineda** » Wed Jul 12, 2023 4:21 am

I never had good pedal feel with the stock system. I always wondered if my car had something wrong but after bleeding it several times, it never improved. Then I put some Brembo’s on and now feel is ver nice.

InterlagosMC · Post by **InterlagosMC** » Wed Jul 12, 2023 8:30 am

My old e92 felt really good by comparison for instant pedal bite, even the van I drive for work has a much better initial feel. I just assumed I had done something wrong considering any review I watch state that all pedal controls are instant which I would believe includes the brake pedal but good to know it’s not just mine.

insider · Post by **insider** » Wed Jul 12, 2023 11:41 am

I can confirm pedal feel isn't great even after few bleeds on stock pads. The brake system isn't the best to start with squishy one-piston caliper.

I'll replace the pads in couple of days to endless mx72+. I have hopes this will improve things as pads contribute a lot to brake feel.

If not, then next "stop" will be brembo front calipers as others suggest. Although I feel it's a bit of an overkill for road driving alone... we'll see

InterlagosMC · Post by **InterlagosMC** » Wed Jul 12, 2023 12:25 pm

insider wrote: ↑Wed Jul 12, 2023 11:41 am I can confirm pedal feel isn't great even after few bleeds on stock pads. The brake system isn't the best to start with squishy one-piston caliper.

I'll replace the pads in couple of days to endless mx72+. I have hopes this will improve things as pads contribute a lot to brake feel.

If not, then next "stop" will be brembo front calipers as others suggest. Although I feel it's a bit of an overkill for road driving alone... we'll see

I’m sure my old 3.0si had better pedal feel than the M does, I’m wondering if it’s an air leak on the master cylinder or the brake booster

Argenta · Post by **Argenta** » Wed Jul 12, 2023 2:52 pm

Sure u bled the correct order?
(RR-RL-RF-LF for LHD)
(LR-RR-LF-RF for RHD)

InterlagosMC · Post by **InterlagosMC** » Wed Jul 12, 2023 3:49 pm

Argenta wrote: ↑Wed Jul 12, 2023 2:52 pm Sure u bled the correct order?
(RR-RL-RF-LF for LHD)
(LR-RR-LF-RF for RHD)

I did the initial bleed for RHD as you look at the car from the front bumper as (LR-RR-RF-LF) I did in that order as the brake pipe runs down the right of the car and then goes under the petrol tank over to the left rear making it the furthest away from the master cylinder. The ISTA bleed told me to do it a different way however.

Mr Tidy · Post by **Mr Tidy** » Wed Jul 12, 2023 8:08 pm

That doesn't sound quite right - mine has always felt every bit as good as my 3.0Sis did.

///MC · Post by **///MC** » Mon Jul 17, 2023 2:39 am

My brake pedal was as you described on factory brakes, replaced everything , same pedal feel.
I drove a 997 4s and it made me seriously hate the M pedal feel, hell even an e46 330ci had a better brake pedal.

I put stoptech sport pads, it did improve pedal feel but still no where close to what a sports car should be.

I believe the only solution is a 4 or 6 piston front caliper at least.

ga41 · Post by **ga41** » Mon Jul 17, 2023 8:14 am

///MC wrote: ↑Mon Jul 17, 2023 2:39 am My brake pedal was as you described on factory brakes, replaced everything , same pedal feel.
I drove a 997 4s and it made me seriously hate the M pedal feel, hell even an e46 330ci had a better brake pedal.

I put stoptech sport pads, it did improve pedal feel but still no where close to what a sports car should be.

I believe the only solution is a 4 or 6 piston front caliper at least.

Wont necessarily help... I put Stoptechs 6pot front, 4pot rears on mine pretty early on in my ownership. Brake pedal firmness remained the same as stock but more linear brake feel. I drove an M3 CSL with an AP kit, not sure which one, and the brake pedal was much more firm than mine, i mean no comparison at all.

All else being equal/healthy i think the pedal firmness with aftermarket brake kits has to do with the new piston diameters compared to the OEM ones

insider · Post by **insider** » Mon Jul 17, 2023 9:33 am

///MC wrote: ↑Mon Jul 17, 2023 2:39 am I put stoptech sport pads, it did improve pedal feel but still no where close to what a sports car should be.

Second this! Compared to other sport cars, I can only describe stock brake feel as not confidence inspiring.

ga41 wrote: ↑Mon Jul 17, 2023 8:14 am Wont necessarily help... I put Stoptechs 6pot front, 4pot rears on mine pretty early on in my ownership. Brake pedal firmness remained the same as stock but more linear brake feel. I drove an M3 CSL with an AP kit, not sure which one, and the brake pedal was much more firm than mine, i mean no comparison at all.

This is also my experience - I have 4pots on z3mc and it is better, but still not quite on par. On the other hand, even some single-piston calipers cars can have very good feel with good pads. Hence my current improvement is to mount better non-organic pads.

maupineda · Post by **maupineda** » Mon Jul 17, 2023 3:50 pm

For what it is worth, I have 6-pot e82 performance calipers with 4-pot 996 rears, pedal feel is very nice, firmer and linear, however, they have less bite. based on some basic math I have done, probably the option would be Megane rs front calipers with rear e82 performance calipers. but is a bit of a faff to make e82 rears work on the e86M's.

with the setup I have, there is about 12% less clamping force, I can still engage ABS, or can run more aggressive paths. Overall a good improvement for weekend drives, as neither, stock, nor the e82 setup is really a track worthy setup.

InterlagosMC · Post by **InterlagosMC** » Mon Jul 17, 2023 5:35 pm

Has anyone tried changing the brake master cylinder to better suit the Caliper sizes, I know that brake force would reduce with a larger MC but it would give better pedal feel?

lucasxdiniz · Post by **lucasxdiniz** » Tue Jul 18, 2023 6:38 pm

I know I have ATE pads (assuming they're the OEM), and my brake pedal has pretty much instant bite with minimal travel; when they're hot they grab even harder with very little travel. I drove my old 3.0si and the Z4M back to back and when I jumped on the M, I kept accidently applying more brake pressure when heel and toeing as the brakes are that much sharper than they were in the 3.0si.

Adam D · Post by **Adam D** » Fri Jul 21, 2023 7:57 am

Suspect there is some air still in the system, it may need further bleeding. I had this once when I fitted braided lines on a car where I couldn’t get all the air out of the abs module, triggering an abs activation and bleeding again sorted it but took a lot of fluid passing through to get all the air out.

Stock Z4M brakes and my pedal is firm and strong initial bite.

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