New brakes - wont hold past 5psi

[Dave]

Wellllllllllll what the hell! I just installed new pads and rotors and changed the tranny fluid and filter at the same time. Afterwards when I brake torque it, the brakes wont hold past 5psi.

Before it would hold 14psi. And for some reason it's intermittent. At the track a week ago, it was holding 10psi. Now in the driveway it starts rolling foreward at 5psi.

If it helps any, I've noticed brake fluid building up around the master cylinder caps.

[Mike_Shepard]

Generally brakes need break in time. After driving for a week or so they will be at 100% of braking grip, Mine was the same way

[mcsvt]

Maybe air in the lines? How is normal braking? Possibly time for a fluid flush?
Just ideas.

[turbovanman²]

It will take a week or more of driving to properly seat them. Did you change the size or are they still the stock 10 inchers?

[86lance]

maybe...just MAYBE you should go EASY on your NEW brakes. Dont scorch the damn things just yet.

[TurbododgePirate]

Did you break them in as per manufacturers specs? The heat up-cool down cycle? I did that to my Hawks and have 120K miles on the pads. It boggles the minds of the brake shop.

[Turbodave]

Did you break them in as per manufacturers specs? The heat up-cool down cycle? I did that to my Hawks and have 120K miles on the pads. It boggles the minds of the brake shop.


I have good luck with bedding brakes with a heat-up cool-down cycle as well. The last set of Carbotech brakes on my truck went 75k miles, and I've got about 40k miles on the current set. The oem pads and parts store ones typically lasted about 15k miles for me.

Usually to bed the brakes properly requires getting the vehicle up to 55-60mph and getting on the brakes hard (don't lock them up) down to 5-10mph, then accelerate back up to speed and repeat. I usually do this about 5 times and then park the car to let the brakes cool off. Where I live it's something I can't always do because of traffic, so usually I've got to wait until the middle of the night to do it when the roads are quiet.

[Turbo_Rampage]

If it helps any, I've noticed brake fluid building up around the master cylinder caps.

Thats most likely from you collapsing the pistons on your calipers, and pushing all the brake fluid back up to your master cylinder reservoir when you put the new pads on.. when your brake pads wear down the pistons in your calipers move out more to compensate for the less material on the pads making the brake fluid level low in the master cylinder reservoir, and over time someone usually adds more brake fluid, and thats probebly why your reservoir is overflowing now.

Hope this helps

[Dave]

I did not know you had to break in brakes.

Also, I'm still using the stock 10"s.

[Clay]

yeah, do as TurboDave said. Thats what Ive always done and it works great! I typically do 3 runs from 30 mph -> 5 mph hard (not locked up) and 3 runs from 60 mph -> 5 mph hard, then park it for a while.

[20w/ashelby]

Also I like taking some 200 grit or so sandpaper to my brakes before I install them. They have a shiny appearance when new and I've been told it's very oily.

[Clay]

I always spray everything down with brake cleaner before installing. I doubt there is oil on the pads or they would glaze over. Also, ANY time you install new rotors you have to spray them down with brake cleaner. There is a protective coating on the rotors that will glaze pads quicker than anything if its not removed.

[Dave]

I always spray everything down with brake cleaner before installing. I doubt there is oil on the pads or they would glaze over. Also, ANY time you install new rotors you have to spray them down with brake cleaner. There is a protective coating on the rotors that will glaze pads quicker than anything if its not removed.

Now I dind't know that either! Wow, learning a lot! :nod:

Anyways, I might just take the pads back and get them replaced. There's a lifetime warranty, afterall.

[turbovanman²]

Anyways, I might just take the pads back and get them replaced. There's a lifetime warranty, afterall.


Not for stupidity, hehehehe, :p

[Dave]

Yes, yes there is. ;)

They love me like a fat kid loves cake at Advanced Auto. :thumb:

[Turbodave]

Yes, yes there is. ;)

They love me like a fat kid loves cake at Advanced Auto. :thumb:

They have cake at Advanced Auto? :D

[Clay]

and apparently lots of fat kids

[Ground Rat]

They have cake at Advanced Auto? :D
There is an Advanced Auto? :D

[Ground Rat]

Now I dind't know that either! Wow, learning a lot! :nod:
Don't feel bad, I'm learning a lot in this thread too. :thumb:

[5sp. mini]

any luck with the new head on yet? lmk how it goes, on the brake seating when i put brakes on my bike they rec. to do light stop for the frist 500 miles befroe any hards stops alan

[Boogieman142]

i always use brake clean, some 80 grit sand paper and degreaser and water to clean my pads/rotors and it works great.

[turbovanman²]

If reusing the old rotors, I never touch them, slap on some new pads and you'll put your head thru the windshield.