M/C disgnosis help?

[///Matt]

So I had 4-wheel power drum. I put a wilwood disc kit on the front, stock M/C and no proportioning valve (yet, I have it). All bled and bedded.

So, the first push of the pedal gets firm response but limited braking occurs. If I very lightly let up and re-apply, braking gets strong/normal.

Is this a check-ball in the M/C kind of thing? Or some other consideration? What do you all think?

The pedal isn’t squishy at all, and he brakes do their job... just a funny quirk in the application.

 

[khryslerkid]

When you let up and apply again you take up any travel in the shoes. Apply the ebrake and see if it still does it.

 

[///Matt]

When you let up and apply again you take up any travel in the shoes. Apply the ebrake and see if it still does it.

I feel you, but with the disc front, hypothetically doing the majority of the brake work, I don’t feel like the rear drums not getting full contact on first press would make the amount of difference I’m getting...

 

[khryslerkid]

I know with my 15/16" bore master cylinder it acts like that. Ill generally hit it twice to have a full pedal. (Manual, drums all the way around, dual MC)

 

[beanhead]

Just a thought here but without the proportioning valve in there, it's maybe not sending enough fluid pressure to the big disc calipers on the first push...you're pumping them up with the second press. The prop valve will limit fluid to rears and let it go up front where it's needed most, with the first press of the pedal. The discs will provide more stopping power but also require more fluid pressure to do so

 

[///Matt]

Just a thought here but without the proportioning valve in there, it's maybe not sending enough fluid pressure to the big disc calipers on the first push...you're pumping them up with the second press. The prop valve will limit fluid to rears and let it go up front where it's needed most, with the first press of the pedal. The discs will provide more stopping power but also require more fluid pressure to do so

I’m inclined to agree... just wanted to see what the braintrust has to say about it, with much more combined experience than I...

 

[beanhead]

...what the braintrust has to say..