The Stovebolt Site Forums The Parking Lot Big Bolts Big truck brakes - a bit off-topic

Guys, I hate to get off the Stovebolt topic here, but I need some help with my family's '39 American LaFrance fire truck. It has Timken brake drums on front, with a comma-shaped adjuster for each shoe near the wheel cylinder at the top of the brake assembly. Does anyone have a clue what the proper adjustment for these might be?

Today I destroyed a small fridge in the garage after the truck got away from me. It felt like I had pedal pressure, but when I shifted it into gear there were no brakes. The front brakes have been disonnected for a long time, but I recently made new lines and replaced the wheel cylinders. Before now, the rears worked fine. There are no leaks in the system, and I bled everything after my repairs. Any suggestions on how to get this behemoth working properly are appreciated. (BTW, it has a 350 in the engine bay, so this is kinda-GM related...)

If I felt unsafe driving that monster with only the rear brakes, no brakes was even worse!

Thanks, TooMany. I have become a bit worried that it has lower adjusters, too, and I'm positive that I have the tops backed off too far.

Also, Freightliner does own ALF these days. Their museum page says to contact local dealers about legacy parts and info. That is on the list, but I figured someone on here would have worked on some similar brakes at some point - they look like off-the-shelf parts, rather than specially made for ALF.

DOes this truck have air over hydraulic system?

No air, but it has a vacuum booster that is bigger than the engines in some import trucks... It also has the rather bizzare situation of the single-cylinder master being located 3/4 of the way to the rear axle.

Are the wheel cylinders at the front and rear of the set-up with the adjusters at the top and bottom(just off from directly top and bottom)?
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Also found this for you
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http://www.wardlafrance.com/engineer.htm

The wheel cylinders are at the top, between the shoes. There is an adjuster on each shoe about 1/3 of the way down the shoe, that is shaped like a comma. I don't know if there are adjusters at the lower pivots, I'm considering pulling a drum back off to find out.

Ward-LaFrance almost certainly bought brake assemblies off the shelf from Bendix or Wagner.

I have quite a bit of reference material on old truck brakes, but it doesn't tell me what brake assembly W-LF used. If you can get a fairly good picture of the brake assembly and post it or e-mail it to me, I can probably identify it and scan a set of adjustment instructions for you.

Joe

I appreciate all the help, but I think I need to clear up a few things. It is an American LaFrance, not a Ward LaFrance. Different company. Also, the brakes (at least the drums) are marked Timken. I had no idea that they had ever made brake parts, but their name is cast into the drums.

At this point, I have a decent idea where the problem lies (but keep the ideas coming ). The only problem is, I'm probably not going to have much time to work on it until July.

OK. Same answer. Post a decent photo of the brake assembly, and I'll try to ID it for you.

Joe

I might be able to get one in about a week.

the correct adjustment is to let the shoes lightly drag the drum. timkin made complete rear differential assemblies,including brakes for many years, mostly for g.m.. if you remove the rear drums i highly recommend coating the moving parts with antiseize, being careful to not slop any on the shoes. i would also be real suspect of that master cylinder, and would attempt bleeding the brakes to see how much fluid comes out, and the color of it. remember brake fluid attracts moisture.

Except for the front lines the brakes were rebuilt before we got the truck. The hoses for the fronts were unavailable, so they were disconnected. A mechanic friend had a friend who was able to braze our old hose ends onto new lines, and pressure tested them to over 300psi. Now I just have to get the shoes adjusted right...

Ummm...manual brake systems typically develop up to 600psi under hard braking conditions. I would consider 1500psi to be the minimum test pressure for hoses and fittings.

There are people building custom brake hoses. If a local clutch & brake supply can't refer you to one, let me know and I'll give you the number of a place out here in Sacramento.

Joe

I don't remember exactly what they were tested to, but it was done by someone who does brake and clutch lines. No signs of any fluid leaks.