2nd try is a charm. I have successfully installed the 1" bore cylinder. I guess there was just some air in there that wsn't getting out the first go round. It's like a night and day difference. It's both good and bad. It stops better which means I'm going to push it harder. I wish I had done this sooner! That's what I get for listening to the people who supplied the disc brakes!



Here is a picture of the simple holding fixture I made for bench bleeding.







It clamps into a vice and the cylinder mounts almost as it would in the vehicle. I've ovaled the holes so that most Chevy and Ford 2 bolt cylinders should fit. I think Ford 4 bolts may work as well. It works great as a fixture for painting. Just flip it to the other side. I have some longer bolts with 1 1/2" spacers so that the back and bottom of the cylinder can be painted easily. It's a piece of 12 gauge steel welded to a piece of 3/4" square tubing with a .065" wall. I had made patterns for some gussets but it doesn't seem to need it.



Bill,

I don't know if this particular cylinder will help you but you should try a 7/8" bore to see what it does. It will require more pedal travel.


Lawrenceville, GA

We all start out the same.  I can remember my first brake job.  I had NO IDEA one shoe was longer than the other.  It was a complete surprise when I discovered I put two secondaries on one wheel, and the primaries on the other!  I couldn't figure why the car pulled so bad with brand-new Bendix premium shoes.

Ever since then, I paid closer attention to detail.  I had a '64 Tempest that was due for its first set of new shoes.  I noticed the right-rear shoe was perfect, just like it came out of the box, but slightly rusty metal.  I discovered the cylinder had NO hydraulic hole from the inlet to the cylinder bore.  Back then, I bought a new cylinder.  Today, I would drill a simple hole.

Funny, I did a lot of brakes since then, and 'lost sight of' most of them.  A relative will remind me of when I did their brakes while they were in town for a visit (usually on a car that's long gone)...

Charlie, use that 1" bore M/C.  It's new, and it should work perfectly.  Your leg will thank you for using at least 20% less pressure to stop your truck.  My '55 Customline came with a 7/8"-bore manual M/C for 11" X 2-1/2" shoes.

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

I take lots of pictures now. The backwards shoes and adjusters on the wrong side was at least 8 years ago. I have much more experience now!

I'll try reinstalling the cylinder this weekend. Hopefully it was just a fluke. Otherwise, I guess I'll stay with the 1 1/8.


Lawrenceville, GA

Charlie, sounds like your brakes are working just fine.  You should fine-tune your system by adjusting the M/C rod, just so it jiggles.  That will ensure a full retract on the M/C.  Also, pick up your tires and adjust your shoes.  I don't know how new they are, or if you have self-adjusters.

Spinning your wheel by hand, the shoes exert a slight drag.  Adjust all four drum brakes to this "feel".  They should never pull to one side.  As new brakes seat, they go out of adjustment fast because the arc of the shoe is conforming to the arc of your drum.  Before too long, they will mate perfectly and you will gain more surface area on each brake.  Disk brakes don't have an arc, so this only applies to drum brakes.

Disk brakes don't retract either, they relax.  Because they don't retract, there is no brake adjustment.

Charlie, take pictures!  Get a cheap digital camera and store your before/after pics on your computer.  I take 10 pictures of everything.  The ones I don't like, I delete.  So many times, I wished I had taken more pictures at different angles.  Sometimes I refer to a picture for a completely different reason than I took the picture for.  The moment it takes to snap a photo will save you from redoing backwards Pri/Sec shoes, or adjusters.  We've all been there and done that.

