Brake pedal hard to press

[dogginred90]

Ok here is the run down on my new Lumina Z34. The year is 1992 and it has 90,000 miles on it. It has sat for 2 years in a garage with only getting started once in awhile. I was having a hard brake pedal and it took alot to get it to stop. Pulled all the tires and found it needed all new pads and rotors. The passanger side rear slides were completely seized. Fast forward today. All new pads and rotors and still the same issues. Hard pedal and won't stop. Did the whole press pedal while car is off. Start car and the pedal does go down 1/4 distance. Would water in the lines cause this issue or am I missing something?

[Billyvannuys]

Hey Dog: I'm no brake expert, have '92 Vert ABS 76k miles with same issue. Had buddy replace everything except brake lines. He even found some stuff floating in brake fluid reservoir and had lines blown out with high pressure at a brake shop, basically no noticeable improvement. Did you glance into your reservoir with a flashlight to look for contamination? Yeah, mine will. stop, just about as efficiently as Fred Flintstone's Flintmobile.

[dogginred90]

I just finished sucking all old fluid out of reservoir, and replacing with new. Bleed all lines till clear fluid came out. Took it for a test drive and still the same. I did notice that sometimes it works ok (not great) but other times I have to stand on the pedal to stop. I can't drive it long periods of time, cause it hasn't been inspected since 2014. And I still need to do things before it will pass. Next option is vacuum line, check valve, or brake booster

[dogginred90]

I guess after doing some reading, it looks like my issue is the booster. I will do the other tests tomorrow, but still leaning towards the hard to do booster lol.

[Schurkey]

Far as I can tell, brake booster failures were/are epidemic.

 

I went through all that on both of my Luminas, and I'm not entirely convinced that the replacement isn't failing in one of them.

 

If you have a '92, BEWARE OF THE BRAKE SWITCH.  The '93 has a different design.

 

http://www.w-body.com/topic/32492-hard-brake-pedal-no-stopping-power/

[dogginred90]

I did some digging this morning. My vacuum line coming off the brake booster to intake has been rigged by previous owner. The rubber on one side is so soft I think it was collapsing under pressure. Going to dig and see if I have any hose just to see if it fixes it.

[dogginred90]

Ok well the Z34 now has the typical W body brakes again. The hose was collapsing cause with a new piece the brakes work good. Anyone know the part number for the booster vacuum hose? Thanks guys

[Heartbeat1991]

Just grab one from a junkyard.

[dogginred90]

I could do that. Around here these cars are getting scarce. I think there is one JY that may have what I need

[Schurkey]

 

My local Chevy dealer actually had one IN STOCK!!! The price wasn't horrible--$11.26; part number 10400822. They've sold 5 in the last year, so it must fit the 3.1, too.

From the link I already posted.  Note that the price was from the end of 2007.  Sure to be higher now, maybe discontinued.