master cylinder/brake problem
 

I put '48 brakes on my '31 truck using a f 100 master cylinder. I can not get any type of pedal no matter how many times I bleed the system. I put a residual pressure in a few days ago but still no brakes. I replaced the master cylinder last week to no avail.

I have the brake rod going into the master with just about 3 thou shake.

What am I doing wrong or overlooking?

Re: master cylinder/brake problem
 

Make sure the shoes are adjusted. You can't get a pedal with clearance in the shoes. It big dia early Ford brake lines can be hard to blead. The dia makes the velocity of the fluid low and if you have a loop or high spot, air will stay there and it is real hard to get it out. Are the rear brakes cocked at an angle? 32 rear ends mount the rear brakes at a 20 degree angle and the wheel cylinders are not level and won"t blead. I get the car on an incline to level the cylinder so I can blead them. You might try pluging one set of brakes and see if you can get the other end to work.

Re: master cylinder/brake problem
 

I struggled with my hydraulic converted 33 (39 brakes) I tried all the manual bleed ing techniques with my son helping and it didn't work.

I dug out a pressure bleeding kit (marketed in the UK as a Gunson's eezi-bleed - there must be a USA equivalent) and made up a simple adapter to fit it to the 39 master. In 5 minutes the system was completely bled through, great long gobs of air coming out of it.

I'd look for your local equivalent and use that.

Mart.

Re: master cylinder/brake problem
 

Try bleeding at the first junction from the M/C then the next one .

Re: master cylinder/brake problem
 

In have a small Motive pressure bleeder and it worked well on the 39 brakes on my model A.I have used it on different master cylinders. I made an aluminum plate with a rubber sheet seal and clamp it on to the master cyl. with a C clamp. I put ahose barb fitting on it and hook it up.Similar to Mart's I think.

http://www.motiveproducts.com/

John

Re: master cylinder/brake problem
 

Sometimes you need to bench bleed the master cylinder before installing it.

Re: master cylinder/brake problem
 

Last week, I rebuilt all the wheel cyls, master cyl, and replaced all the hoses and the steel lines on the rear axle housing on my '59 Custom 300. I bought a section of 7/32 rubber hose and attached it over each bleeder screw, starting with the furthest one from the master cylinder, and worked my way to the closest one. I bench bled the master cyl before installing it on the car. Total bleed time took less than 10 minutes. I put the hose in a clean jar with about a 1/2 inch of fluid in the jar and gave about 5 strokes on each cylinder, except maybe 8 on the first one and checked the fluid level between each cyl bleed.. Adjusted the shoes and the brakes are good.

Re: master cylinder/brake problem
 

Thanks guys, I ordered a pressure bleeder and will see where that takes me. I did bleed them/c before I put it in and started from the furthest wheel cylinder.