Important Brake Question(kinda long)

[WilwoodFiveO]

Hey everyone,

About 4 months I bought the Wilwood Dynalite Series 4 piston system for both the front and the rear of my 93 GT. When I bought the kits Wilwood told I did not need to upgrade my booster. So I just finished lengthening my pushrod, seeing how there are discs in the rear now and finished bleedding the entire system (16 pistons) PIA, took a real long time. The problem is the pedal still seems quite soft for the system to be fully bleed. When I bleed the calipers I didn't stop until each of the bleed screws shot out a complete stream of fluid. I have no idea what the problem might be or if its just me being to concered. Any ideas?

One thing that you all might think about is that I ran all new hardlines too, so is the fact that its basically a brand new brake system have anything to do with it.

Any tips or helpful comments would be greatly appreciated, hope you all can help.

Tyler

 

[bimmertech]

just covering the basics here, but are all the bleeders pointing up? do you have an upgraded m/c?

 

[WilwoodFiveO]

yes, there are actually 4 bleeder valves on each caliper, one for each piston and i bleed each one. I think that is correct. And also yes, I upgraded to a Wilwood Master cylinder and porpotioning valve. Tell me what you think?

 

[bimmertech]

i would say that you still have air in the system, most likely the m/c. did you bench bleed the hell out of the m/c? if not it will take a considerable amount of bleeding.

also has the stock proportioning valve been deleted?

i have never messed with wilwood calipers before, but most 4 piston calipers will only have 2 bleeders per caliper--1 on each side. i am very interested as to how they postition the bleeders.

 

[WilwoodFiveO]

yes, I did indeed bench bleed the master cylinder before hand and made sure of it.
I also deleted the stock porpotioning valve and replace it with the Wilwood one. I have the front lines running out of the primary output of the master cylinder( using a T block, one main line out that that splits into front right and front left) and then I have the rear line comming out of the master cylinder and hitting the porpotioning valve and then continuing back to where it meets the factory hard line right near the firewall.

The calipers are all the same all around and are all mount at the rear of the caliper (meaning towards the back basically perpindicular to the pavement) On each caliper there are 4 bleeder valves and in this case two on each caliper are indeed facing upward.

On the instructions it dosent clearly state any certain two bleeder valves and they all infact look excactly the same.

Now that I think of it though, I probably should bleed the bottom screws first and then bleed the top ones last, going from caliper to caliper. Do you think this makes sense. I will try to do that tomorrow and see if that effects anything.

Is there anything else you can tell me from all the explaining I have just done. I thank you for ur help.

Tyler

 

[bimmertech]

Now that I think of it though, I probably should bleed the bottom screws first and then bleed the top ones last, going from caliper to caliper. Do you think this makes sense. I will try to do that tomorrow and see if that effects anything.


Tyler

i see, they run a generic caliper that can be used on any side. you should not have to bleed all 4 bleeders. you should only have to bleed the 2 bleeders that are on the top of each caliper. bleeding the lower bleeders after the uppers will most likely introduce the air into your system. try that and keep us posted.

 

[jrichker]

Here's a helpful device...

Garden Sprayer Pressure Bake Bleeder

1 each pump type garden sprayer, 1 - 1 ½ gallon capacity (size doesn’t matter much, it just has to be cheap and small enough to be easy to work with)
6-10 feet 3/8” clear plastic tubing
1 each ¼” brass pipe tee
1 each ¼” pipe to 3/8: hose adapter
1 each pressure gauge 0-60 PSI or so – all you’ll ever need is 5- 10 PSI, so the gauge range doesn’t have to be high.
1 each large rubber stopper – this is the hard part to find. It may take some searching to find one that is a snug push fit to the inside of the filler port on the master cylinder. You can use silicone rubber to seal a brass fitting to an old master cylinder cap, but they tend to leak too much.
Home Depot or Lowes has some ¼” brass pipe stock that is continuously threaded in the electric lamp repair department, along with the brass nuts that go with it. This is better than a pipe nipple, since the nuts can be used to secure the pipe in the cap or stopper.
OR if you can’t find the threaded pipe stock,
1 each ¼” nipple, 1 ½”- 2” long

The rubber stopper needs a hole drilled in it for the ¼” pipe nipple or threaded pipe stock. After you drill the hole, use some silicone gasket sealer to seal the pipe nipple as you push it into the rubber stopper. If you used the threaded pipe stock, use the nuts to secure the stock into the stopper.

