Aftermarket wheel cylinders, had them leak while bleeding the brakes

I found the bleeder screw hiding under the line. I can't seem to get any pressure on the brake side. I bled the inch side and then the brake side and I can't seem to get enough pressure. I have good fluid to the wheel cylinders but only limited pressure and hardly no stop at all....
Also why is it that when I drive and then reverse it feels like brakes are dragging. I inspected the brakes before I found the master cylinders leaking and everything seemed to be good there.
THanks

I found the bleeder screw hiding under the line. I can't seem to get any pressure on the brake side. I bled the inch side and then the brake side and I can't seem to get enough pressure. I have good fluid to the wheel cylinders but only limited pressure and hardly no stop at all....
Also why is it that when I drive and then reverse it feels like brakes are dragging. I inspected the brakes before I found the master cylinders leaking and everything seemed to be good there.
THanks

WHere do you bleed the Clutch master cylinder at? The inching valve or on the block

I use to use an mustard plastic bottle with a rubber hose connected to it. Fill the bottle up with brake fl. and open one bleeder at the wheel cyl. and connect the hose to the bleeder. Squeeze the bottle, forching the brake fl. back up through the system and you will see air coming up into the resviour. Close the bleeder and take off the hose. Do both sides a couple of times and you should have a good brake pedal.

hello all, my 2cents, alway keep spare cap on hand to adapt to radiator pressure tester w/ gauge. makes just the right amount of air. once used shop blow gun and it got away from me and split the hi quality reservuor,what a mess. mike a

Thanks all of you. Very good advices and suggestions.
I opened the wheels, one wheel cyl. leaking too, so I changed it.
Then with a power bleeder, done quickly. This thing is hard to bleed manually.

my best results have been with compressed air also. Bleed the air out with a vac pump or by running a line from the bleed screw back to the M/C. and pump the pedal a few times. Put the cap back on the reservoir and blow about 10psi into it. Pedal should be tight at this point. Stop there! If you open the bleeder again you will lose pressure. I spent a day and a half trying to bleed my first one and it only took two minutes once a old timer showed me that trick.

Glad to see i am not the only one that has lost sleep on this one. I have found only one thing that works. If you attach the brake lines to the master cylinder and then remove the cylinder from the frame and bend the line so the unit is horizontal NOT Vertical. grab a screw driver and pump the little air bubble out. It won't bleed properly in the vertical position. If the reservoir is loosing fluid but you have no visual leaks it might be leaking inside the trucks trans axle. lets us know if any of our suggestions work

bleed the inching valve 1st (even if you didnt touch that side)
then bleed the wheels

i used to get the same issue a lot
never even thought of touching the inching (since i didnt touch it in the 1st place)
but apparently when the pressure is lost on the service side
the inching master loses some sort of equilibrium and you have to reset (bleed) the pressure on that side before moving back to the service side

pssed me off whn i realized what the stupid issue was lol
i tried every trick above and none really work
you might get ehh pressure back but the inching is sloppy (internally) and you wont get a good service brake pedal

try jacking one side up then bleed then got to other side

I have found reverse bleeding to be the best way to bleed most clark brake systems. I do it similar to the way that mrfixit describes, also bouncing the pedal, but not full stroking it, while reverse bleeding helps too.

I take a squirt type oil squirt gun thingy with a piece of hose attached and fill it with brake fluid, hook it to a bleeder and start pumping. It will push the air right up and out to the reservoir. Don't touch the petal. Who ever designed the brakes on those things had to have failed engineering school.

AFTER C500 TRUCKS......MACHINES ARE JUST NOT UP TO SCRATCH ,,JUST MY 2 CENTS

Hello I had this problem many times fill the reservoir screw the cap on open one of the bleed screws then use a very low pressure air line over the small vent hole in cap forcing the fluid out then do same on other wheel. Works every time.