Welcome to Track Mustangs Online

Join the BEST track enthusiast Mustang community on the web!

Register Log in

Brake issues, will a BOSS 302R ABS help?

domesticpower

Track Addict
Messages
188
Reaction score
131
Location
NS
If I go hard on the brakes, brakes feel very stiff and the car hardly slows down, then they bite hard, then ABS kicks in. I had this issue a few years ago and it only happened after WOT long stints. It was determined to be a bad vacuum check valve resulting in loss of vacuum in the booster under WOT. A new check valve solved the problem. This feels similar but doesn't seem to be always tied to WOT. I also changed the check valve and problem persisted. I'm thinking that maybe factory ABS is struggling with current grip levels so ABS is kicking in and out and I just need the 302R ABS module but don't want to spend the money if it won't solve it (will do that eventually, but there are higher priority items on my list). There doesn't seem to be a vacuum leak that I can tell but aside from checking for that, any other ideas?

Brakes are all stock with DTC50 pads up front and Ate TYP 200 DOT 4 fluid.
 

Mad Hatter

Gotta go Faster
Messages
2,952
Reaction score
1,390
Location
Santiago, Chile
Had a similar problem (sort of)... But it was with the TC turning on by itself when the car though it was in trouble... A track tune from AED fixed that problem and now all works well with no problems braking etc.... Thats with 315/30-18 R7 tires ..... I would still look for that vacuum leak...
 

domesticpower

Track Addict
Messages
188
Reaction score
131
Location
NS
Had a similar problem (sort of)... But it was with the TC turning on by itself when the car though it was in trouble... A track tune from AED fixed that problem and now all works well with no problems braking etc.... Thats with 315/30-18 R7 tires ..... I would still look for that vacuum leak...
Thanks Mad Hatter. Mind explaining how your problem was like?
 

Mad Hatter

Gotta go Faster
Messages
2,952
Reaction score
1,390
Location
Santiago, Chile
Actually, the pedal problem you have sounds the same as my friends with automatics (not enough vacuum when braking we think), Pedal gets hard and car takes time to react to pressure. Try revving the engine a bit before braking and see if it gets better? If it does you probably still have a leak somewhere...

The problem I had was really just the TC coming on whenever the "brain" of the car thought was about to "crash".... This occurred a lot after switching to slicks (seems to be a common problem).

With a AED track tune TC is eliminated and Braking has been great with the ABS coming on only with lousy track conditions.
 

domesticpower

Track Addict
Messages
188
Reaction score
131
Location
NS
Yea, I figured it was a lack of vacuum. I'll look for a leak. Ordered a new valve too, figured maybe I got a defective one... hope I can find it before the next time attack! Thanks again Mad Hatter.
 

domesticpower

Track Addict
Messages
188
Reaction score
131
Location
NS
I replaced the check valve and the problem is still there. More or less eliminated the possibility of a leak in the process because the car had been sitting for 30+ mins when I pulled the valve and there was still vacuum in the booster. May take the plunge on the ABS module and hope it's that. Any other ideas/suggestions are welcome.
 

TMO Supporting Vendors

Latest posts

Top