VR4 Brakes and now Bad Fade with the Brakes while Driving

**Cross** · 1-5-08, 22:55

Ok I did the VR4 upgrade an I thought my MC was going because the pedal goes to the floor and not slowly either. However they are bleed, I even did the whole system and the lines are all SS Front and Rear. I rebleed found air in the rears but then I put on the SS's so thats to be expected. I bleed the clutch the fronts everything in order and still with the new MC pedal to the floor the minute I drive the car.

I can pump it back up, I tried removing the ABS fuse its the same... I am confused!!!

So does anyone have any idea's because i am just lost... I was thinking somehow air in the ABS system or The per portion valve going... the only other thing I can think of is the Booster. Vacuum on it is good I pulled the line and it was under vacuum while the car was off as to be expected.

**ragincanadian4** · 1-6-08, 0:26

The stock MC probably can't handle the extra brake fluid volume associated with the 4(?) piston calipers. Upgrade to a 929 MC and you should be okay.

defiler · 1-6-08, 2:38

Sounds just like he said. Those calipers are huge, and Im sure the fluid volume is quite a lot more than the stock calipers.

02kyle · 1-6-08, 3:28

agree with them on this one

**Cross** · 1-6-08, 3:31

However if you do a search to many have run with the stocker no problems. Its not that I even put in a brand new one for good measure. I already considered that and seeing others on PT who have run this using stock and no problems reported the only thing I have seen is that anyone who indicates says NON-ABS.... I am wondering if its because I have ABS.

This is a few new things I noticed tonight:
1) Brakes will pulse but not all the time, however when they do its very hard even the whole car moves with it.
2) I can pump up the brakes enough that they become firm.
3) When the car is off and right after its been started the brakes are nice and firm as they always were.

**fredio54** · 1-6-08, 6:11

you have bucket loads of air in there.

abs systems should be power bled. they are a bitch to do manually and take ages and a lot of fluid...

also, the title of this thread is "fade" yet you never mention heat at all.... fade and squishy are totally different...

fred.

**neptune_51** · 1-6-08, 20:44

^^ beat me to it on "fade"

I don't have any problem with the pedal going to the floor with my brakes so its probably a given that you have air in the system. Just spend a bit of time with a friend bleeding them. It can take sometimes awhile to do it

**Cross** · 1-6-08, 23:38

Well they have been bleed by a shop and the same results. I am removing the ABS tomorrow and he will rebleed them for free. We think that most who have run these have not had ABS and frankly its not like anyone needs ABS atleast on my end.

So I will remove it after reviewing info here. And then after that rebleed it and see how big a difference it makes. This way when I the bigger 929 MC comes in I can install it and have even better brakes.

Now just to figure out how to get rid of the ABS light as well.... I guess I could say this is also a weight reduction lol.

**Trent** · 1-7-08, 0:38

wait, so you are replacing your ABS, a system designed to pulse the brakes faster than you can, resulting in short stopping distances, with some big flashy calipers and rotors, which will surely lock up on you the moment you stab the brakes.

no offense, but i don't see that as a wise move. You should try to incorporate the ABS before removing it entirely.

Sorry mate, but dodgy brake upgrades have always been a pet peeve of mine, since it's one of the most dangerous modifications one can make to a car.

**Goatcrapp** · 1-7-08, 0:48

anyone giving advice who hasn't actually put on a bigger brake caliper, is (politely) most likely wrong. You don't need a new, larger MC (you may decide you want one later, but its not the cause of this particular problem)

its air. My outlaw 4000 calipers are just as big, if not bigger, volume wise, than those vr4's. I ran them for a long time off the stock MC just fine.

If your pedal goes to the floor as soon as you start it, it means you need to bleed the MC, because you got air in it.

forget trying to do it on-car. bench bleed it. You can bleed it a hundred times through the caliper end, and not get the air out of the MC.

*edit - and X2 on the don't try and de-engineer something like the braking system, simply because you *think* the abs is the problem.

I have abs on my outlaws. the anti lock pulsing happens wayyy before the caliper, so as long as you don't have an abs specific caliper (some newer cars have a abs "flutter" valve in the caliper itself) - which you dont, then abs has very very little to do with your problem. Anyone who has ever increased line pressure by removing abs simply bandaged over a poorly bled master cylinder. Simply deactivating it for track days, you should still be able to lock up no problem.

