'30 30U Brake Question

[hursst]

I blew a rear brake cylinder a few weeks ago in my 30U with fluid all over the floor and everything. I've had the car only 3 months now. Upon taking the whole mess apart for a rebuild, I noticed that the brake shoes were installed with the long shoe pads towards the front of the car, while the short ones were towards the rear. Everything I've ever known is that the short shoe pad goes to the front, not the rear. Is there something different about the 30U, or, as I'm assuming, the previous owner(s) installed the brake shoes incorrectly? I have now had both rear cylinders and all 4 brake shoes professionally rebuilt and they are ready to install. I figured I'd ask just to be 100% sure.

While I'm asking, does anyone still use the stock brake cylinder bleeder valves (the ones with a screw-in valve that has another screw-in bolt to seal up the valve), or has everyone switched to zerk fittings? I'd like to run the originals, since I like EVERYTHING stock or orginal, but I hear they can be annoying when bleeding them. However, I have a specialized bleeder pump that has many different rubber fittings, so it will fit the originals or zerks just fine. What are some of the opinions out there? Any comments are appreciated.

[ply33]

It is my understanding that on a Lockheed brake setup that only the front shoe is self-energizing, so to get equal braking effort for both shoes the rear shoe has a longer lining. At least that is how I put things together with the long shoe on the rear.

I made an adapter that screws into the bleeder that has a barbed hose setup. So, yes, you aren't the only one using the original style bleeders. With silicone brake fluid, the system stays maintenance free for long enough that the minor issue of installing an adapter to bleed the wheel is a very minor issue.

I have, however, swapped most of my grease fittings to the modern style as the old style (last used in 1933) are a pain and I do chassis lubrication on a pretty frequent basis.

[Guest martylum]

Just finished looking at a brake assembly blowup for U-30U in the early Plymouth parts book and it looks like the longer shoe faces the front. Your owners manual would have the same blowup. It been a long time since I installed new shoes and cylinders on my30 Desoto but the brakes work great. Better measure your drums with a drum gage to see how worn they are. If they are more than .060 over be prepared for fade in heavy braking in the mountains. Mine are .090 over and did expand causing fade on the downhill runs on a Tour in New Hampshire. They seem to work fine in regular usage and are almost impossible to find for a wire wheel car.

There is an adapter for these old style grease fittings (Model A Ford vendors) but it doesn't work very well so I put in a modern fitting for each lube but keep the originals on for show. I loaded my system with DOT 5 in the early 90s and am still using with no service or parts replacement.

Martin Lum

30 DeSoto

[hursst]

Guys, thanks for the advice. I tried going with the original valves, but I had trouble with the one-man bleeding unit, so I switched to modern fittings for now. Turns out the brake bleeder is no good anymore anyway, so I have to start all over with a new bleeder kit tomorrow. I think I'll stick with the modern fittings until I can find an adapter or other solution that works well.

As far as the brake shoe directions, I saw the diagram in my owners manual, but I didn't see any reference to which direction was the front of the car. If the diagram is representative of the driver's side, then the long shoe is in the rear. Marty, does your parts guide specify which direction is the front of the car when viewing that diagram? I'll check the brake drums out, that's a good idea. I'm only going to do light driving for now, so I'm not too concerned.

My car was greased before I bought it a few months ago, so I haven't gotten to the grease fittings yet. I'll keep both of your opinons in mind when I get arond to greasing.

Thanks!!!

[Guest martylum]

The blowup identifies the longer lining shoe as "front half". I would interpret this as being to the front on the installation. The shoe with the shorter lining is labeled-"rear half".

Auto mechanics were trained by an apprenticeship system in those days-there were no shop manuals in 1930 for Chryslers-at least. You should have the 80+ page Owners Manual for tips on mechanical work and specs.

My 30 Desoto Owners Manual says nothing about front vs rear shoes so the blowups there are different than in the larger Plymouth Master Parts Book.

You need to read between the lines sometimes.

My early Desoto parts book has the same illustration and same labeling-front vs rear

Martin Lum

[hursst]

Thanks again. I decided to go with the "longer" shoe in the front and the "shorter" shoe in the rear, as Marty described. If that's what the manual is saying, plus that's the way I found them when I took them apart, I think I'll go with that. I got a new one-man bleeder and I was able to get it to a moderately hard pedal. I still have some more bleeding to do, but it's drivable around the neighborhood for now. I think I need to replace the brake fluid reservoir, just as the previous owner was trying to do. I think it is slowly seeping fluid out of the bottom due to corrosion. I think that's why I keep getting some air in the brake lines no matter how much I bleed them. Thanks again for the advice; with your help, it's roadworthy again.