I am a GSE mechanic working for the Army in Korea. We have a Clark tug model DT60E which we can't seem to get the brakes to work. The tug was down for 6 months or so while we waited for new front brake calipers to arrive. We installed the new calipers, and proceeded to bleed all 4 calipers. We were unable to get a "hard pedal", and no matter how many times we bled the system the pedal goes all the way to the floor. I changed out the master cylinder with a used one we had, and the same thing. The pedal goes all the way to the floor. I'm stumped as to why we can't get any pedal. There seems to be a good stream of fluid coming out of each caliper when the bleeder is opened. We have gone through 2 quarts of brake fluid trying to get the brakes bled. HELP!! Thanks
Does it have a brake booster? Lacking that, do the brake lines as they're routed have runs that are above the calipers? Air bubbles will hang out up there indefinitely, you have to use a pressure bleeder to get flow enough to push it on through and out the bleeder screws. Just a couple thoughts from the wayback machine.
why did it need calipers same problem or some other reason get or make some plugs to block off the master cylinder bleed that by cracking the plugs open when the air is out it should have very hard pedal if the master is good when you bleed the calipers tapping them with a hammer helps release air bubbles and having a pressure bleeder handy never hurts
Yes, it has what they call a "Hydra-boost" system. I was bleeding the brakes with the engine off. The brake lines run above all four calipers. Our shop does not have a pressure bleeder, so I will check ebay to see if I can find one. Thank you very much for your help!!
Ah, I think that just applies more pressure to the master cylinder, yes? Not like the old vacuum boosters where the brake lines ran in and out of a separate unit? Did the caliper pistons pump out so the pads are tight against the rotors? Lacking a pressure bleeder, have you tried putting a small hose on the bleeder and put the hose in a glass bottle with some clean brake fluid in the bottom? Makes a kind of liquid seal and helps sometimes. There are some check valve auto bleeders out there too as I remember, not sure where you would find them in Korea though...