Brake issue

**Dewman** · 09-09-2010, 02:08 PM

I am thinking about taking the car to the shop since i dont have much time to work on my car but i want some ideas on what to look for in case its something i can fix in a short amount of time.

My brakes seem to be acting different almost every time i hit the pedal, sometimes they are stiff but very responsive, other times they are squishy and the last option that is the worst is the pedal feels like there is a brick under it. The car still stops then but i almost have to stand on the pedal for it to stop. The car is not throwing any ABS or CEL lights. I have checked the brake booster and it seems to be holding vac. The fluid was a tad bit low but nothing too bad so i added a little more to it. Quick glance at the pads and those seem to be decent (needs a brake job over winter but overall not that bad) Manifold is down tight and all hoses are on tight and car fires on all 8. Car does have an exhaust leak but has had that all summer and this issue has only came about within the past 2 weeks.

Any ideas?

2000 Z28
Cam/Intake/Boltons
55,000 miles

**cammed goat** · 09-09-2010, 04:30 PM

My first question...has the fluid ever been flushed?

**Cutlass** · 09-09-2010, 05:48 PM

I'd have to actually drive the car to be 100% sure, but some of your symptoms seem to point to a bad master cylinder.

**cammed goat** · 09-09-2010, 05:58 PM

I was thinking the same thing. Maybe more time has to be spent diagnosing that master? Just weird.

**Dewman** · 09-11-2010, 08:19 AM

mechanic says he thinks there is a vac leak or somthing because i only am getting 4/in of vac

**Cutlass** · 09-11-2010, 03:44 PM

how big is your cam? Big cams don't produce much vacuum

**cammed goat** · 09-12-2010, 06:03 AM

Originally Posted by Cutlass

how big is your cam? Big cams don't produce much vacuum

Kinda sounds like those writeups in GMHTP where folks have to add a "helper" booster to assist with the braking system after a cam swap.

**Dewman** · 09-12-2010, 07:04 AM

The cam is not the problem, i have been driving it this way for 2 years now and never had a problem. I spent some time yesterday removing small things (valve covers, coil packs, plugs, wires, throttle body,vac hoses) and checking see if it was something else. I didnt remove my intake but i will be doing that in a few days to check that.

Mechanic said worst case scenario is i may have burnt a valve. Not too worried though because i was on the fence about getting heads and that would be the deciding factor.

Mods: (sorry its copy and pasted)
!AIR
!EGR
SLP Lid
UMI Lower Control Arm Relocation Brackets
Magnaflow Catback
FAST LSXr 102mm intake manifold
FAST LSXr 102mm throttle body
FAST Billet Fuel Rails
FAST Stainless braided fuel lines with FP Gauge
COMP Cams hi-tech pushrods
COMP Cams dual valve springs
COMP Cams tool steel retainers
COMP Cams Trunion Upgraded Rockers
COMP Cams LSR 223/232 .610/.617 112LSA
TCI Super Streetfighter 3500 stall torque converter (not installed yet)
TCI Shift Boss Electronic Shift kit
Ebay Long tube headers (not installed yet)
Base tune by Frost