Brake trouble

[stems]

Car #690 passed CT inspection over the weekend, despite having basically no brakes… I’ve bleed the system twice so far (in the correct order), and still I can put the pedal to the floor and get “some” braking. In no way would I feel safe driving this car on the streets in its current condition. So before I bleed them again, is there anything else I should look at or try? I have the ERA rear and the big brakes up front. Thanks.

[strictlypersonl]

First, remove the cover from the master cylinder area.

Check that both master cylinder pistons are returning completely.

Then make sure that the balance bar angle looks like the illustration in the manual.

Are both the front calipers shimmed square to the rotor?

Have you tried pressure bleeding? We never use the technique, but it might help drive out a stubborn bubble.

[trularin]

Could be air.

Look at the calipers and see if the bleeders are tilted or offset. Corny as this sounds, you have have a small bubble in the top of the caliper that is causing this.

Hey, it's just a thought.

[Lloyd GT40]

Make sure the calibers are mounted in the correct orientation. The bleed screw should be at the highest point

lg

[slithering]

stems,

It took me five times to bleed mine. What fluid are you using?

Chris

[david dickinson]

the seals in your master cylinder could be faulty , also silicone brake fluid is good for cobras as it is resistant to overheating and absorbes no moisture preventing corrosion on calliper pistons and can stay in the system indefinately.i have had it in my cobra for 6 years and the brakes are excellent and have been trouble free.another great feature of this fluid is it will not harm paintwork.

[strictlypersonl]

Wilwood and Sierra recommend against silicone (DOT 5) fluid. Use DOT 3 or 4. We use Castrol LMA or ATE Blue brands.

[stems]

Thanks for the suggestions guys.

Bob, I don't remember having to shim the calipers, I'm pretty sure the calipers came from you guys already installed on the adapter bracket, so all we had to do was bolt the bracket onto the steering knuckle.

I'll take a look at the master cylinder the next chance I get. With the holidays around the corner, I'm not sure when that will be.

I'm using a valvoline (i think) synthetic DOT 3 or 4, it comes in a grey bottle.

I have not tried a pressure bleeder, if I can't find anything wrong with the master cylinder, and bleeding it again doesn't help, I'll go that route.

Do you guys have any sage advice on bleeding? pump them up before cracking the bleeder, don't, etc.

-stems

[strictlypersonl]

Stems,

Does the pedal come up any if you quickly pump the pedal?

[stems]

The pedal keeps its full range of travel, just with little resistance for 75% of its travel.

[Hans-Olof Blom]

There are 2 bleeders on each caliper. At first I missed the inner one and experienced the same symptoms as you.

It also helps if you lift up the front of the car so the bleeders will be at the highest point.

[Tommy B]

Amazing...how in the hell did you pass inspection in CT with all the crap they go through for composites.....without brakes!! Tell me the secret and I'll fix your brake problem!!

[Clois Harlan]

Here is something I tried before. If you are running dual mc eliminate the pressure on your back brakes (either adjust your proportioning valve or re-position the bias bar on your brake pedal) so you are only applying pressure to the front brakes. Bleed only your front brakes until you get the pedal you want. Repeat the process for the rears and then adjust your bias bar on the brake pedals until you have the feel you want. This process worked for me but I was also using a pressure bleeder and some times a mini vac at the same time.

Clois

[stems]

HOB, I only noticed the one bleeder, I'll take a closer look at the caliper when I get home tonight. Thanks for the tip.

Tommy B, I chalk it up to my charming personality . I did have to go twice, the first time they failed me on a tail light problem (had two wires reversed), and a loose wheel bearing, which was also a simple fix. I went back the next morning (saturday) and was done within an hour. I'm not sure why everyone has problems, the guys I dealt with were pretty cool, maybe I just got lucky. On the brake test, I got a "Good enough for government work" comment making a reference to the fact that I work at Electric Boat. I also made a disparaging remark about "fart can" exhausts and honda civics when we were chatting before they started the inspection, I think that won me some brownie points.

[strictlypersonl]

I hope Hans-Olof has found the key to this. I already added his hint to the latest assembly manual iterations.

[stems]

Yup, I totally missed the other bleeder on the inside portion of the caliper, that would explain the poor braking performance I'll re-bleed the brakes next week sometime. If this doesn't solve my problem, I'll report back.

Thanks for all the help.