Fishing for ideas about brake pedal going to floor

[Bill Pressler]

My '64 Daytona (drum, non-power brakes) has new brake lines, and wheel cylinders all around. When I got the car in March, it pulled drastically to the right but the pedal didn't go the floor like it does now. M/C is full of fluid. Any ideas?

Thanks,
Bill Pressler
Kent, OH
'63 Lark Daytona Skytop R1
'64 Daytona Hardtop

[Milaca]

Perhaps not all of the air was evacuated from the system when the lines were replaced. As for pulling to the right side, perhaps your left side brakes aren't self adjusting and may need some manual adjustment (turn the star wheel through the oval hole) or maybe just that side has air in the system? What I would do: pump the brakes until the pedal comes up, find a way to retain pressure on the pedal (prop a board against the pedal or get a helper to hold the pedal down) while you loosen the brake bleeder scews. If the fluid comes out in irratic spurts, then you have air in the system.


Brent's rootbeer racer.
MN iron ore...it does your body good.

[Studeman]

If the pedal goes to the floor- but you still stop...I would probably look at the shoe adjustments first. These can be somewhat tricky to set. Too tight, and the shoes get hot, expand, and start rubbing- causing a significant pull or violent vibration. Too loose, and you lack a solid pedal. It's the place I always start.
Then, I move to the adjustment ROD from the pedal to the Master cylinder...
Not knowing more... you may have had a trapped air-pocket in the new lines etc.. that finally worked it's way to a wheel cylinder- and now you have a soft, low pedal.

Reset the shoes (FIRST)... then re-bleed the brakes... If the pedal is still low... move to the push-rod adjustment.. and finally to the Master Cylinder itself.

Ray


Specializing in Studebaker Restoration

[Dick Steinkamp]

Did you fix the pull to the right? Did the brakes work fine and then the pedal to the floor problem, or did it happen AFTER some work was done to the brakes?

You didn't mention new M/C. This could be the problem. At the least you could bench bleed the M/C (this can be done while it is still in place) then bleed the brakes again. If all else is new and tight and not leaking maybe the M/C has failed.

BTW, pulling is generally not an adjustment problem. It was for mechanical braked cars like a Model A, but one of the beauties of hydraulics is that they apply force to the shoes evenly. If the adjustment is clear off on one wheel there MAY be a slight initial pull to the opposite side, but it will go away immediately as you continue to brake. Bad adjustment will give you a low pedal, however.

Dick Steinkamp
Bellingham, WA

[Bill Pressler]

The pulling has been cured with new wheel cylinders and hoses. But man, that pedal didn't go to the floor until after the new parts.

Bill Pressler
Kent, OH
'63 Lark Daytona Skytop R1
'64 Daytona Hardtop

[Dick Steinkamp]

quote:Originally posted by Bill Pressler

The pulling has been cured with new wheel cylinders and hoses. But man, that pedal didn't go to the floor until after the new parts.

Did you ever have pedal after the new parts or did it start going to the floor immediately after changing the parts?

If never a good pedal after changing parts, I've found that the firewall mounted M/C's almost always have to be bench bled to get the air out (not my experience with the underfloor mounted M/C's).

Dick Steinkamp
Bellingham, WA

[ROADRACELARK]

Bill,
Being your car is a 64, it should have a split M/C. Having installed new lines, WC's etc, that is requiring more pressure from the M/C and causing it to By-pass internally. That's why no loss of fluid.

Dan Miller
Atlanta, GA

[img=left]http://static.flickr.com/57/228744729_7aff5f0118_m.jpg[/img=left]
Road Racers turn left AND right.

[Flashback]

Did you bleed the brakes ?

Tex E. Grier

[Bill Pressler]

quote:Originally posted by Flashback

Did you bleed the brakes ?

Tex E. Grier

Yes, they've been bled a couple times.

Bill Pressler
Kent, OH
'63 Lark Daytona Skytop R1
'64 Daytona Hardtop

[Milaca]

If you pump the pedal 2 or 3 times, does the pedal get a better feel or does it still go to the floor?


Brent's rootbeer racer.
MN iron ore...it does your body good.

[ozarkman]

Check all the fittings from the wheel cylinders up to the master...you might have a small leak. It's best to check them while someone is standing on the pedal...but if you don't have any brake pressure it might not show. Do the brakes work at all? What bleeding procedure did you follow?

From deep in the Ozarks...

Fred

[52 Ragtop]

Be sure to check and adjust the M/C linkage per the shop manual

Jim

[Rerun]

Bill,

You note that the brakes have been bled a couple of times. If I understand correctly, the master cylinder was not replaced. This combination frequently leads to failure of the M/C. When you bleed the brakes, the M/C piston is traveling into an area of the bore where it doesn't normally go. This part of the bore typically is full of rust and dirt. Running the piston there during the bleeding process frequently damages the rubber cups causing the subsequent failure of the M/C. I would say that you need a new master cylinder.

Are we going to see you at Reedsville? I have a used, but serviceable, M/C (drum, no power) that I took off my '64 when I went to the Turner brakes. You're welcome to that if it would help in your troubleshooting.


Jim Bradley
Lewistown PA
'78 Avanti II

[Bill Pressler]

quote:Originally posted by Rerun

Bill,

You note that the brakes have been bled a couple of times. If I understand correctly, the master cylinder was not replaced. This combination frequently leads to failure of the M/C. When you bleed the brakes, the M/C piston is traveling into an area of the bore where it doesn't normally go. This part of the bore typically is full of rust and dirt. Running the piston there during the bleeding process frequently damages the rubber cups causing the subsequent failure of the M/C. I would say that you need a new master cylinder.

Are we going to see you at Reedsville? I have a used, but serviceable, M/C (drum, no power) that I took off my '64 when I went to the Turner brakes. You're welcome to that if it would help in your troubleshooting.


Jim Bradley
Lewistown PA
'78 Avanti II

Jim, you are correct in that the M/C has not been replaced. A few months back I did buy one from SI, anticipating the possible need. Thank you for your generous offer though!

I will be in Reedsville! Joe Kastellac and Ed Davies will be with me. I assume Max is still having his 'bash'? I've always enjoyed that...even though I broke a chair while sitting in it and putting down a beer there a couple years ago!

I know it's a week away, but any long-term forecasts on the weather?

Bill Pressler
Kent, OH
'63 Lark Daytona Skytop R1
'64 Daytona Hardtop

[Rerun]

quote:I know it's a week away, but any long-term forecasts on the weather?

It's always sunny and warm in Reedsville. Actually, the long range forecast is currently calling for partly sunny with highs in the mid-fifties. No mention of the "S" word, at all.

As far as I know, Max has the open house planned for both Friday and Saturday nights, with the band jamming on Friday.

Jim Bradley
Lewistown PA
'78 Avanti II