Brakes: 2R5 Rear Brake Cylinders

[Rerun]

Working on a '51 2R5. It needs rear wheel cylinders. When I check part listings for this truck, they show a 1-3/8" bore cylinder. What I have is a 7/8" bore. The Wagner casting # is FD8374. Any ideas as to what I have, or what replacement part(s) I should be looking for?

[StudeRich]

I don't know WHAT Catalog you are looking in, certainly NOT a Studebaker Parts Catalog.

The ONLY R Series Truck that uses a 1 3/8" Rear Cyl. uses TWO of them per Wheel, and they are single Piston dead end type!

It is a 681068 for 2R-14 to 17 to 8E-25, 28 & 35.

I sell the 521570 7/8" Cyl. for the rear of 2R5's.

[jclary]

Working on a '51 2R5. It needs rear wheel cylinders. When I check part listings for this truck, they show a 1-3/8" bore cylinder. What I have is a 7/8" bore. The Wagner casting # is FD8374. Any ideas as to what I have, or what replacement part(s) I should be looking for?

[ATTACH=CONFIG]77818[/ATTACH] [ATTACH=CONFIG]77819[/ATTACH]

I don't have a solution for your question, but I want to commend you for the way you took and posted the picture of the wheel cylinder off of the vehicle. It has been several years now, but a while back I needed to service my rear wheel cylinders. My truck is a 1955 E-5 and the rear cylinders mount with the staggered holes as shown in your picture. When my local parts store couldn't come up with new cylinders, I went to some Studebaker parts vendors and eBay to find one that would fit. However, most of the folks seem to show the wrong view of the cylinder and those that showed the mounting holes were not staggered like the ones used on the rear of our half ton Studebaker trucks.

I finally found the right cylinder, but I've never forgotten how frustrating it was trying to find one advertised with the important mounting configuration properly displayed.

[StudeRich]

Yeah John that was WHEN Parts Stores still sold them, and Wagner USA still made them.

Now, our Studebaker Wholesaler is the ONLY one, that can sell them to Studebaker Vendor Retailers.

All you get from any others is wrong Parts, as Jim found out.

[Studebakercenteroforegon]

Working on a '51 2R5. It needs rear wheel cylinders. When I check part listings for this truck, they show a 1-3/8" bore cylinder. What I have is a 7/8" bore. The Wagner casting # is FD8374. Any ideas as to what I have, or what replacement part(s) I should be looking for?

[ATTACH=CONFIG]77818[/ATTACH] [ATTACH=CONFIG]77819[/ATTACH]

Let me guess...you think RockAuto has reliable, correct listings for Studebaker parts? I see they do claim that. 1951 2R5 uses a 1.375” diameter rear wheel cylinder! Wrong! Think of the time you would have saved contacting a knowledgeable Studebaker parts vendor instead.

[Skip Lackie]

This issue came up recently on the Stude Truck Forum, where someone with a newly-purchased late-50s 1/2-ton Stude truck tried to find wheel cylinders. The Rock Auto site showed Dorman 19236 and 19238 as fitting. Those numbers are only correct for the 1963-64 8E series trucks, which used the Lark brakes. Twenty or 25 years ago, the auto parts companies hired idiots to digitize their old analog parts catalogs, and those people consolidated listings into a single part number that does not fit most of the vehicles listed. I have some old Wagner and Bendix paper catalogs, and they show that some of the correct truck wheel cylinders were already NLA 30 years ago.

[Rerun]

Let me preface my comments by saying that I certainly appreciate our faithful Studebaker parts vendors, who I have patronized for many years. Though I've owned and repaired Studebakers for 50 years, I've not worked on a truck until recently. This 2R5 belongs to a neighbor. His father bought it new, and there is really only sentimental value involved. It had not run in decades, and has been outside under a tarp. My neighbor has severe macular degeneration, and can no longer do most repairs. I (perhaps foolishly) volunteered to take a look at the truck. Fast forward... It now runs quite well. Now we need to be able to stop it. We're doing a resurrection, not a restoration, and "driveway brakes" is the objective. The first item is these cylinders. Very simple, nothing special, cylinders. I guess that I was floored to see prices approaching $100. Yes, I understand all the reasons. But, I would hate to scuttle this low budget project. I would not be at all surprised to find a compatible 7/8" bore cylinder that would work if I re-used the pistons, or drilled another hole in the backing plate, or attached the brake line at a different angle, etc. Yes it's the CASO approach! Would I feel guilty about not buying these cylinders from one of our regular vendors? Probably not in this case.

[jclary]

Thanks for further clarification. Armed with the additional info, I went back and reviewed your picture of the wheel cylinder I am assuming you removed from the truck. It really doesn't look all that bad. My suggestion would be to buy rebuild kits, a good hone, and a gallon of DOT 3 brake fluid. Then, chuck that cylinder in a vise, heat up the bleeder, use a penetrating oil and gently try to remove it without breaking it. Then, hone the hell out of the cylinder(using DOT 3 as your cutting fluid) until it has a clean bore. Rebuild the cylinder and you should be good for quite a while.

Ideally, new or replacement cylinders would be best, but these cylinders can take a good bit of honing and still function well. The bleeders are undersized and are easy to break. If you can, replace them and use never seize on the threads. The last thing I would do is to mess with the engineered geometry of the brakes as designed.

[Rerun]

Thanks for further clarification. Armed with the additional info, I went back and reviewed your picture of the wheel cylinder I am assuming you removed from the truck. It really doesn't look all that bad. My suggestion would be to buy rebuild kits, a good hone, and a gallon of DOT 3 brake fluid. Then, chuck that cylinder in a vise, heat up the bleeder, use a penetrating oil and gently try to remove it without breaking it. Then, hone the hell out of the cylinder(using DOT 3 as your cutting fluid) until it has a clean bore. Rebuild the cylinder and you should be good for quite a while.

Ideally, new or replacement cylinders would be best, but these cylinders can take a good bit of honing and still function well. The bleeders are undersized and are easy to break. If you can, replace them and use never seize on the threads. The last thing I would do is to mess with the engineered geometry of the brakes as designed.

John,
As you were responding, i was in the garage doing exactly what you suggested. Must be that "great minds think alike" thing. I was able to remove the 1/4" bleeder intact, and gave the cylinder a heavy honing. It looks pretty good, and a $5 kit should give us what we need. On to the next wheel! Thanks to all for your input. After decades in the dirt, another Studebaker will roll again.

[thunderations]

Another solution if the cylinder were pitted and not rebuildable would be to have it sleeved. Another fairly expensive fix, but would get the job done.

[jackb]

If you go with the re-Honed cylinder approach.... my humble advise would be to stay with Dot 3 fluid. Dot 5 will find a way behind the cups if not excellent

[Rerun]

If you go with the re-Honed cylinder approach.... my humble advise would be to stay with Dot 3 fluid. Dot 5 will find a way behind the cups if not excellent

I agree. As much as I prefer to use DOT5, I would only use it in a system with all new components.

[Frank DuVal]

Not my experience. I have used DOT 5 on all older cars over the last 35+ years, many with re-honed wheel and/or master cylinders. Never an issue.

[Mrs K Corbin]

Rock auto does sell a 1" or 7/8 bore cylinder, however the bolt holes are not staggered. I have a couple on my CASO truck, and they work.

[Rerun]

Rock auto does sell a 1" or 7/8 bore cylinder, however the bolt holes are not staggered. I have a couple on my CASO truck, and they work.

Do you happen to have the part numbers?