More brake questions, learning as I go.

As a glutton for punishment, I’m working on a mid-50s vintage car brakes. Three of the four connections on the pipes to the reservoir have slight leaks - both on the reservoir, one on the bracket. This causes the brakes to release when the reservoir pressure drops below the brake pipe pressure. The pipe assemblies have threaded connections to the typical bolted flanges on both ends, not welded assemblies, which is where the leaks are. They kinda look like some sort of compression fitting.

What the heck am I looking at and is this repairable? Or do I need to replace the pipes with welded assemblies? I haven’t found any fittings online that look similar these, everything I find is weld neck.

I didn’t have my phone on me so no pictures.

Those are probably "Dresser" fittings, which were popular in those days. Also used in certain types of plumbing and commercial process piping, as well oilfield piping.

https://dresserutility.com/dresser-pipeline-solutions/

They may now be prohibited from unrestricted AAR freight car interchange.

Howard P.

The fittings sound like unions, whicn are often needed to connect a tank (or other device) to a pipe system.

Many unions have gaskets, which could develop leaks with age.

First thing to try is to open one up and replace the gasket (if one is found).

These sound like WABCOSEAL fittings, which use a rubber ring similar to a compression fitting around the pipe and an o-ring like rubber seal between the flange and the boss on the reservoir. The design was improved on and sold under the name GRIPSEAL. The older design can be identified by a collar with hex flats, while the improved design has a internally threaded nut designed to be tightened by a pipe wrench. A pic or two would help.

I’ll see if I can get someone to snap a couple pics, I won’t be back at it until next Saturday so it may be a bit until I can post some images.

Thanks to your hints, the connectors are definitely not Wabcotite. By memory, they look very much like Grip-Seal couplings. Those were last offered by Jaeco Fluid Systems though Grip-Seal is no longer on their website. I did find pdf files on them in a folder on Jaeco’s domain but not linked to any pages so not active. I’ll contact them to see if they still offer them in case that’s what I’ve got.

If I strike out on these fittings, I may need to get new pipes fabricated.

[edit] here’s the Jaeco pdf. The fitting looks like the 1/4” to 1” IPS coupling.
http://jaecofs.com/pdf/JaecoGripSeal_SizingChart.pdf

Pictures would definitely be helpful. Do you have the typical AAR 2-bolt flange connection to the manifold, and there is an additional hex nut like a compression fitting that is over the pipe, and that nut is screwing into a male thread on the flange fitting? If so, yes it definitely sounds like a WABCOSEAL. Does a soapsuds test show the leak coming from the annulus between the nut and the pipe itself? If so, try tightening that nut to further compress the rubber sealing ferrule. I think the replacement rubber parts still exist from WABTEC if needed.

Jeff,
I think you and MT4351 are right on the WABCOSEAL. The whole system is WABCO. However, they’re not leaking between the pipe and the threaded sleeve (annulus). They appear to be leaking from the exposed threads. There’s good amount of surface rust so I didn’t want to really crank on them in case I break something without having any replacement parts. I asked some of the guys for pics and I’ll post them if they remember. Otherwise, I’ll need to wait until Saturday and do that myself.

Ya fix one thing and then something new starts leaking a week or two later. It’s been soaped so many times it’s a wonder it isn’t buried in suds when it rains.

A picture would be worth a thousand words here!

There were some fittings where what appears to be a compression nut and rubber bushing is actually a strain relief, and the flange is a regular threaded one. The strain relief is to reduce the chances of the pipe thread breaking off when the pipe flexes.

If the leak appears to be coming from the exposed male pipe threads you just might have hairline break in the pipe at that point, which would be an unpleasant problem.

Here's the fitting. What is it and is it replaceable?

Not Dresser fittings. Looks very much like WABCOSEAL (WABCOTITE may be a similar arrangement). That looks pretty crusty. You might want to consider new flanged fittings and a new piece of pipe. Another method would be a hose assembly from Strato, with the right flanges on each end.

Howard P.

WABCOSEAL, see attached. You will need items 3 and 4 (for 1/2" pipe), which are probably still available from WABCo (in its current iteration). The parts catalogue doesn't list the material, nor does the piece number record. However, these are both probably "rubber goods" (WABCo's term), particularly item 3, and given the age they most likely aren't the white dot formula, which means they will stick to the metal upon disassembly.

If you install new pipes, make sure they have bends like the original (i.e. no pipe elbows). Soaking the threads in turpentine or ATF for a month is advisable before attempting disassembly.

MT4351 - Many thanks for the chart.

Thinking ahead and considering my luck on this car, the fitting body and nut might be be too corroded to be reused. Is there an alternative that can be used or would I be looking at having new lines fabricated?

Soak the threads repeatedly over about a month in a penetrant (turpentine, ATF, Cyclo Breakaway, Kroil, LPS1, but not WD-40, which is junk). If you can undo the cap screws in the flanges at each end (pipe bracket and reservoir), grip the hex nut holding the pipe in a vise and use an open end wrench on the flats of the body (it's what they there for). Work things back and forth, gradually unscrewing, rather than all at once. Tapping on the fitting's body with a hammer (but don't beat on it) while trying to loosen might help breaking things loose. If you use an impact wrench (on the bolts), pull the trigger in very short, brief bursts, pausing at least five seconds between burst otherwise the threads will overheat, gall, seize up, and you'll never get things apart.

These rubber seal pipe fittings have not been allowed in new construction for more than 40 years. They were impossible to keep from leaking. I doubt that you will have much luck finding replacement parts. I do not know how much you are concerned with historical accuracy. I ran a number of rebuild programs where we replaced all the rubber seal fittings with socked welded fittings. New construction is usually built with butt welded fittings, but this is done with a lot of tooling and fixtures. With socket weld fittings they can be fitted up on the car, tacked in place, then finish welded on the bench with either stick or MIG.

WD 40 isn't junk, it's just a water displacer rather than a penetrating oil. Hence the WD in the name..... it's actually pretty good at doing it's job. Unfortunately, with my Pete Best sense of timing, i invested heavily in WD 39. Oh, well.