Cascade Crew

QwkTrip · Posted: Wed Jun 01, 2016 4:40 pm Post subject:

Oh, and the torque arm already smacked the road today. It was just a little lump in the pavement, I couldn't believe it.

aaron_sK · Posted: Wed Jun 01, 2016 10:05 pm Post subject:

Welcome to your new life.

QwkTrip · Posted: Tue Jun 07, 2016 9:23 pm Post subject:

Trying to improve my brakes. Got the LS1 F-body brake master cylinder installed tonight. And I have Russell speed bleeders to help me bleed the brakes once and for all. But I need to fix a very slow leak at the rear calipers where the hose connects. I think maybe the banjo bolt and crush washers are wrong style so I'm trying to figure out what to use.

chevymad · Posted: Tue Jun 07, 2016 10:18 pm Post subject:

I doubt it's the banjo bolt. However, I've run into some crush washers that are probably chinese and made of too hard of material. Almost impossible to get to seal no matter how tight the bolt is. I'd just go and buy some new washers and give it another try. There were a few years there that I wouldn't even use the new washers that came with the caliper cause they always leaked. I'd just reuse the old ones. Lately they've been ok though.

QwkTrip · Posted: Wed Jun 08, 2016 2:38 pm Post subject:

Swapped master cylinder to LS1 style, bled the heck out of the lines, and the brakes feel exactly the same. Long pedal stroke and over assisted, then pedal goes hard and there is little feedback before front brakes lock up. I adjusted the prop valve until it was wide open and I still can't lock up the rear brakes. In fact, I didn't notice any difference with how the rear brakes felt after 4 full rotations of the prop valve.

The rear brakes lines are really difficult to bleed. I had to put 30 psi vacuum on it and just wait a while until fluid would flow. Then it bleeds fine. It was like that the first time I put the brakes together too. The prop valve is a used SSBC that I got from Paul years ago and I think it may be the culprit. Seems to lack adjustability and is blocking flow when bleeding brakes. I am going to change out the prop valve and see if that helps.

Dewey316 · Posted: Thu Jun 09, 2016 11:04 am Post subject:

Do you have the adjustable valve on fronts or rear?

QwkTrip · Posted: Thu Jun 09, 2016 2:49 pm Post subject:

On the rear.

Twilightoptics · Posted: Thu Jun 09, 2016 8:40 pm Post subject:

Don't know what all the fuss is about. My thirdgen master always felt great, if it was bled properly. Not locking up the rears is not uncommon. Something is definitely blocking flow for the rear if it takes that long under vacuum to bring fluid back. That said, it would actually make your pedal feel stiffer....

QwkTrip · Posted: Fri Jun 10, 2016 9:44 am Post subject:

Paul, did you use synthetic brake fluid?

Twilightoptics · Posted: Fri Jun 10, 2016 4:57 pm Post subject:

Just plain old parts store DOT3/4

Alphius · Posted: Fri Jun 10, 2016 6:24 pm Post subject:

Plain DOT3 here too. My brakes are very solid with plenty of feel. I did have to back off my prop valve to bleed the rears without taking an eternity.

QwkTrip · Posted: Sat Jun 11, 2016 12:13 am Post subject:

QwkTrip · Posted: Sun Jun 12, 2016 5:12 pm Post subject:

I did the whole shebang this time and the brakes feel nearly the same. Bench bled the master, new prop valve, bled it very well and I still can't lock up the rear brakes. I guess I will have to measure rear line pressure some time and see what I'm getting back there. Kind of done with it for now because it is interfering with me driving the car every done I bust open the brake lines.

Twilightoptics · Posted: Sun Jun 12, 2016 5:39 pm Post subject:

Which booster are you using? How does the pedal feel with the engine off?

Maybe too much assist from the booster causing the feel issue.

Again, not locking up the rear's is not uncommon.

QwkTrip · Posted: Sun Jun 12, 2016 8:54 pm Post subject:

Stock 3rd gen booster.

I am less concerned about how much it is being boosted and more concerned about the brake take-up rate, feedback when braking hard, and brake balance front to rear. The take-up rate sucks (long travel before responding), followed by very poor feel under hard braking, and very poor front-rear balance. Right now the brakes would perform terrible on an autocross or road course with a lot of front lock up if pushing the car hard.

QwkTrip · Posted: Sun Jun 12, 2016 9:23 pm Post subject:

This might be a clue as to what is happening. I might be too heavily front biased after upgrading to C6 brakes. Rear drag radials are a contributing factor too.

http://www.stoptech.com/technical-support/technical-white-papers/rear-brake-upgrades

Twilightoptics · Posted: Mon Jun 13, 2016 6:28 am Post subject:

Could be, but thats not really going to change pedal feel though. Feel is based on master bore, pedal geometry, booster and aeration. I had those C4HDs up front and used standard front C4 front brakes in the back, with all stock thirdgen disc master and booster. Pedal felt like a normal stock thirdgen.

QwkTrip · Posted: Mon Jun 13, 2016 7:44 pm Post subject:

I don't know what a stock thirdgen pedal feels like. Been too long to remember anything like that. All I know is my pedal feel sucks.

I will inspect the rear brake calipers and make sure everything moves freely. Probably should have done that earlier.

QwkTrip · Posted: Mon Jun 13, 2016 7:56 pm Post subject:

The bad thing is the car now has other problems. I accidentally left the IAT unplugged when filling the AC freon tonight. Didn't realize it for a while and then the car started running badly. It backfired through the intake manifold and stopped running and was flooded out horribly. Found the IAT connector undone and had to clear the flood by disconnecting fuel injectors and spraying starting fluid in the throttle body. Car would start but die again shortly after and had to keep repeating the flood clearing with starting fluid. I figured the tune had learned bad habits so I reloaded the original tune and car seemed to run okay. I went for a drive just to really clear things out and the car died again couple miles from home.... and wouldn't restart. Loaded the old tune again and baaaaaarely got the car running and revved the snot out of the car all the way home. Something isn't right now.

aaron_sK · Posted: Mon Jun 13, 2016 9:25 pm Post subject:

Vacuum leak from backfire?

Clear flood by cranking at WOT with fuel cut off. IME spraying ether tends to just make everything worse unless you're working on a diesel or a lawnmower.