Brake problems, after 272 Camshaft

[88SuperETABD]

Okay, so i've noticed that since i did my e2i+272 cam...my braking performance has dropped greatly...I'm not braking as fast as normal...it feels as if my brakes arent "Grabbing" the rotor as hard as they used to...first step i know is going to be to see if there is air in the lines by bleeding the brakes...lets stay that doesnt work...i was thinking rebuild kits for the calipers. But what i noticed...is my car brakes better at higher rpms than it does with it in neutral...which makes me think its a vaccuum problem or a brake booster problem...any info on this would be great..now that its raining...i feel i should fix my braking problem...

[James]

You need to change the brake camshaft to match the lift of the engine cam shaft.

[Wh33lhop]

I didn't think the 272 had enough overlap to really reduce vacuum at idle, but I suppose it's possible, and that would explain your symptoms if the booster isn't getting enough vacuum... anyone know the cam specs offhand?

Also, do you have a check valve on your booster? Try replacing it.

[Mossman]

The 272 is a relatively mild cam compared to the 288's and whatnot that some people run, and Ive never heard anyone complain about braking issues with those. Anyways, the solution I think is going to be to run a "vacuum reservoir" or "reserve tank" on the booster side of the check valve I would think, so you have more assisted breaking before you run out of "good" brakes. Whenever you're at higher rpm's it will charge up and presumably once you slow down you'll need to rev again before you get going fast enough to really need brakes again.

[Jaxx_]

check for vac leaks. It's possible you ripped out a hose without knowing it and forgot to put it back on when you did the swap.


does the pedal feel firm after a few pumps when the car is off?

[nando]

yeah something is wrong with your vac system - something is leaking. you shouldn't notice any difference, even the bigger cams don't have a problem with vacuum.

[88SuperETABD]

does the pedal feel firm after a few pumps when the car is off?

yes....gets harder after every pump

[88SuperETABD]

And how often should calipers be replaced? It says its a must for track cars...and even old street cars...i'd imagine they would need a rebuild after 275k+ miles on a 21 y/o car like mine...

[nando]

you can rebuild them pretty easily, kits are around $20. they're extremely simple to do.

[88SuperETABD]

you can rebuild them pretty easily, kits are around $20. they're extremely simple to do.

i know that...i'm saying WHEN should calipers be rebuilt...relatively...

[nando]

when they leak or they seize up.. I don't think they really wear

[Jaxx_]

yes....gets harder after every pump

my money is on vac leak. check all your hoses for rips.

[88SuperETABD]

alrighty...will do tomorrow...my mind was set on completing my front end...got air ducts + lip on freshly painted :)