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View Full Version : Brakes: 1949 2R5 Brake Questions



Robert Crandall
01-13-2017, 08:40 AM
I make an inspection of the condition of each of my relics this time of year - change the oil, grease the fittings, take each wheel off to check the condition of the brakes. This year I found a leaking rear wheel cylinder in my 1949 2R5 truck. All four wheel cylinders were re-sleeved and returned with new kits installed in 2014. Before installing them I checked each one, wiped the parts and coated them with silicone fluid. The bore and the parts were new, so I do not know yet what the problem is. I can guess that the casting may be allowing fluid to leak from the inlet hole into a space between the casting and the sleeve. All brake hydraulic parts, MC, lines, rubber lines, and wheel cylinders were new in 2014.

My questions are:

1. Has anyone found a bolt in replacement for 2R5 rear wheel cylinders?
2. How are brake shoes re-arced or arced to fit the drum diameter?

Thanks.

jackb
01-13-2017, 09:11 AM
I think your problem is (might be) the Dot 5 (silicon) fluid...... Very thin, and unless the sleeving was perfect: leaks. Dot 3 will not as readily get past the rubber. Good luck finding someone to arc your brakes...... any local jobber was gone from here long ago....

nvonada
01-13-2017, 10:09 AM
I might be wrong but I think the arcing was just the friction material, not the changing the shape of the metal. I think they just do it with a belt sander.

Robert Crandall
01-13-2017, 11:08 AM
My former boss, now retired, remembers putting a thicker pad than needed onto the shoes, measuring the inside diameter of each drum, then using a machine to cut the pad to fit the drum.

TWChamp
01-13-2017, 11:17 AM
I used to arc shoes when I worked at the dealership in the 70's, but haven't done it since. I don't worry about arcing the shoes because they are usually a good fit, and the slight difference will wear in with brake use. You should do easy braking especially during the first 1000 miles, and by that time they should be worn to full contact. If the drums have been turned a lot, then you can buy thicker linings to install on the shoes.

Skip Lackie
01-13-2017, 04:48 PM
SI lists rear W/C 521570 for $87.50 each.

PackardV8
01-13-2017, 08:14 PM
Only a bit OT, but one of the reasons younger/new to Studebaker drivers don't like the OEM drum brakes is they've become a lost art. After sixty years of questionable maintenance, substandard materials substituted and uneven adjustment, they can seem dangerous.

However, if one has driven a drum brake car with all new parts, with linings of the proper material, properly ground to match properly turned drums, the whole system bedded in and adjusted correctly, they stop quickly, evenly and smoothly.

As jackb said, good luck finding a shop with the equipment and knowhow. I'd start with a truck repair shop.

jack vines

Robert Crandall
01-14-2017, 09:39 AM
Thanks for your advice. I could not find those WC's at SI back when I had the old ones re-sleeved, and I did not look now. But, as you describe, the part number matches what is shown in the parts manual, and that number does show on SI's website. Unfortunately, the price is now $89.50, but I will buy one. SI sent a $20 discount coupon that will help.

I have learned that you are correct, Mr. Vines. I have an old page that shows drum brake problem scenarios. Having turned larger drums but installing small diameter shoes will make mushy brakes. When I bought this 2R5 in 1980 the brakes had 1/4 inch of pad, the wear surface matched the drum, and the brakes worked perfectly. When I began the revival in 2013, the pads had separated from one or two of the rear shoes, so I bought new shoes for the rear. They are smaller than the original 11 inches, so do not fit the new drums I put on the rear.

The most extreme example that I have seen is on a 1957 Buick that I had (now owned by another SDC member who lets me visit when I can). Powerful engine, AT, and a lot of weight ask a lot of the brakes. Turned drums, standard shoes make the brakes very mushy, and the pads look like a dry lake bed - horrible.

I can ask at a truck shop about that. An article turned up not that long ago about our city's man who maintains our school buses. He mentioned arcing the shoes to the drums being a lost art, but he does it for the buses.

52 Ragtop
01-14-2017, 10:12 PM
Just remember to also check the date codes on the rubber brake hose's! and IF there is NO date code and manufacturer on it, (it will be in the white stripe on the hose) then the hoses you have are at LEAST pre 1977, and should be replaced. Raybestos states on their website that rubber hoses "should" be replaced every 3-5 years.

Jim

Robert Crandall
01-14-2017, 10:52 PM
Thanks. I replaced them in 2014. I did not look at any date code, but I presume they are not horribly old. I presume they were made in China. I rely on the dual master cylinder conversion to reduce my brake failure odds.

52 Ragtop
01-15-2017, 01:24 PM
There are a LOT of NOS brake hoses out there, I would NOT recommend using them. I even seen some "old dates" by some of the vendors at swap meets.

Jim

Robert Crandall
01-15-2017, 06:33 PM
Mine are not NOS. I brought the old ones to my favorite FLAPS. They matched end type and length for me. Certainly China made, very thin diameter compared to the originals, but I believe they are recently made.