Brakes: Won't Bleed Properly

[opus10583]

So....

Shop B had it back and managed to get it safe if not quite right: They say they adjusted the booster push-rod, which shop A had said they'd taken consideration of.

But, after ~20miles the car now felt like the handbrake was grabbing (shop A said something about having to adjust it...), so I adjusted the cable according to the online manual and drove it ~2miles, felt great, handbrake was way high though, so I adjusted it again and off I went.

~10miles later the brakes started to grab again, within a mile it felt like I was stepping in the pedal and I could smell toasted pad lining. Couldn't make it another 1/2 mile to a parking lot for all the bucking and burning.

Car was locked up solid: Would not budge when I pushed against the trunk with both legs planted on the ground.

When the flatbed arrived a half hour later I could drive it on with no problem, off as well, pedal now just as long and spongy as when I got it back from shop A.

It's now where it should have been all along; the very first shop I used, where the chassis was fixed and all the suspension bits replaced, that was too busy to do everything else I wanted and is still too busy to do anything else I need now... One of their charges took Best in Show at this year's Scarsdale Concours, a 1950 Abarth 205.

The stainless braided hoses I bought are crap: The center rear one was never right, absolutely incorrect t-block junction fitting and had to be replaced with a standard hose, the front hoses crimp on full lock, and after only ~200miles are already falling apart.

...When all is said and done, ~$700 so far and another $150 expected, I will name names.

Ciao,
Mark

PS: IAP will have a new set of ss braided hoses to the shop on Monday.

[124ADDHE]

Where did you get those first SS lines from? Tough luck!

[opus10583]

Where did you get those first SS lines from? Tough luck!

I want to name them, because I've bought about $2000 worth of parts from them in 4months and their attitude so far is slimy belligerent denial of any culpability, but I'm going to give them a chance to clear their name first.

Set of lines and shipping: $140
Installation: $100
T-block and shipping: $74
Fifth hose and shipping: $45
Second Shop: $175
IAP Hoses and shipping: $165

$699

[WYSpider]

Opus, nice quote: "Buy the ticket, take the tour". Here is how Hunter tackles poor customer service: https://www.youtube.com/watch?v=VrOhvSvKIhc

[opus10583]

Opus, nice quote: "Buy the ticket, take the tour". Here is how Hunter tackles poor customer service: https://www.youtube.com/watch?v=VrOhvSvKIhc

In the original it's "buy the ticket, take the ride", but tour is about as good as i could get it idiomatically.

...Still haven't gotten notification that the 2nd set of lines has shipped.

Ciao,
Mark

[ventura ace]

It sounds like the pushrod is still too long, and needs to be adjusted again to make it shorter. A push rod that is too long will cause both symptoms that you described:
1) Inability to bleed the air out
2) Brakes lock up after everything warms up

What's happening is that the MC internal spool valves are pushed too far forward, opening up an upstream flow path to dump the brake fluid when attempting to push the pedal, which prevents you from being able to chase the air out through the wheel calipers. It also can close off the downstream flow path that would normally allow the pressure to bleed off the calipers when you realease the brakes.

If you want to verify that this is the cause, it's really easy. Just back off the two 13mm nuts that hold the MC to the brake booster about 1 or 2 turns. This has the same effect as shortening the rod. Also, if your brakes ever lock up on you as you described, this is a quick easy way to releive the pressure, and doesn't make a mess (as would happen if you cracked open a brake line to relieve the pressure.

Alvon

[opus10583]

It sounds like the pushrod is still too long, and needs to be adjusted again to make it shorter. A push rod that is too long will cause both symptoms that you described:
1) Inability to bleed the air out
2) Brakes lock up after everything warms up

What's happening is that the MC internal spool valves are pushed too far forward, opening up an upstream flow path to dump the brake fluid when attempting to push the pedal, which prevents you from being able to chase the air out through the wheel calipers. It also can close off the downstream flow path that would normally allow the pressure to bleed off the calipers when you realease the brakes.

If you want to verify that this is the cause, it's really easy. Just back off the two 13mm nuts that hold the MC to the brake booster about 1 or 2 turns. This has the same effect as shortening the rod. Also, if your brakes ever lock up on you as you described, this is a quick easy way to releive the pressure, and doesn't make a mess (as would happen if you cracked open a brake line to relieve the pressure.

Alvon

Hi Alvon,

I'm confident the people who have it now are capable, but I now have a space in which I can work on it myself, and yours is the most reasonable advice I've heard hear yet.

Thanks,
Mark