Make the decision to remove things like abs only AFTER you have a *properly* working braking system. from your description, you are a far ways off.

**Cross** · 1-7-08, 0:48

I agree but I can not seem to figure out why those who have done this before have no problems and I do. After reading more I have just reiterated the fact I do not like this idea... I never wanted to and have been thinking about how much I hate it all day.

The problem is I keep reading about a 929MC being an idea but even in those threads people saying we used the stock MC with no problems... so what the hell is wrong with my setup?

I am pretty much going to return the MC I just bought, return the adaptors I bought because I not only agree but for lack of a better way to say it... [fizzle] not having ABS I did the bigger brakes to stay safe now I am going to remove ABS.... yeah I might as well put stupid on my forhead, even if I know how it works and how to handle myself why remove a safety net for no reason? I knew I could probably handle the change but flat spots in tires, extra annoyances... and damit others are running this setup whats wrong with mine and why do I have to change it....

Yeah I am odd but its def not coming off, your right and my gut was right. ABS is not something to remove. Regardless of how good of a drive you are or think you are, its not hurting you but saving you. I would rather be safer and figure something else out.

**Cross** · 1-7-08, 0:52

Quote:

Originally Posted by Goatcrapp

anyone giving advice who hasn't actually put on a bigger brake caliper, is (politely) wrong.

its air. My outlaw 4000 calipers are just as big, if not bigger, volume wise, than those vr4's. I ran them for a long time off the stock MC just fine.

If your pedal goes to the floor as soon as you start it, it means you need to bleed the MC, because you got air in it.

forget trying to do it on-car. bench bleed it. You can bleed it a hundred times through the caliper end, and not get the air out of the MC.

But we have bled it on a bench already and it was supposedly done again today... why is my car evil... yes its only when we start the car the rest of the time its firm, well I should say when we drive the car with it sitting the pedal feels great too... (I noticed this before ever moving the car today when i picked it up... can't say if I remember testing this again tonight I was fighting with myself for wanting to remove the ABS.... and why the hell this is giving me so many problems.)

I am looking for a 929 MC but honestly... WTH is wrong with mysetup, new MC, bleed so many times its not funny and still the same problem... I agree its air it feels that way but everything I try is not fixing it.

**Goatcrapp** · 1-7-08, 1:06

how are you bleeding? If you're using the two man pump method, it ain't gonna do it.. you need a hand pump or a power bleeder... something that can maintain about 30 hg of vac on the system constantly... and be preapred to use several bottles of brake fluid (might want to take the opportunity to go synthetic also - higher boiling point.)

**Cross** · 1-7-08, 1:08

Already went to dot 4 syn and I used a vacuum pump first then followed with the pump method when I did it.

As for the shop I was told the bled everything sep. and did the whole system but no idea how. I was at work when they did it as they are right next to my work.

**Ryan** · 1-7-08, 2:08

Quote:

ABS is not something to remove. Regardless of how good of a drive you are or think you are, its not hurting you but saving you.

Yeah, ABS can come in handy, unless it comes on when not needed, like when the inside rear wheel is off the ground diving into a corner and the handling character of the car suddenly changes when the ABS activates. But if you don't autocross or track the car, it's wonderful

FWIW, I removed mine.

Where did you get the new MC from? Sure it's not bad, has been bench bled properly?

Aside of that, Fred has it, ABS units can be a bugger, however I'm not sure if ours is the type that must be activated while bleeding to get all the fluid out. It's something worth investigating.

