Brake issues

[MitchyDu]

Hello, I recently converted my 1981 Z28 from power brakes to manual due to lack of vac from cam. My problem is that after driving for a bit and car warms up my brakes start to lock then after cooling I have little to no brake power. After some research I'm beginning to think my brakes lines may be heating up causing this issue. Any ideas out there? Thanks

[Blownfuel]

Just a thought, but assuming you have headers, how much clearance do you have between the brake lines coming out of the master cylinder / distribution block and the headers? Thinking the lines and fluid might be heating up, causing the fluid to first expand and lock the brakes, then boil leaving vapor bubbles in the lines and no brakes afterwords.

[34_40]

Was there any issue before the change over? As dar as a distance away? As much as possible, I had to make sheet metal panels to deflect the heat from my wires and brake lines on my coupe.

I'm wondering if you've verified the brake pedal push rod is returning completely? And is it in proper adjustment? When you feel the brakes start dragging, remove the reservoir cover and see if the fluid is now overfull. I doubt that it will be. Most times when we hear of dragging brakes, it's the push rod not returning completely or too long and this stops any fluid returning to the reservoir.

By the way, welcome aboard.. good to see you here!

[MitchyDu]

No issues before just poor braking due to lack of vac. Yes I do have headers I have plenty of clearance from master (8")and dis block(4.5") as far as the lines the drivers side lines have about (2.5") and pass side I only have about 1 inch clearance. I had to lengthen push rod and I checked it is returning all the way even have about an eighth of an inch play in pedal. I also installed a proportioning valve under car at rear. Would the 1 inch clearance not be enough on pass side?

[34_40]

1" is very tight! Does it pass by perpendicular? Or does it follow along for awhile.?.?

Like I said earlier, ride around and when the brakes begin to drag, check that the rod isn't holding the master even a little, also raise the cover and see if the fluid level is higher...