I would like to ask advice about a problem that I?m having with my truck. This is my 1953 3/4 ton Dodge M37 weapons carrier that has been sitting idle for the past two years. I finally got around to changing the plugs, charging the batteries and actually got it started. With the rebuilt carbuerator I installed two years ago and now the new plugs it runs pretty well. We changed the oil and did a grease job, Everything on this truck has a grease fitting, and we also topped off all the fluids. When I got to the brakes, I found perhaps two inches of pedal travel and a firm pedal. The master cylinder was full. I thought I was all set. I moved the truck off the hill where it was parked and as it was heading for the side of my house, I hit the brake. The pedal remained high but there were no brakes. The transmission band brake did work, luckily though. I discussed this problem with some of my friends locally and the general consensus was that since the pedal was so hard, the pistons in the master cylinder must be rusted in place. I loosened the output line from the master cylinder and stepped on the pedal. The pedal went to the floor and fluid squirted out of the line. This seemed to eliminate the master cylinder as the culprit. The master cylinder is under the floor. The output line is a six inch line which goes directly into a tee which is mounted on the frame. The two outlets of the tee feed the rear and front brake lines. So now I naturally suspected something common to both the front and rear brakes. It logically seemed like the tee. I decided to disconnect from this tee the line feeding the front brakes to see what would happen. I sprayed both sides of the tee first and hammered on it to set the penetrating oil. To my surprise, the fitting for the front line came right off. I again pressed the brake pedal. It went to the floor. Now it was unclear if hammering on the line dislodged something and could have freed up the brakes or opening the line did it. In any event the master cylinder seemed to be ok and anyway, I broke the line when I disconnected it from the tee. This line is 40 inches long, runs from this tee, up the left frame side and connects via a coupling to another steel line which then connects to a flexible line that goes to the front axle. The coupling is in a place where oil has been splattering for years and so this steel line which goes to the flexible axle line is covered with oil and grease and is in perfect condition. I was at this point pretty confident that either the hammering had dislodged the clog, or the old 40 inch line was plugged, so I replaced the line. I filled the master cylinder and started pumping the brake. The pedal was spongy as to be expected but did come up to about one inch off the floor and hard. So I prepared to bleed the brakes. I had my wife in the truck pumping the pedal, It was one inch from the floor but hard. As she held it down I opened the right rear bleeder as the procedure in the manual says and nothing happened!.I next went to the left front and opened that bleeder as well. Still nothing happened. She still had a pedal. I then opened the flexible line to the left front wheel cylinder. She still had a pedal!. I? m trying to analyse this. I have a pedal but no grakes. I open a bleeder screw anywhere in the system and Istill have a pedal. Could both systems be clogged? I suppose that i could come off the frame tee and replace the line to the rear axle tee and see what happens I don?t want to just start replacing things indiscriminately though but I really don?t know how to troubleshoot this otherwise.. Have you ever seen anything like this before ? Both front and rear seem to be blocked. Is this possible? I?ve never seen it in all the years I?ve ben fixing my own cars. Could brakes on a vehicle get so messed up from just sitting for two years? And if it is two clogs where do you think the most likely place for them might be? Thanks for any advice. Lenny.
- posted
15 years ago