Ryan

1-6-08, 0:26	#2 (permalink)
ragincanadian4 Join Date: Dec 2001 Location: Tampa, FL, USA Age: 23 iTrader: (5)	The stock MC probably can't handle the extra brake fluid volume associated with the 4(?) piston calipers. Upgrade to a 929 MC and you should be okay.
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1-6-08, 6:11	#6 (permalink)
fredio54 Join Date: Aug 2004 Location: Auckland, New Zealand iTrader: (1)	you have bucket loads of air in there. abs systems should be power bled. they are a bitch to do manually and take ages and a lot of fluid... also, the title of this thread is "fade" yet you never mention heat at all.... fade and squishy are totally different... fred.
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1-7-08, 0:38	#9 (permalink)
Trent "Dark Side" of the moon Join Date: Jul 2003 Location: The Mosquito State, LA, USA Age: 25 iTrader: (0)	wait, so you are replacing your ABS, a system designed to pulse the brakes faster than you can, resulting in short stopping distances, with some big flashy calipers and rotors, which will surely lock up on you the moment you stab the brakes. no offense, but i don't see that as a wise move. You should try to incorporate the ABS before removing it entirely. Sorry mate, but dodgy brake upgrades have always been a pet peeve of mine, since it's one of the most dangerous modifications one can make to a car.
	It's a well-known survival tip that you should always carry around a length of ethernet or fibre cable when traveling in wilderness areas. If you get hopelessly lost, bury it. Then you can ask the backhoe operator for directions when he cuts through it. '91 Miata: Turbo.

1-7-08, 0:48	#10 (permalink)
Goatcrapp Join Date: Jul 2001 Location: brooklyn, NY Age: 29 iTrader: (2)	anyone giving advice who hasn't actually put on a bigger brake caliper, is (politely) most likely wrong. You don't need a new, larger MC (you may decide you want one later, but its not the cause of this particular problem) its air. My outlaw 4000 calipers are just as big, if not bigger, volume wise, than those vr4's. I ran them for a long time off the stock MC just fine. If your pedal goes to the floor as soon as you start it, it means you need to bleed the MC, because you got air in it. forget trying to do it on-car. bench bleed it. You can bleed it a hundred times through the caliper end, and not get the air out of the MC. edit - and X2 on the don't try and de-engineer something like the braking system, simply because you think* the abs is the problem. I have abs on my outlaws. the anti lock pulsing happens wayyy before the caliper, so as long as you don't have an abs specific caliper (some newer cars have a abs "flutter" valve in the caliper itself) - which you dont, then abs has very very little to do with your problem. Anyone who has ever increased line pressure by removing abs simply bandaged over a poorly bled master cylinder. Simply deactivating it for track days, you should still be able to lock up no problem. Make the decision to remove things like abs only AFTER you have a properly working braking system. from your description, you are a far ways off. Last edited by Goatcrapp : 1-7-08 at 0:57.
	MX6 #1 [x]Turbo [x]Big Brakes [x]Jspec headlights [x]HID [x]K-Sport Coilovers [x]MSefi [x]Liquid/air I/C [x] 44 kit [x]108mph 1320 [x]oem lip decklid spoiler [x]misc [ ...] done? [x]MX6 #2. SOLD [x]Toyota Paseo. 42MPG. [x]5.9 Jeep. #1's tow vehicle. Still faster than most KL's.//Modifications List

1-7-08, 1:06	#13 (permalink)
Goatcrapp Join Date: Jul 2001 Location: brooklyn, NY Age: 29 iTrader: (2)	how are you bleeding? If you're using the two man pump method, it ain't gonna do it.. you need a hand pump or a power bleeder... something that can maintain about 30 hg of vac on the system constantly... and be preapred to use several bottles of brake fluid (might want to take the opportunity to go synthetic also - higher boiling point.)
	MX6 #1 [x]Turbo [x]Big Brakes [x]Jspec headlights [x]HID [x]K-Sport Coilovers [x]MSefi [x]Liquid/air I/C [x] 44 kit [x]108mph 1320 [x]oem lip decklid spoiler [x]misc [ ...] done? [x]MX6 #2. SOLD [x]Toyota Paseo. 42MPG. [x]5.9 Jeep. #1's tow vehicle. Still faster than most KL's.//Modifications List

1-6-08, 2:38	#3 (permalink)
defiler Banned Join Date: Aug 2006 Location: Coon Rapids, MN, USA Age: 24 iTrader: (9)	Sounds just like he said. Those calipers are huge, and Im sure the fluid volume is quite a lot more than the stock calipers.

1-6-08, 3:28	#4 (permalink)
02kyle Banned Join Date: Nov 2002 Location: columbus,ohio, OSU!!, OH, USA Age: 24 iTrader: (1)	agree with them on this one