Chocolate for brakes. The Dreaded Pudding Foot.

[Dudeland]

Ok, so like many, I am having problems getting a firm brake pedal, I think. 

 

I am a big guy, and I can create a lot of brake pressure, so with a bit of effort, I can almost stick it to the floor. 

 

Two things before we get into the weeds. 

 

1) How much free play should there be before you "Feel" the Brake touch the MC?  See the video below. 

 

2) When I get to the bottom of the stroke, I think it feels firm.  See the second Video

 

 New Tii M/C, Rear MKII disks, front standard 02 brakes, and SS Flex lines. I drilled out the residual pressure valve used for drum brakes. 

 

Buddy bled,  power lead at 5psi, 15psi and 30 psi (got some seepage around the grommet at 30Lbs). 

 

The brakes were always soft and would never lock up on dry pavement, so I replaced the M/C, but it still feels soft. 

 

I have a new performance brake booster pivot (yet to be installed) and a pedal box rebuild kit ( yet to be installed).   Is it a linkage issue that is causing it to be squishy?  I suspect that I can take some of the slack out, but dammit, I need to be able to lock up the tires.

 

Do I need to bench bleed?  (The wires are remnants of the relay wiring from removing the A/C stuff. For sale shortly) 

 

 

Stare at my crocks. That's a paddling.

 

 

 

 

Pedal slack travel. 

 

 

 

Full to the floor. 

 

 

 

 

[Dudeland]

I do have a big brake kit, but that is not going to fix the soft pedal right? 

[uai]

17 minutes ago, Dudeland said:

The brakes were always soft and would never lock up on dry pavement, so I replaced the M/C, but it still feels soft. 

Let's start there.
I'd get proper pads and and bed them according to manufacturers instructions.
Being soft and lack of feel is one thing but not being able to lock the wheels is not something I'd drive around with.
With a ti(i) MC 23,81mm and standard (does this mean non ti(i)?) front you should definetely have a firm pedal.
I've had multiple MC (NOS) that were junk out of the box or failed in a short time after being put into the car because of too long storage with the rubbers being porous and the cylinder walls having little marks of corrosion. 
So I will not anymore install a MC of unknown age abfore having it apart.

Have somebody look into the reservoir while applying the brake - only during the first mm of stoke there may be something visible of fluid coming back into the reservoir.

 

Edited August 5 by uai

[uai]

1 minute ago, Dudeland said:

I do have a big brake kit, but that is not going to fix the soft pedal right? 

might be if the calipers are the Problem

Edited August 5 by uai

[popovm]

The pedal box rebuild kit helped remove slop and for my brakes to start engaging earlier in the pedal stroke. 
 

Being able to easily(ish) go all the way to the floor like that doesn’t seem right. Does the pedal get more firm right after bleeding and eventually get soft again or is it always soft like that?

[Dudeland]

1 minute ago, uai said:

Let's start there.
I'd get proper pads and and bed them according to manufacturers instructions.
Being soft and lack of feel is one thing but not being able to lock the wheels is not something I'd drive around with.
With a ti(i) MC 23,81mm and standard (does this mean non ti(i)?) front you should definetely have a firm pedal.
I've had multiple MC (NOS) that were junk out of the box or failed in a short time after being put into the car because of too long storage with the rubbers being porous and the cylinder walls having little marks of corrosion. 
So I will not anymore install a MC of unknown age abfore having it apart.

Have somebody look into the reservoir while applying the brake - only during the first mm of stoke there may be something visible of fliud coming back into the reservoir.

Yes, I see a bit of a pop on the reservoir. 

 

M/C is a new one from Ireland.  (1MM smaller diameter reproduction) 

 

Yellowstuff Pads were installed on all four corners to help with trying to get lit to lock up.  The last thing to sort out is the brakes, tsp they aren't bedded yet. 

 

Can I adjust the slack out? I haven't gotten to that by searching the FAQs yet. 

[Dudeland]

4 minutes ago, popovm said:

The pedal box rebuild kit helped remove slop and for my brakes to start engaging earlier in the pedal stroke. 
 

Being able to easily(ish) go all the way to the floor like that doesn’t seem right. Does the pedal get more firm right after bleeding and eventually get soft again or is it always soft like that?

Did yours have as much slack as mine before the rebuild? 

 

No, they are always soft, before and after the mc.  

 

[Dudeland]

8 minutes ago, uai said:

might be if the calipers are the Problem

The calipers aren't hanging up.  They move freely, but I will double-check. 

 

[uai]

If the brakes aren't bedded - do that first 10x braking medium pressure 60-35 miles with cooling in between

then 10 x braking 100-50 miles with medium high pressure long cooling phases in between
Then try some hard braking.
When everything is brand new it needs to settle a bit. But I suspect the MC being toast

Edited August 5 by uai

[Dudeland]

Just now, uai said:

If the brakes aren't bedded - do that first 10x braking medium pressure 60-35 miles with cooling in between

then 10 x braking 100-50 miles with medium high pressure long cooling phases in between
Then try some hard braking

Yes, EBC has a braking procedure and a special coating on the pads that beds in the brakes.

But I don't think it is causing the squishiness. 

 

[popovm]

6 minutes ago, Dudeland said:

Did yours have as much slack as mine before the rebuild? 

 

No, they are always soft, before and after the mc.  

 

It was significant. You might have more slack but mine was pretty bad. If you pull the carpet and insulation pad, stick your head down, and work the pedal with your hand and  you’ll be able to see how much of the slop you have is from the worn pedal box components. All the pivots, etc will be jangling around. I’ll bet a dollar that slop is because of the worn pedal box. It’s impressive how much tighter they get when rebuilt. 

Edited August 5 by popovm

[Dudeland]

1 minute ago, popovm said:

It was significant. You might have more slack but it was pretty bad. If you pull the carpet and insulation pad, stick your head down, and work the pedal with your hand and  you’ll be able to see how much of the slop you have is from the worn pedal box components. All the pivots, etc will be jangling around. I’ll bet a dollar that slop is because of the worn pedal box. It’s impressive how much tighter they get when rebuilt. 

I was hoping to avoid doing the pedal box. I knew I should have done it when I had the floor out.  There is no easy way of doing it.

 

Dang, 

 

[Preyupy]

Just because no one has asked yet, and I have seen this way too many times over the years.  

You do have the calipers on the correct sides?  The bleed screws should be aimed UP.  

You would not be the 1st one.  

 

[popovm]

1 hour ago, Dudeland said:

I was hoping to avoid doing the pedal box. I knew I should have done it when I had the floor out.  There is no easy way of doing it.

 

Dang, 

 

Well, to be clear, the softness throughout the stroke is a different problem. You can safely drive around the slop but the squishiness (aka “puddin foot”, I like that btw) is a safety issue. I’d fix that first. Adding in the pedal box is unnecessary scope creep at the moment. It’s still worth it in the long run but it’ll be more straightforward to focus on one thing at a time: the chocolate puddin you’re squishin with those crocs. 

Edited August 5 by popovm

[Son of Marty]

1 hour ago, Preyupy said:

You would not be the 1st one.  

 

You'd not be in the first thousand to do it, I think, IMO too much slack in the system due to wear and miss adjustment of the linkage. There is no advantage to boosting you bleeder pressure above 5 to 7 psi micro bubbles can be infused into brake fluid above that,