If you can’t find a suitable rubber stopper, an old master cylinder cap can be used. Drill a ½” hole in the center for the pipe fitting. Cut the brass pipe stock to about 1”- 1 ½” long, the exact length isn’t too important. Push it through the hole in the master cylinder cap and thread one nut on top of the pipe stock where it sticks though the cap. Put another nut on the other side of the cap to lock the pipe stock in place. Apply some silicone rubber gasket sealer to both sides and when it is dry, screw the ¼” pipe that sticks out of the top of the cap into the tee.

Remove the sprayer hose and wand from the garden sprayer. You may find it easier just to cut the sprayer hose off short and connect it to the 3/8” plastic tubing. The idea is that the 3/8” tubing connects to the pickup tube inside the sprayer in a reliable, leak proof fashion. Another alternative is to remove the spray nozzle from the end of the spray wand and connect the 3/8” tubing to the wand. This leaves the hand valve in place and may be useful to start/stop the flow of brake fluid.

The 3/8” plastic tubing connects to the pipe tee using a push on hose barb type adapter. The pipe tee has one port for the gauge, one for the 3/8” hose and the other to connect to the rubber stopper or master cylinder cap that you modified.

Fill the pump sprayer with a quart of brake fluid. Set the garden sprayer on the ground and screw the pump handle down tight, and pump until brake fluid fills the plastic tubing. Then put the modified stopper or master cylinder cap on the master cylinder and pump slowly to make sure that nothing leaks or pops loose. No leaks, continue pumping until you get 5-10 PSI. Put a 6”-12” length of clear plastic tubing on the bleeder ports. Then open the bleeder ports on the wheel cylinders one at a time and bleed until the bubbles are gone. I use a 2 liter soda bottle with a coat hanger to catch the fluid . DO NOT REUSE THE OLD BRAKE FLUID. Repeat the process until you have finished all 4 wheels. You will have to pump the sprayer several times to maintain the 5-10 PSI needed to do the job. When finished bleeding, loosen the pump handle to relieve the pressure, remove the stopper/modified master cylinder cap and test the pedal.

 

[WilwoodFiveO]

i see, they run a generic caliper that can be used on any side. you should not have to bleed all 4 bleeders. you should only have to bleed the 2 bleeders that are on the top of each caliper. bleeding the lower bleeders after the uppers will most likely introduce the air into your system. try that and keep us posted.

Ok I went around and bled all the calipers using only the two correct bleed screws on each caliper. The pedal got a good amount firmer but is still very spongy at the beginning of travel.

My question is, after I bled them I topped the master cylinder off (this master cylinder, the cover is held on by four screws and I have to take the entire cover off to fill it) So my question is when I topped it off do you think I let more air into the system? Should I bleed them all again?

My next question is how come when I turn on the car the brake pedal gets softer? Is this normal? From this situation I have to ask this question. Should I top off the fluid when the car is on or does it not make any difference? PLEASE HELP. I know I'm so close. Thank you

Tyler

 

[bimmertech]

Ok I went around and bled all the calipers using only the two correct bleed screws on each caliper. The pedal got a good amount firmer but is still very spongy at the beginning of travel.

My question is, after I bled them I topped the master cylinder off (this master cylinder, the cover is held on by four screws and I have to take the entire cover off to fill it) So my question is when I topped it off do you think I let more air into the system? Should I bleed them all again?

My next question is how come when I turn on the car the brake pedal gets softer? Is this normal? From this situation I have to ask this question. Should I top off the fluid when the car is on or does it not make any difference? PLEASE HELP. I know I'm so close. Thank you

Tyler

i highly doubt that opening the m/c will introduce air into the system. when you turn on the car the pedal gets softer due to the brake booster having vacuum again.

have you driven the car yet? if you have does it seem to stop well without you having to stand on the pedal?

basically you have re-engineered the entire brake system and the pedal may not retain the same amount of travel as your previous setup.

having said these things, i am not there to evaluate pedal stiffness so that ball is in your court. if the car stops well and you feel comfortable driving it then i say it is in the bag. if you feel the brakes are not am improvement over your previous setup then i would contact wilwood for specifics on pedal travel and feel.

 

[WilwoodFiveO]

i highly doubt that opening the m/c will introduce air into the system. when you turn on the car the pedal gets softer due to the brake booster having vacuum again.

have you driven the car yet? if you have does it seem to stop well without you having to stand on the pedal?

basically you have re-engineered the entire brake system and the pedal may not retain the same amount of travel as your previous setup.

having said these things, i am not there to evaluate pedal stiffness so that ball is in your court. if the car stops well and you feel comfortable driving it then i say it is in the bag. if you feel the brakes are not am improvement over your previous setup then i would contact wilwood for specifics on pedal travel and feel.

