Brakes feel like they don't engage until almost to the floor

[Nodnarb76]

Now that I have my LS Swap done, I am ready to turn my attention to an area that has been needing some attention for a while, my brakes.

4 years ago when I bought my 87 R20 Suburban, I replaced the booster and master cylinder because the brakes felt a little soft. When my friend replaced the booster, he had a hard time getting the pedal right and ever since then the brakes would only engage once the pedal is almost to the floor. Last week I started to revisit my brakes and started by replacing the master cylinder. I still have the same issue of the brakes engaging almost at the end of pedal travel. Is there an adjustment on the booster? If so, how do I do it?

[Nick_R_23]

If the pushrod is engaging the master cylinder correctly and the pedal is just soft until the end of the travel, there are three reasons of why this will happen:

1. You either have the wrong bore size master cylinder, where the piston is too small and will only have pushed enough fluid when it is at the end of it's travel.

2. Master cylinder is damaged and is allowing fluid to push past the piston/seals as the pedal is pressed, losing pressure internally.

3. There is still air in the system, either the master cylinder was not bled out properly (bench bled) before it was installed, or there is air still in the lines.'

If the pushrod does not engage the master cylinder until the pedal is nearing the end of it's travel, you likely have the wrong booster installed.

[homemade87]

If it an 87 most likely one of those step bore master cylinders . Those are extremely hard to bleed all of the air out . It took me about 2 hrs to get mine bleed . I would pump it , tilt it pump it , shake it , let it set , bleed ,bleed ,bleed some more . I could not believe how long and how much air came out of it even at the end. There is a special bleed tool/process that is use for these step bores but I do not have one .

Take it off and take your time and re bleed . Don,t know if is your problem but will not cost you anything to try , but possibly fix your problem . It took care of mine .