Master Cylinder Upgrade after BBK Install?
#16
03-16-2009, 10:29 PM
Ok
Reason I ask is because I had a very similiar issue but not until after I installed extended studs in the rear.
What basically happened is that after I had installed the studs, there is a section of the stud (at the end of the threads) that comes out beyond the hub face. This was preventing the rotor hat from sitting flush with the hub. I fixed the issue by using a different set of studs which didnt have this section protruding out like the other set.
I think k67p67 is on the right track on what to look for for those having this issue.
The pic below shows the section of the stud that I'm talking about. Thought it might be worth mentioning.
Reason I ask is because I had a very similiar issue but not until after I installed extended studs in the rear.
What basically happened is that after I had installed the studs, there is a section of the stud (at the end of the threads) that comes out beyond the hub face. This was preventing the rotor hat from sitting flush with the hub. I fixed the issue by using a different set of studs which didnt have this section protruding out like the other set.
I think k67p67 is on the right track on what to look for for those having this issue.
The pic below shows the section of the stud that I'm talking about. Thought it might be worth mentioning.
#18
03-16-2009, 11:16 PM
I'm glad I'm not the only one with the problem. It is knock back and I only get it after turning. It sucked on the track and autocrossing. But know I know what causes it I will tap the brakes after leaving a corner, since it won't slow me down. You just gotta learn to deal with it I guess, or find out if your hub is flexing beyond normal.
#19
03-16-2009, 11:17 PM
Ok
Reason I ask is because I had a very similiar issue but not until after I installed extended studs in the rear.
What basically happened is that after I had installed the studs, there is a section of the stud (at the end of the threads) that comes out beyond the hub face. This was preventing the rotor hat from sitting flush with the hub. I fixed the issue by using a different set of studs which didnt have this section protruding out like the other set.
I think k67p67 is on the right track on what to look for for those having this issue.
The pic below shows the section of the stud that I'm talking about. Thought it might be worth mentioning.
Reason I ask is because I had a very similiar issue but not until after I installed extended studs in the rear.
What basically happened is that after I had installed the studs, there is a section of the stud (at the end of the threads) that comes out beyond the hub face. This was preventing the rotor hat from sitting flush with the hub. I fixed the issue by using a different set of studs which didnt have this section protruding out like the other set.
I think k67p67 is on the right track on what to look for for those having this issue.
The pic below shows the section of the stud that I'm talking about. Thought it might be worth mentioning.
#20
03-17-2009, 12:23 AM
...saved my *** yet againGood luck and post your findings please.
#24
03-17-2009, 01:03 AM
it just changes brake pedal feel a bit. most of the time they feel really firm (sometimes scary firm), but after a quick turn the pedal travels a little further than usual.
#26
03-17-2009, 11:59 AM
I have a non-sport, '05 5AT coupe and recently installed a 6/4 BBK. I've noticed that in some braking conditions, I need to tap the pedal first to get a firm brake response. This happens maybe 2% of the time, but its usually after hard acceleration or going up a sudden, steep incline. The brakes feel solid in all other conditions.
Anyway, a shop that suggested I upgrade the master cylinder since my brake system now has to push more fluid. This makes intuitive sense to me since after the initial brake tap, the brakes feel great. Have any of you upgraded your master cylinder after installing a BBK?
From talking to other folks here, reading on stoptech's site, and searching g35driver, I've narrowed it down to either knockback, flex in the master cylinder (a brace can eliminate this), or an under-sized master cylinder which is what I'm asking about now. Any additional feedback is appreciated - thanks guys!
Anyway, a shop that suggested I upgrade the master cylinder since my brake system now has to push more fluid. This makes intuitive sense to me since after the initial brake tap, the brakes feel great. Have any of you upgraded your master cylinder after installing a BBK?
From talking to other folks here, reading on stoptech's site, and searching g35driver, I've narrowed it down to either knockback, flex in the master cylinder (a brace can eliminate this), or an under-sized master cylinder which is what I'm asking about now. Any additional feedback is appreciated - thanks guys!
#27
03-17-2009, 04:00 PM
Knock back is very common with many of the aftermarket G/Z BBK's. I have it with my 12-pot fronts. I have had both oem studs and now 50mm Nismo studs, same problem. Some companies include springs with their kits to keep pressure on the pads, some don't and others offer it as an option. I decided not to get them for mine to extend the pad/rotor life a little more.
You have to take care to get all the air out when bleeding the calipers. I used a small rubber mallet when doing mine. In fact I just flushed my brakes again with super blue and found more air after bleeding them twice last year.
You have to take care to get all the air out when bleeding the calipers. I used a small rubber mallet when doing mine. In fact I just flushed my brakes again with super blue and found more air after bleeding them twice last year.
#28
03-17-2009, 10:50 PM
If it was knockback or hub flex, wouldn't you be experiencing this while going though hard turns? I dont' see how hard acceleration or going upa hill would cause this. But during these two specific situations, the engine is experience a great reduction in vaccuum. Maybe the 1 way valve in the vacuum tube is not working correctly? Or your vacuum booster is diff or faulty?
#30
03-18-2009, 08:53 PM
If it was knockback or hub flex, wouldn't you be experiencing this while going though hard turns? I dont' see how hard acceleration or going upa hill would cause this. But during these two specific situations, the engine is experience a great reduction in vaccuum. Maybe the 1 way valve in the vacuum tube is not working correctly? Or your vacuum booster is diff or faulty?
I'll be ordering them shortly.