Wilwood Dynalite Brake Upgrade

[kangaboy]

Still bleeding. I have pressure bled, pump bled, and gravity bled. It gets a little better each time, and I actually took it for a test drive Saturday to verify. Still no where near where they should be, as I can put the petal to the floor when trying to make a hard stop. One thing that I will do before bleeding again is keep the E-brake off. That issue popped into my head this morning.
Another thing I noticed on my test drive is that the drilled rotors are pretty damn loud. Are they supposed create a noticeable hum as you are driving along? I am hoping it is just a break in noise until the pads settle in. It's not a squeaking, but just a dull hum, and when I mash on the pedal, it's very noticeable.
Lastly, how tight are the pads supposed to be on the rotors? My front right rotor is pretty hard to move by hand after pumping the brakes and releasing. I figured there was supposed to be a little bit of a drag, as there are no springs to return the pads like in drums, but this seems like there is still a little bit of pressure in the system holding down the pads to the rotor.

Edit: How stiff should the pedal be when brakes are applied? Will it be the same as my drums, or will there be a different feel with the discs? (My drum brakes were set up with a pretty solid pedal)

[Piledriver]

The square seals in the calipers flex under pressure, and should actually pull back the pistons a few thousandths when pressure is released, more or less eliminating heavy drag, the wheel should spin freely.

You need to make sure the pads move in the slides right, a little brake grease helps, and sometimes a few strokes with a file or sandpaper on the caliper contact points of the pad is helpful.

Depending on caliper piston sizes, you may need a larger master.
What sizes are they?

[kangaboy]

Ehh, it's some variation of the Dynalite here...http://www.wilwood.com/Calipers/Caliper ... Dynalite-M
I didn't get the numbers off them before I mounted them, but the picture in the link matches them.
So I got home from work and bled the piss out of them. I put a couple bottles of brake fluid through with a pressure bleeder on all four corners and got no additional air bubbles. The fluid in all my lines is brand new, so if there is an air bubble somewhere, it is a very stubborn one that wont move. The brakes feel good. Squishy, but good. Squishy in that there is progressive stopping the more I push the pedal in. Once I press the pedal past the freeplay in the master, and actually start moving the fluid, I feel the bug slowing immediately. The farther I push it, the harder it stops. I haven't jammed the pedal to the floor while driving yet, but the bug stops way before I have gotten to that point. I just can't tell if that is the way they are supposed to be...I would vote that they are not...but it stops really well. So instead of the ~2-3 inches I used to push the pedal with the drums, I'm now pushing it ~1-6 inches with the discs. I wonder if as you mentioned, the master is too small to move the required amount of fluid around.

[Piledriver]

If they are actually Dynalite-Ms, there is only one piston size, which is 1.75", perfect if you have a 72 Monte Carlo, or something else with a huge master and power brakes, and 2000 lb on the front tires.
You are likely going to need a larger master...
What rear calipers were provided?

Wilwood laser engraves the part# on their calipers...

I'm running 1,25"x4 piston Forged internal Superlites on 298mm vented rotors in the front, and just upsized the rears to 944T/928 fronts (2x30 and 2x28), just barely maybe making it worth installing a proportioning valve, as the car has ~53/47 weight distribution at max braking if my CG info is right.
on a bug with a higher CG the 28mmx4 rears would probably be about right.

It stops like catching the cable on a carrier landing if I mean it.
If I lowered it more, it would probably be perfect.
The 2 psi residual pressure valves helped the pedal, but I now have some pedal travel with the larger rears.
Before it was ~like stock. (with 944T/928 rears with 28mmx4 pistons)

I switched back to front/rear split instead of dual diagonal so I could install the proportioning valve I picked up if needed, and as Ray said something that bugged me, about the possibility the stock 19mm T3 F/R circuits had any delay funny business going on.

IMHO 1.75"x4 pistons is ~ridiculous on a T1, but can b made to work. Getting a rear setup that actually provides decent bias with those may be interesting, maybe that's why FJCamper (still?) has a proportioning valve on the front brakes of one of his cars...

If they are regular forged Dynalites, they can be had in 1 3/8" which is ~reasonable.

See: http://brakepower.com/

[kangaboy]

If they are regular forged Dynalites, they can be had in 1 3/8" which is ~reasonable.

After checking again, they are the Dynalites. Didn't get a part number yet, but after comparing the stock photo to a photo I took, they are definitely the regular forged Dynalites.

What rear calipers were provided?

I only purchased the front kit. I was contemplating putting the late model front wheel cylinders on the rear, but after the issue that has come up, with maybe not moving enough fluid, I kinda wanted to hold off on it until I solved the current situation.

