There is probably a specification for pedal height in the shop manual.  Checking that will give you a clue.  If it is too low, then maybe that bushing is missing, maybe the wrong pushrod is installed, maybe the pushrod hole is too deep in the replacement cylinder, maybe the location that it connects to the pedal has been changed due to a previous owner's bright idea, maybe a pedal return stop is adjusted incorrectly.  If height is good, then it probably is not linkage or actuation related.


Lawrenceville, GA

I can't help going back to the master cylinder. Given all new parts and bled several times there has to be a culprit in the system. The bushing on the end of the push rod may be the reason but over the years I've had brake problems on these systems and it often comes back to not bench bleeding the master cylinder. It seems that bleeding the brakes would fix this but it often doesn't. If the bushing isn't the answer then I would remove the master and bleed it. Just my nickels worth.

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Had a low pedal that drove me nuts on my 56.I made my push rod slightly longer and it helped but did not completely fix the problem. Found this little bushing and it fixed problem. (high brake pedal and hard) I don't remember but I think the bushing was a little wider. Bill

Well, there have been no further comments but this is what must have happened-



The actual bushing had a BASIC PN 2142. If you notice in the ILL, the 2143 BPM is pointing at the rod and the bushing, so the bushing also came installed on the rod. FORD must have dropped the 2142 at some point possibly due to low sales. To get the bushing, one had to buy the rod (2143). Then, the rod went obsolete.

The ILL shown above shows 52/59 but actually it is 55/59. Pre-1955  MC had a different configuration (differences shown in 49/59 MPC FINAL ISSUE). So that explains why the bushing is fairly unknown until this gentleman informed us.

Now, if one installs the bushing (if needed) and then adjusts for  correct pedal height/rod to piston clearance and you still have a soft pedal, you begin a diagnostic routine.

I am supposing this factoid was forgotten as most now go to DUAL RESERVOIR MC's.

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...  i'll be damned ...

THANX monarch!

The deterioration/absence of that bushing will affect both pedal height adjustment and piston travel. It's purpose must have been to protect the piston from direct contact with the push-rod.

BASIC PN 2142 has been removed from the MPC FINAL ISSUE TEXT and also does not show in the ILL.





Talk about a FORGOTTEN FACTOID ...

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Your problem on your 56 Ford is  your master cylinder is not moving enough fluid. When you pump the pedal you are moving more fluid which gives you a higher pedal. I had the same problem. On your mc push rod there should be a plastic cap. This makes the push rod longer and maybe a little wider. Concours Parts sells this part. Most part breakdown pictures do not show this part but theres does. Part Number 2142 in there catalog $8.95    concoursparts.com Hope this helps. It will fix your problem if your cap is missing  Bill

Hey Jeff! I wasn't trying to knock any Ideas. Just that if the System is using Stock Parts it should work properly as designed so a starting Point is the Master Cylinder as far as initial Adjustment and go from there. Personally I think Geo's and mine Problem is related to the integral Valve in the Master. Double Pump gives full Pedal. Shouldn't need to do that.

  

Olcaarmark: It has been mentioned several times in this thread to adjust the push rod longer to gain a taller pedal. I was trying to only point out this adjustment can be over done to where the MC piston does not return all the way home when released which may prevent the MC from getting a full gulp of fluid.  I know from experience how easy it can be to develop tunnel-vision and tune out the obvious when tracking down a problem.   - I wish you well with your winter project, ............JEFF


64F100 57FAIRLANE500

OK. I am coffeed up and my BROWSER seems to be functional ...

The 2lb residual valve is used only if the MC fluid level (actual bowl) is below caliper/wheel cylinder level (this prevents gravity weight of fluid from returning to the MC bowl(s).

The 10lb residual valve is used to control fluid flow back to the MC after brake release so as to not allow cup distortion and possible entering of outside air (see FORD DEARBORN post). It also keeps pressure on the wheel cylinder pistons to make brake reaction quicker upon application. Without the last feature (or defect), the shoes will retract too far and lead to an over travel pedal situation

A RESIDUAL VALVE is usually placed in the MC itself (OEM). The placement on a DUAL RESERVOIR is usually in the outlet port for the drum brake circuit. There seems to be confusion as to OEM design and aftermarket units designed for custom brake systems.

The MC oldcarmark showed is an early GM style (I believe). I do not know where in the system the RV was placed but if the seller can provide source information, a quick GOOGLE should find a breakdown and show the location. There has to be one somewhere and doubling up with an accessory RV will give dire circumstances.

A PROPORTIONING and/or COMBINATION VALVE is not used on a four wheel drum design (although GM did on a few).

These so-called KIT SELLERS (most) are dangerous IMO.

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OK...

Something wrong with my browser. Tried to explain again but guess I am out of here.

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