1953 Dodge M37 3/4ton weapons carrier brake problems

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Oct 6, 6:34 am, snipped-for-privacy@yahoo.com wrote:

I spent 35 years in the Canadian Army and replaced many wheel cylinders on 3/4 tons. Its odd that all four would be seized but I would pull the wheels and have a look.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Back in the 1970s I traded my 1967 Ford pickup truck for a big 1954 Ford ex farm truck.I think the big truck was rated as a one ton truck, it had an eight feet square bed behind the cab.It was originally an old farm truck from Illinois.One morning I got in the big truck to go to work, the brake pedal went all the way to the floor, one of the brake lines had rusted out.
To be on the safe side concerning old vehicles it is always best to install new or rebuilt brakes and new brake lines. cuhulin
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Oct 6, 6:34 am, snipped-for-privacy@yahoo.com wrote:

does it have a proportioning valve or something similar where the lines come together?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I remember in Can Tho in 1964 a small U.S.Army trailer being pulled behind a truck to the Motor Pool shop.The brakes on the trailer were locked up, the wheels on the trailer were not turning at all. cuhulin
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@yahoo.com wrote:

SNIP

> to be blocked. Is this possible? I’ve never seen it in all the years I’ve ben

Well it sounds like there is a problem on both ends. The problem with the bleeders could be that they are blocked by crud. Take one out completely and see what you get. Water may have settled into the wheel cylinders and rusted them solid as well. I would plan on either replacing or rebuilding the wheel cylinders, then flush the system with new fluid.
--
Steve W.
Near Cooperstown, New York
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@yahoo.com wrote:

You are probably going to end up replacing all the brake lines in the end. After you get pressure in them they will start to pop. Usually it will be the lowest point in the brake line that is where water will collect on the inside and it will rot from the inside out. The wheel cylinders for the same reason are likely to need replacement because of pitting.
     But to bleed the brakes I would start back at the beginning. It sounds like you ran the master cylinder out of fluid when you broke that one section. So to get the air out of MC loosen the fitting where the brake lines starts and bleed the air out of that. Once the MC is working again the downstream bleeding should start to work again.
    My guess is that the brakes were working before. When you get around to removing the wheels you may find the brake shoes soaked in axle lube and that is why the brakes weren't stopping the truck.
-jim

----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups ---= - Total Privacy via Encryption =---
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 6 Oct 2008 03:34:30 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

The rubber lines can swell internally and cause problems like this. I would start at the master cylinder and break the connections down the line until you get to the point where no fluid flows through the broken connection.
Steve B.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Thanks guys I'm getting back into it today. I'll let you know. Lenny
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@yahoo.com wrote:

By any chance is there a steel ball in the bore underneath each bleeder screw? Look down one of the bores with a strong light. I think I remember a long time ago seeing a type of bleed screw that used a steel ball, that could get frozen in the bore with age and rust. I don't remember where or if it was even the brakes.
If you find this, you might try loosening all four screws at the same time, just one or two turns. Then hit the brake pedal hard but quick, and see if one of them pops. You might need to bleed some of that added air through a downstream coupling, to get this to work.
--Dave
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.