Air Brake Leak - need part number / info

CindyandJohn · July 27, 2012, 11:20:54 AM

Hi All,

I found the source of a pretty significant air leak and need help identifying this and what I need to do to repair it. I attached these two pictures. I found on Bendix that it is a pilot relay? Not sure that this is exactly it. The leak is in the bottom where the snap ring is. I read that this might be a replaceable part? hopefully... They mention something about a replacement inlet/exhaust valve cartridge replacement. Search for that - couldn't find it. So what I need to know is what is this? what part numbers should I be even thinking it is? and does anyone know where to get such a replacement valve cartridge?

As always any and all help and input is appreciated.

Thanks,
John

1989 Eagle 15 - 6V92T

belfert · July 27, 2012, 12:48:58 PM

Is this at the front or rear? If at the rear it may not be the valve leaking. Your Eagle probably has spring brakes. See if it still leaks with the parking brakes released. If the leak stops one of your chambers is probably bad.

CindyandJohn · July 28, 2012, 07:52:54 AM

Hi All,

duplicating post from other board -

This is on the front of the bus. I was hoping not to have to take it all off - but it sounds like I might have to. The view of the snap ring is looking up fromthe bottom. It has only 4 ports - the two on the face in the picture - one is blocked off on one side - the other side has a large line and the smaller lines coming off it. The bottom portion with the snap ring is what is leaking. I trust the PO made only positive installations as it is Wyn Silver from Central Florida Bus. I saw the ones on eBay and I am thinking this is the R14 as well. Is this supposed to match one in the back? If so I suppose I should review that and make sure they match and purchase the same. If it is necessary to replace one - should I consider replacing them both to make sure they match up? How should I determine the proper "crack pressure"? I'm bad and don't have a manual... I am certain the valve is leaking... I loose air in couple days. It used to hold for a week or more. I was soapy water spraying lines to try and find a leak and when I got to this it was blowing big bubbles! Parking brake was on - otherwise I wouldn't be sitting under there!

Thanks for the input guys!

luvrbus · July 28, 2012, 08:06:38 AM

That is a anti-compound valve Eagle used different models call Ed at Jefferson in OKC with the serial number of your model 15 he will probably the valve or the kits it does look like a R-14 and they use 3 or 4 lbs of crack pressure

good luck

Oonrahnjay · July 28, 2012, 08:49:28 AM

Quote from: luvrbus on July 28, 2012, 08:06:38 AMThat is a anti-compound valve Eagle used different models call Ed at Jefferson in OKC with the serial number of your model 15 he will probably the valve or the kits it does look like a R-14 and they use 3 or 4 lbs of crack pressure
good luck

Yeah, but John says that it's under the front of the bus? Unless his parking canisters are on the front axle (not likely) or there is some "interesting" relay mechanism on the rear axle (also not likely), that seems quite unusual to me. When I rebuilt my brake system, I made the "delivery" lines from the R-14 to the rear cans less than 24 inches long. It seems to me that air line runs from an R-14 under the front of the bus would make for lots of delay and tricky balance in the system.

As I mentioned in the FaceBook group, if I had a valve (assuming for the minute that we're talking about an R-14 but that doesn't really matter) that was acting up, I'd buy a factory "remanufactured" valve. If it's leaking from one point, it's likely that there's wear or corrosion or other problems elsewhere in the valve. If an owner replaces a seal or a valve body or a cover, that's OK for that small part but what about the rest of the unit? If the R-14 is being used for it's main purpose (i.e, acting as a relay for the main rear brakes and also an activating unit and anti-compounding feature for the parking brakes), it's a complicated component with carefully balanced functions across the different parts of the valve. If I had one that was showing a problem in *any* point, I'd go for a fully remanufactured unit (or a new one) -- brakes are too important not to be sure that everything is working right. (And problems with anti-compounding can sneak up on you -- if there's a leaking or stuck valve in the anti-compounding function of an R-14, you could run it for years and never be aware of the problem -- but IF and WHEN you need that function, that's not when you want to find out that it doesn't work.)

luvrbus · July 28, 2012, 09:46:57 AM

The model 15 Eagle has always had that valve at the front with the dual air system like he has on his 15

Eagle has a totally different set up than most buses and John has a 45 ft Eagle so he needs a manual or call ED and get it right Eagle changed at certain serial numbers

The anti compound valve on a Eagle works with the service brakes also why I have no idea lol the Eagle came with spring brakes since the 1980's

Oonrahnjay · July 28, 2012, 10:51:53 AM

Quote from: luvrbus on July 28, 2012, 09:46:57 AMThe model 15 Eagle has always had that valve at the front with the dual air system like he has on his 15

Eagle has a totally different set up than most buses and John has a 45 ft Eagle so he needs a manual or call ED and get it right Eagle changed at certain serial numbers

The anti compound valve on a Eagle works with the service brakes also why I have no idea lol the Eagle came with spring brakes since the 1980's

That's good information to know and it will help John. Thanks. Maybe when John gets his hands on a air system diagram he'll post it so some of us who may be interested will be able to see HTH it works.

luvrbus · July 28, 2012, 11:21:53 AM

That is where it get touchy Bruce with out the serial number of his bus some model 10 had the same setup Ed will tell him and he doesn't have to buy from Jefferson they will give the info no matter who you buy from

Oonrahnjay · July 29, 2012, 12:35:17 PM

Quote from: luvrbus on July 28, 2012, 11:21:53 AMThat is where it get touchy Bruce with out the serial number of his bus some model 10 had the same setup Ed will tell him and he doesn't have to buy from Jefferson they will give the info no matter who you buy from

I'm sorry, Clifford, I wasn't clear. Getting the parts and fixing the bus right is one thing and the system diagram is another and I kinda ran them together. Here's what I meant to say:

John, follow Clifford's advice about getting the right parts from Ed based on the serial number and getting them installed correctly -- it's really necessary that you get the right parts because they vary in some of their details, especially interior parts; nobody's better at that than Ed. Once you've done that, get a copy of the air system diagram that was published to match your bus, study it until you understand why and how all the parts work together, and then post a copy of it so that we can all have a look at how this system is designed.

Hope that's clear. BH NC

CindyandJohn · August 08, 2012, 05:27:20 AM

Thank you for all the great advice. I will call Ed about it and order form them. I do want to get the manual for my bus - anyone have a source? I have heard of someone selling the CD's - please let me know. I will post info once I get it together.