Wilwood/Strange 4 Piston Calipers soft feeling pedal

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straightlinespeed

straightlinespeed

Sometimes I pretend to be normal
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So I spent the day on Saturday working on the brakes for my brothers drag car. He installed all brand new Wilwood up front and Strange in the rear, 4 piston calipers with 4 bleeds on them. Also a new Wilwood M/C, which was recommended by Wilwood for a 4 disc set up.

We bench bled the M/C, then the brake system. No air what so ever coming out of the lines. Took the car for a drive down the road the car stops fine and it will lock the brakes if we push hard enough. With the pedal about half way down. He also tested the 2-step and it held the car @ 3500 rpm. However what throws us for a loop is we are both able to push the pedal right to the floor. It never gets that solid feeling. He called a race buddy that has the same set up and his car is the same way..

I guess Im just looking for opinions from people with a similar set up, to find out if your brake pedal feels or acts the same.
 
What is the bore of the master cylinder? Maybe to small? I use a Motive pressure bleeder and I don't even bench bleed the M/C. I just did mine on my68 Barracuda with the Wilwood M/C, Wilwood four piston fronts. and 11" Drum rear brakes. Pedal is high and firm.
 
Im positive it was a 15/16" bore for manual brakes. The pedal does return fully. I was thinking perhaps the pushrod was not adjusted right, but there is no slop in it..
 
straightlinespeed said:
Im positive it was a 15/16" bore for manual brakes. The pedal does return fully. I was thinking perhaps the pushrod was not adjusted right, but there is no slop in it..
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You know I am for ever working on my cars by myself, so I have to adapt to whatever comes up. This is why I use the Motive pressure bleeder. When your pumping the brake peddle to bleed the brakes, the fluid stays agitated. With the Pressure bleeder tank, you avoid this happening. Maybe you still have air in the system?
 
I would say you need the 1 1/32" master cylinder. Unless you have the same problem I had then it will take 1 1/8" master. I beat myself up for a long time with mine until I went with the 1 1/8" master now its high and solid.
 
Purple Haze said:
I would say you need the 1 1/32" master cylinder. Unless you have the same problem I had then it will take 1 1/8" master. I beat myself up for a long time with mine until I went with the 1 1/8" master now its high and solid.
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I was thinking the same thing. Years ago I had the opposite problem with a 89 Mustang race car I was helping my neighbor with. The brake pedal was hard as a rock! It was then I found out about using a Master Cylinder with to large of a bore. We installed a 15/16 bore on his and BAM! normal feeling pedal. That is why I suggested above that the OP may have the opposite problem.
 
I dont know what the trouble is, but I tell you what, if my brake pedal went to the floor with all those Cadillac parts, I would be one mad muh huckey.
 
Try rapidly pumping the pedal rapidly, 3-4 times hard, and then immediately push again and hold and see if then the pedal goes hard before reaching the floor. If this happens, it is a sure sign of air in the system.

The other area of softness is in the rubber lines. If they are old and cracked inside, they will tend to expand with pressure. Go to stainless braided covered teflon hoses; the will make firm brakes rock hard, and give great pedal modulation.
 
BTW, look at the position of the MC piston exposed at the pushrod and see if it is still recessed in the bore just a bit, with the pedal full up.
 
nm9stheham said:
Try rapidly pumping the pedal rapidly, 3-4 times hard, and then immediately push again and hold and see if then the pedal goes hard before reaching the floor. If this happens, it is a sure sign of air in the system.

The other area of softness is in the rubber lines. If they are old and cracked inside, they will tend to expand with pressure. Go to stainless braided covered teflon hoses; the will make firm brakes rock hard, and give great pedal modulation.
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Sorry, been busy and I have not been able to call my brother for the part# of the MC he got.

I did try the pump up method. It was consistent, same pressure in the pedal and could push it to the floor. It never had that hard, then soft feeling.

No rubber lines, on the car, any of the flexible are braided stainless

nm9stheham said:
BTW, look at the position of the MC piston exposed at the pushrod and see if it is still recessed in the bore just a bit, with the pedal full up.
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Im still curious about this, and it was the one thing we did not check into. I mentioned it but we never got to it. I'll try calling him today and get back to you guys.
 
Buschi340 said:
you're my neighbor next week :) I am in hagerstown friday and working in Shady Grove for 2 weeks.
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Was this post for me? If so, I am in Waynesboro VA, not Waynesboro PA. So I am 170 miles away. LOL But my wife is from Waynesboro PA......

But If I was in the area, I'd be very happy to meet you. I sell a lot of products from Germany and am German by descent. But I will be traveling for business for the next 2-3 weeks so it probably won't be possible.

Are you visiting at the Grove crane factory?
 
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yes, the post was for you. ooops mixed up VA with PA. Has every state a waynesboro? :)

Well, yes, I am working for Grove and the Shady Grove product lines... I am there for a 2 weeks Training.
 
OK, well very good! I hope your training and visit go well. See if you can schedule your next visit to Grove so that you can go to the big Mopar show at Carlisle PA that is held every year.
 
that would be too good. Unfortunately i have to follow the Training schedules. Well better the wrong time rather than never ;) Luggage already full of stuff :)
 
Update: My brother has a good pedal now, just the way it should be, high and firm.

After I left, he tried a few more things. Finally getting fed up he called Wilwood back to talk to them. The MC that they recommended was not big enough. He had to go to the 1-1/8" bore like Purple Haze had to. Of course they wouldnt cut him a break even though they are the ones that messed up sizing it.
 
Well the good thing is they are fixed. Plus like in my neighbors case (Wilwood advised them too) we had to go to a 15/16 to soften the pedal on his fox body. So someone will need one and buy it from you
 
SGBARRACUDA said:
Well the good thing is they are fixed. Plus like in my neighbors case (Wilwood advised them too) we had to go to a 15/16 to soften the pedal on his fox body. So someone will need one and buy it from you
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Yes, Im sure he will be able to sell it off, more than likely to some other racer at the track. Wait Im running a 15/16" bore... LOL
 
So the volume needed for the 4 calipers just ran it out of stroke.... yeah, Wilwood should know that! Now I wonder how far the MC pistons are coming back in the bore when the pedal is released.

Good to know the results; thanks!
 
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