I'm glad you got things going again.  To tell the truth, I never use a vise for bench bleeding.  I do it on my drill press table, and back up the M/C against the back post with a 2X4 in between.  I use a long phillips screwdriver, pushing on it with my belt buckle.  My hands are free the whole time.  - Dave

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

I've never measured the pedal travel before but from the original master cylinder, to the replacement original master cylinder, to the Lincoln dual reservoir master cylinder, to the corvette master cylinder, through 4 wheel drums, and disc/drum, the pedal has felt the same. I even had the only shop I trust check out the drum brakes after I did them just to make sure I did everything right - it was my first time. I had shoes backwards and adjusters on the wrong side. Anyway, when I got it back the pedal felt the same. So I have to believe that 2 1/4 is is in the ball park for what it needs. I can lock the front wheels and it will not pull. I can adjust my proportioning valve so that I can lock all 4 wheels and it does not pull so I have to believe everything is adjusted and functioning properly. Assuming a 4:1 pedal ratio, it works out to about 9/16" at the mc. Maybe it's semantics but I've never driven a car where the brake pedal hardly moved.



Oh, and yes I see the benefits of bench bleeding. I'm going to make a tool for it, though. I don't like what the vise did to my fresh paint on the mc.







The new one did have a little more play before the push rod actually pushed on the piston. It may have been about 1/16" difference at the cylinder. I didn't adjust it because I wanted to make sure it would work before changing the setting. Perhaps I should have adjusted it.


Lawrenceville, GA

Charlie, you are a very thorough man (and a good one).  I told you 30 strokes because I wanted to make sure no bubbles were coming out when you were done.  Bottom line: You can see the advantage in bench bleeding vs wasting fifteen strokes of brake fluid & bubbles through your brake lines.  If you saw both sides bubbling, that proves both sides are working just fine (they work independent of each other).  So, there's no need to disassemble.  Seeing those bubbles is another advantage of bench bleeding.

Your brake pedal calculations are good except for one thing.  When your shoes or pads are adjusted correctly, your brake pedal will hardly move.  The piston diameter won't mean much at all if the pistons hardly move.  Your travel will be at the top of your pedal.  When you get your M/C installed, bled, and you adjust your shoes, you'll see.

- Dave

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

I got a chance to perform a bench bleed this evening. I did 30 strokes. Both reservoirs bubbled for about half. When it stopped bubbling, I could see the fluid rise in the reservoir as a result of the fluid being displaced by the piston. So I guess this means that it is working. I'm not able to try to install it tonight so I put the cap on and plugged the ports.

I didn't take it apart. It has a funky circlip and I don't think I will be able to get it out with the tools I have available without damaging the cylinder or myself.



I measured my pedal travel. It requires about 2 1/4" travel with the 1 1/8" bore cylinder. I have about 7 1/2" until the pedal hits the floor.

Am I correct thinking that my new pedal travel should be equal to current pedal travel times the area of the current piston divided by the area of the new piston? PTn = PTc ( Acp / Anp) and so it should require about 2 7/8" with the 1" piston.



Is it possible that the master cylinder is bottoming out even though the pedal goes all the way to the floor?


Lawrenceville, GA

I'll give bench bleeding a whirl today.


Lawrenceville, GA

Bench bleeding has very little to do with bleeding your system, it's just the beginning.  If you don't bleed the system after bench bleeding the M/C, you WILL have air in your lines, guaranteed.  You can bench bleed with the M/C installed, but it is much easier to level (and cleaner) when done on the bench.

Regarding all this discussion; bench bleeding is easier to do, than to talk about it.

Rebuild your M/C if you think it needs it, then bench bleed it.  Same goes for new Master Cylinders.  Here's a good web site explaining 'bench bleeding'.  There isn't much to it:

http://www.misterfixit.com/brakbld1.htm

This is a method using old brake lines.  Notice the tubes are below liquid level so air has only one way to escape.  I use full strokes when bench bleeding.

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

Charlie: Glen is correct. I bought a Master for an 80 Malibu some time ago. It came with bench bleeding instructions. If you take your rebuilt one apart, the guarantee if any, is gone! I don't remember exactly how I followed the bench bleeding up, but I managed to loosely connect the lines to it, with the resivour topped up, put a rag under it and while using the pedal to apply some pressure & with fluid at the connections, I closed them. I didn't even have to bleed the system after..

Paul