Weak brakes

[rkl20678]

I am go karting my 289 with a 351W stroked to an 408 and I don’t think the stock brakes are up to job. I don’t even know who makes the calipers that come with the kit. Trouble is I went with the original 15” wheels with an IRS set up in the back. Very tight on room for calipers.

Anyone have any recommendations on how to get this car stop as well as it accelerates?

Thanks.

[Norm B]

Power brakes.

Norm

[tnt_motorsports]

I would start with bleeding the whole system and bedded the brakes before making too many changes.

[gbranham]

I agree with TNT...make sure you have thoroughly bled the brakes, and have properly bedded the pads. The kit-supplied brakes come from a car 1000# heavier than yours, so they're more than sufficient. You may need to also recalibrate your brain on how much effort is needed with manual brakes.

Greg

[Jeff Kleiner]

You gotta’ bed the pads per the manufacturer’s instructions. Adding power brakes will not improve stopping power….that will just reduce the effort it takes to not stop!

Jeff

[F500guy]

After all that mentioned above, different pads with higher friction is helpful.

[Jim Doak]

I have a similar setup with my build: 15" wheels and IRS. I've driven my car almost 7 miles around our neighborhood go-carting and although I haven't had the opportunity to properly bed the brakes, slowing down and stopping has not been a problem. In fact, it's pretty easy to lock the brakes. Probably the only difference between our setups is that I have vacuum assist. I did notice that stopping power did improve the further I drove, so perhaps you just need to add some mileage to get the brakes bedded?

[BEAR-AvHistory]

I have a similar setup with my build: 15" wheels and IRS. I've driven my car almost 7 miles around our neighborhood go-carting and although I haven't had the opportunity to properly bed the brakes, slowing down and stopping has not been a problem. In fact, it's pretty easy to lock the brakes. Probably the only difference between our setups is that I have vacuum assist. I did notice that stopping power did improve the further I drove, so perhaps you just need to add some mileage to get the brakes bedded?

If it was all on the same trip your brakes got more efficient as they heated up. As a general personal rule with these cars I always check the heat ranges the pads are built for. For street driving you want pads that get effective at a lower temperature than some performance pads.

Have manual brakes & run Hawk 5.0 used to run HPS or HP+

[Jim Doak]

If it was all on the same trip your brakes got more efficient as they heated up. As a general personal rule with these cars I always check the heat ranges the pads are built for. For street driving you want pads that get effective at a lower temperature than some performance pads.

Have manual brakes & run Hawk 5.0 used to run HPS or HP+

It was over three or four short drives around the subdivision. And I'm using the stock pads that came with the kit.

[J R Jones]

You can't test brakes at anything less than highway speed. Your tenative experience suggests the front brakes are not working. Fronts without rears would not be that bad.
You did not mention pulling to the side or one wheel locking, which would make one side suspect. Standard brakes in your light car should be adiquate.
jim

[rkl20678]

24 hours and excellent responses on the forum. Thank you all! Based on your comments I will be a little patient and put some miles on and run them in and then see. The brakes don’t feel soft but I will take another pass and make sure no air is in there. Someone mentioned that my expectations might need adjustment. I completely agree. Finished body goes on next weekend just in time for winter. 14 months since kit receipt. May I have another?

[GoDadGo]

You gotta’ bed the pads per the manufacturer’s instructions. Adding power brakes will not improve stopping power….that will just reduce the effort it takes to not stop!

Jeff

Geeze Sir Jeffski,

I think you told me this when I built Redbone.
Bleeding & bedding makes them work.
Good Luck & Happy Stopping!

Steve

[Cobraman]

As Jeff and all others have said driving and beding the brakes is VERY IMPORTANT. Also brake adjustments front to rear. Once all these things are met as Jeff said in an earlier post your eye balls should pop out of your head when you stomp on the brakes.

[MikeHolt]

I don’t know about the newer version of kits. But, I had to adjust pedal throw on mine. Initial build just wasn’t there. Ended up using all of the supplied spacers.

As for the pads becoming more effective as they warm up…that’s true…to a point! Was on a pseudo track day to Millville, NJ, where our club was doing some spirited “parade” laps. My brakes faded very quickly! Made some of the turns pretty sporting.

[rthomas98]

The other question is how do you have the brake balance bar sat up? A lot of people (including myself) usually has this sat up wrong out of the gate. Mine was way too biased to the rears fixed the adjustment and 50 times better.

[nashuanuke]

The other question is how do you have the brake balance bar sat up? A lot of people (including myself) usually has this sat up wrong out of the gate. Mine was way too biased to the rears fixed the adjustment and 50 times better.

second this, also, the stock brakes just work a little different than you may be used to, i.e. don't expect to be able to lock them up. It takes a little getting used to for some.

[MB750]

I had a similar issue when I started driving my Cobra. Turns out the problem was in my head. I just wasn't used to manual brakes and I wasn't pressing the brake pedal hard enough.

Try this: Get up to 45 mph on an empty, clean, and paved road with warm tires and progressively push down on the brake pedal as hard as you can. If you can lock the front tires up, your brakes are probably fine.

[Jphoenix]

The other question is how do you have the brake balance bar sat up? A lot of people (including myself) usually has this sat up wrong out of the gate. Mine was way too biased to the rears fixed the adjustment and 50 times better.

This is important and can be difficult if you haven't done it before. Also what size masters are you using? Is your pedal soft or hard? A lot of travel or barely any?

I don't recall what comes with the stock brakes. Keep in mind that the stock brakes stop Mustangs a lot heavier than the Cobra.

Get a couple of these - makes bleeding extremely easy https://www.amazon.com/dp/B00F9XHVKA?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

https://youtu.be/jELllXdtjdc