The Stovebolt Site Forums The Parking Lot Big Bolts 66 C60 need help adjusting an bleeding brakes

hey guys I'm getting confused on which direction to go when I'm adjusting my brakes can somebody tell me the correct way on which side driver or passenger side front and rear to adjust the night so I can adjust the brake and also I need to know the proper way to get this thing to bleed because me and my buddy have tried to bleed the brakes all day yesterday I have brand new hydro vac system brand new lines brand new wheel cylinders brand new master cylinder.....

HELP PLEASE

Howdie 67dump. I am here with the same problem. I have a 1960 Viking c60 2.5 ton, and replaced the master brake cylinder last week (the old one had been leaking fluid down onto the inside floor pan). So, I got the new brake cylinder installed (after having to drill and tap a hole for the hydrovac line), and I added brake fluid. I did ensure that all three lines were full of fluid before screwing the lines into the brake cylinder, and then I added fluid to the resevior. I then pumped the brakes some, but did not have time to do any bleeding at the wheels, and thought that it may self-bleed if I just leave it for a few days. I came back this week and found the brakes rock-solid, and almost no pedal travel. I cranked up the engine to make sure that there was a vacuum for the hydrovac, but when I hit the brakes I get almost no pedal travel, and no brakes. Its like stomping my foot on a cinderbloc.....no pedal travel. I then unscrewed the front bleeder screws and had someone hit the brakes, but no fluid comes out, and the brake pedal only moves down about an inch or so.

When I remove the master brake cylinder top, I notice that I get fluid pumping back into the cylinder, and more pedal travel, but the pedal quickly stiffens up. Still no fluid going to the front brakes.

Any idea as to what I am doing wrong??????

Is it possible that I need to bleed the hydrovac first?????

67dump.....Im guessing that you bleed the front brakes first, and the passenger first (further away), then the driver's side. Let me know what you found out......maybe between the two of us we can finally get brakes again.

I am not familiar with either 1960 or 1966 trucks, but let me make a couple of comments that may or may not help. Some people advise bench bleeding a new master cylinder before installation. You can search in this forum for previous threads on that topic. Otherwise, in bleeding a system with a hydrovac, you must start with the hydrovac itself. I am familiar with only the first and second series of these devices and they have two bleeding ports. One of these is near the body of the valve and is done first, the second is near the outlet and is done second. Then you go to the wheel cylinders, start with the one that is on the longest line (usually a rear) and go progressively on shorter lines to finish with the cylinder on the shortest line.

To dwightviking1960; I do not understand what you mean by having to drill and tap the new master cylinder. The hydrovac is in series with the brake system, meaning the line from the master cylinder goes into hydrovac, and then the line from the hydrovac goes to your brake lines. There should be no drilling or tapping, unless I am demonstrating my ignorance of later types.

To 66dump; without punctuation in your post I find it difficult to follow your thoughts or understand your question(s). "adjust the night"?? I hope, however, that my above comments are constructive.

Kent

Kent......thanks for the useful information. Now I know to first bleed at the hydrovac, and work onward to the wheels.

Regarding drilling and tapping an extra hole in the master brake cylinder, the old one that I took off has a brake line that screws into the front of the master brake cylinder, and one screwing into the side (that had access to the lower portion of the resevior). The one going into the side is probably the return line coming back from the hydrovac. I guess that suppliers no longer drill/tap this extra hole as there are too few people ordering this type.

So, I am hoping that by doing the proper bleeding procedure, I will be able to get fluid to the wheel cylinders, and the rock-hard brake pedal will start working. I really dont want to tear into the hydrovac and rebuild it (although a great learning experience, I suppose).

Bench bleeding.......I will have to find the right threads and go read-up on the proper method. However, the MBCylinder is now installed, and I do believe that starting the bleeding technique at the hydrovac should work. Fingers crossed.

Thanks again.
dwight

I know this sounds redundant,but did you replace the rubber lines? They collapse,from the inside,and restrict flow. In some cases,the harder you press,the harder the pedal becomes. They don't lose pressure,either. you can come back weeks later, and the brake pedal is still hard!!