It stops like catching the cable on a carrier landing if I mean it.
...
...
Before it was ~like stock. (with 944T/928 rears with 28mmx4 pistons)

This is how I feel now. There is much more pedal travel, and it feels like the brakes get progressively better throughout the travel, but if I put my foot down, we stop...fast.

[66brm]

Have you checked the master? That's where I found the issue to be, once bled up the pedal was like the drums, but as you say the harder you push the more it feels like your face wants to kiss the windshield

[kangaboy]

Have you checked the master?

I haven't, but I don't know what I would be checking for. If it was a bad master, I would assume leaking from one of its orifices. I haven't had a bad dual circuit master before, so you can hit me with some knowledge as far as that's concerned.

[H2OSB]

I installed F&R discs in my son's super beetle. When bleeding, we pumped and bleed with a vacuum bleeder and could never get pedal resistance. I checked the boot on the MC where plunger enters from the bulkhead and found a leak. I bought a replacement MC and installed it. Problem solved.

H2OSB

[66brm]

Ok you need to bleed the master by cracking the brake light switches, or the lines at the master cylinder, often there will be a bubble trapped in there which will give the spongy feel. Have you also bled both nipples on the calipers, not sure precisely which model you have but some have multiple nipples and different hose entry points, always hook up to the lowest if practical

[kangaboy]

Ok you need to bleed the master by cracking the brake light switches, or the lines at the master cylinder, often there will be a bubble trapped in there which will give the spongy feel. Have you also bled both nipples on the calipers, not sure precisely which model you have but some have multiple nipples and different hose entry points, always hook up to the lowest if practical

Sounds like a plan, I'll bleed at the brake light switches as you suggested. As far as the caliper nipples, there are four on each caliper. Two on top and two on bottom (one for each corner). I have just been bleeding the top two of each caliper, seeing as that is where the air would be going. I even went as far as removing the lower caliper mounting bolt from the spindle mount so that I could swing the caliper out and have it pointing straight up. Hoping there is some air in the master.
Side note: When I apply the pedal to stop at a stop sign for example, the left caliper seems to grab more (bug pulls to the left). When I release the pedal and leave from a stop, the right caliper seems to drag a bit more (just an audible sound). Both front flex lines were just switched out, so I'm kind of at a loss on this one. Makes me wonder if there is an underlying issue with the master that I cannot see.

[kangaboy]

The heat wave has finally passed, and it's time to get back in the garage. I haven't driven the beetle for about a month now, due to the heat, and the fact that my GTI blows nice cold AC. I still haven't figured out my brake issue. I pressure bled both lines, both switches, and the additional port on top of my master cylinder, and no difference in pedal feel. Should I bleed the ports on the master the with the buddy method instead (have someone pump up the brakes and hold them while I release the pressure at the ports)? Or does that even matter? I have ran so much brake fluid through my lines, I am starting to think there is some mechanical issue somewhere. I have never had this much issue with bleeding, and like I mentioned earlier, the pedal was rock solid when I had the drums on it. I'm lost fellas

Edit: I thought the brakes were actually doing ok initially, until I ran the beetle in a little slalom race and slammed on the brakes at the end. The front left wheel locked up. Same thing when I was driving in the rain and realized I was gonna miss a turn. Tried to slow down to make the turn and front left wheel locked up again. Im pretty sure it's doing 90% of the braking. This is the reason I put it back on the jack stands. I need to figure this crap out before I start driving it daily again.

[Piledriver]

Did you ever get the part# off the calipers?

[kangaboy]

Got a part number... MDD 120-6815

http://www.wilwood.com/Calipers/Caliper ... o=120-6815

Appears they are the 1.75" pistons that you said enough about to make me skeptical about any future of having a stiff pedal
Thought I was playing it safe by getting a ready made kit. More research next time.

[66brm]

Try pushing the caliper pistons back in with the upper most nipples cracked then pump them up, they may need a cycle through to dislodge a stray bubble somewhere, it'll be something simple

[Piledriver]

You can have a stiff pedal with those, but the bias is all hosed up, those are ludicrous sized.

You'll need a larger master cylinder and rear calipers ~ 80-90% the front piston area, closer to same size if you want to use a rear bias adjuster.

Late Mustang rear caliper has a 45mm piston (floater, so double that) looks like a compatible handbrake setup.
Really wants a 1/2" rotor tho.(GTs want a 24mm rotor)

Front engined cars have huge fronts and tiny rear brakes.

There isn't much larger with a parking brake maybe some Subarus have parking brakes on the front calipers, might be worth some Googling.