m37 brakes

[Matthew Ziegler]

A while back I installed the helitool disc brakes on my m37 along with the chevy master cylinder specified on his website. it was working fine until recently, I changed a brake hose on the steering knuckle and a caliper after bleeder screw issues. after this the front brakes were dragging, I re bled them a couple of times and eventually found a bad fitting letting in air. re bled the system, now the pedal is as hard as a rock and the brakes aren't that great. also I was looking at a friend's m37 he has a 1 inch or so block between the brake pedal and bottom of the cab floor, is this stock? my m37 and a friend's m43 don't have it? I appreciate any input, thanks in advance, Matt

[windage]

check that hose

rubber brake hoses have been known to come apart in the lining and if you have a "flap" of rubber in there, it can act like a check valve..just a thought

[Desoto61]

I tend to wonder if you got a bad caliper in your replacement. One the brakes started dragging after you replaced the caliper, though you didn't say which brake(s) were dragging.

Two you mention a fitting letting air in, but that would only happen when you release the peddle, which should then get spongy vice harder.

A hard peddle usually means the brakes aren't releasing properly, which could be something the flap thing, though I would suspect in an axle hose since if it were only one caliper it would only affect that wheel and the rest of the system would still work, so it would get stiffer but not as solid as you seem to make out.

Another option for a brakes that aren't releasing is usually a MC problem, specifically if the return port has gotten clogged or the piston isn't returning completely then the fluid pressure can't release back to the MC.

Do you have disks at all four wheels or just two?

[Tom Petroff]

The blocks don't belong there.
TGP

[Matthew Ziegler]

brakes

I got it fixed, two things I learned to look out for, a lot of the currently made chevy master cylinders are Chinese junk and are pretty much worthless out of the box, after some phone calls I was able to get a bendix unit ( much better quality) also I think the pedal does require some kind of stop, mine was coming up too far through the floor, it was actually a little awkward to get my foot on, it's now at a more comfortable height and I simply adjusted the push rod to the master cylinder to compensate. Also I drained and flushed the system and refilled it with dot 3 fluid.I notices the lid to the master cylinder said use dot 3 only and didn't want to take a chance, also the military fluid seems to bubble in the system and is much more time consuming to bleed. It's working well, locks up the front tires when needed and stops predictably during normal driving.