Yes I have driven the car and I can tell you that the car stops very firmly. The problem is the calipers don't seem to fully clamp until a little way down the stroke of the pedal. But the pedal does not hit the floor when pushing down fully on the pedal. When fully compressed the pedal is about an inch and a half away from the floor. (which is about right) From this I know that the problem isn't air in the system.

So my question is, Is there a way to adjust the stroke of the pedal since this new brakes act different.
With this being said I have already extended my pushrod, and now I'm thinking I must have to extend it farther. That is the only thing I can think of that would be causing this problem. Agree, Disagree? Tell me what else you think. Thanks man, you've been a great help.

Tyler

 

[bimmertech]

So my question is, Is there a way to adjust the stroke of the pedal since this new brakes act different.
With this being said I have already extended my pushrod, and now I'm thinking I must have to extend it farther. That is the only thing I can think of that would be causing this problem. Agree, Disagree? Tell me what else you think. Thanks man, you've been a great help.

Tyler

you really can't go wrong with adjusting the pushrod to see if it changes anything. it may just be the way the kit is designed. have you tried messing with your adj proportioning valve to see if that makes a diff?

btw, i want to see pics of your setup. i like seeing big brakes more than i like seeing badass engines.

how thick are your rotors? what model caliper--dynalite? 2 piece/1piece rotors? slotted/drilled/plain?

 

[WilwoodFiveO]

you really can't go wrong with adjusting the pushrod to see if it changes anything. it may just be the way the kit is designed. have you tried messing with your adj proportioning valve to see if that makes a diff?

btw, i want to see pics of your setup. i like seeing big brakes more than i like seeing badass engines.

how thick are your rotors? what model caliper--dynalite? 2 piece/1piece rotors? slotted/drilled/plain?

Yeah tommorrow I'm going to get up early and start messing with that thing. Hopefully I can get the brakes a little bit firmer until I feel safe with them and then I'll take the car to an empty lot and adjust the prop. valve.

I'll get some pics to you as soon as possible for you.

Heres the link to the front kit I have:
Dynalite Pro Series Front Hub Kits
http://www.wilwood.com/BrakeKits/Pages/08/index.asp

Heres the link to the rear kit:
Dynalite Pro Series Rear Parking Brake Kits
http://www.wilwood.com/BrakeKits/Pages/12/index.asp

Its actually pretty weird to look at my front rotors are actually smaller than my rear rotors, but both kits utilize the same excact caliper all around.
The reason I just went with the basic 4 piston fronts was $$$ reason but I plan on running the Superlite 6 Big Brake Front Hub Kit but I have to wait till I get some more money in hand.

Heres the link to that kit I want:
http://www.wilwood.com/BrakeKits/Pages/02/index.asp

I can't wait to add the six pistons, but I still now that my car is going to stop amazingly well compared to stock seeing how I have 4 piston calipers all around. I can honestly tell the 6 piston kit will be for nothing but looks when I do get them installed.

Anyways, back to what I do have, I'm also running their Aluminum Tandem Chamber Master Cylinder http://www.wilwood.com/Products/006-MasterCylinders/009-ATCMC/index.asp along with their Kob Style Proportioning Valve http://www.wilwood.com/Products/006-MasterCylinders/001-PV/index.asp

Give me your thoughts. Thanks dude.

Tyler

 

[WilwoodFiveO]

ttt ANYONE else having any ideas of what could be causing the problem? Thanks, really need some ideas.

Tyler

 

[WilwoodFiveO]

Hello everyone, I'm back once again, but this time with the anwer!!!!

I finally got a hold of someone at Wilwood who had more than half a brain and who I could actually have an intelligent discussion with. I explained to him the problem and the feel of the pedal while driving and right away he knew the problem..

When I purchased my front and rear brake kits, Proportioning Valve and Master Cylinder from some booth at Fun Ford Weekend the guy sold me the wrong m/c. He sold me the m/c with the bore size of 1.00 instead of the one you need to use when using a booster which is the m/c with a bore size of 1.12. The problem was the 1.00 one was to be used on a manual brake system where there is no help aided to your foot by a booster.

The guy on the phone explained to me that since I had the help of the booster added onto the stroke of the pedal that the cylinder was to small for what I needed.

So I had two options, one was to completely take off my booster and mount my m/c right to the firewall or just by the larger master cylinder with the bore of 1.12. I then got a hold of the guy who I bought the Wilwood products from originally and he is sending me the correct one free of charge (and its worth $50 more).

Just thought I would let everyone know what the problem is and maybe let everyone learn this new little something about a brake system, because I sure did. Talk to you all later.

Tyler