need a bendix brake valve - Page 3
 

need a bendix brake valve

Started by David Anderson, February 04, 2021, 11:00:08 AM

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richard5933

Quote from: David Anderson on February 06, 2021, 03:21:50 PM
I got the 2 front brake cans and new hoses installed, readjusted the slacks back to Eagle book specs.  Installed the new R8 parking brake valve and reinstalled the PP1 valve and knob on the dash.  Checked all my work for leaks and found none

It is easier to release the parking brake, but I do need to give it about 2 more seconds of E6 footbrake  to load the spring brake cans with air and it will release. 

No more audible leak down under the coach with E6 pedal hold down.  I held it down for 120 seconds and lost about 5psi on the gauges. 

Oh and I determined the spring brake cans need to be loaded with air to relax the clevis to get the keeper rods out.  I can then remove the can and slowly dump the air and let the threaded rod extend, then remove the air hose. 

I will block the wheels and do this next week and replace both cans.  I figure after 21 years, why not? 

David

Sounds like progress.

If that 5 psi drop was after the gauge stabilized, you've got a bit more searching to do. It's probably within spec to pass a DOT roadside, but I'd want to get that reduced even further. Hopefully when you get the rears done it will be better.
Richard
1974 GMC P8M4108a-125 Custom Coach "Land Cruiser" (Sold)
1964 GM PD4106-2412 (Former Bus)
1994 Airstream Excella 25-ft w/ 1999 Suburban 2500
Located in beautiful Wisconsin

buswarrior

5 lb loss in 2 minutes is a dream many busnuts will never achieve.

Only if you have a bad(good?)case of the OCD do you need to go after these peepers, it would take a lot of soapy water and looking for small bubbles with horrible payback on the time and effort.

The trick system is beyond/between the parts you have mentioned, additional parts of the plumbing.

Jim Sheppard may be around, but not checking bus boards for a long time, to see if he can help?

Happy coaching!
Buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

chessie4905

Having a pit or lift greatly effects success on this goal. I went through this on mine two winters ago. Amazing how many small leaks I found. Inline check valves, pressure warning sensors were the biggest slow leaking ones. There is a reason the service manual lists rebuild or replace brake system components on a regular basis. 30 to 50 year old coaches with little touched on the systems other than lining, chambers, or brake valves. Leaks are predictable.
GMC h8h 649#028 (4905)
Pennsylvania-central

richard5933

Quote from: buswarrior on February 07, 2021, 06:29:21 AM
5 lb loss in 2 minutes is a dream many busnuts will never achieve....
...Happy coaching!
Buswarrior

It may be a dream, but it's one bus owners should be striving for. Not that we're required to pass DOT roadside inspections, but 2 psi in a minute on a static test and 3 psi in a minute with application of service brakes is the max allowable. If the leak is 5 psi in two minutes on a static test it's really needing some attention. As we all know, these things don't get better on their own, only worse.

I agree that having a pit makes it much easier to hunt down all the leaks. Not having one, I've done it by making it a point to inspect every airline accessible any time anything is opened for any type of work. My current bus was relatively easy, but on our 1964 GM 4106 it did take some effort. Even then, we were able to minimize air leaks to a point where we could easily pass a DOT roadside if we wanted.
Richard
1974 GMC P8M4108a-125 Custom Coach "Land Cruiser" (Sold)
1964 GM PD4106-2412 (Former Bus)
1994 Airstream Excella 25-ft w/ 1999 Suburban 2500
Located in beautiful Wisconsin

6805eagleguy

Pretty sure Jim Shepard checks this board every day? Just look up his profile? Just never posts I guess... his bus is for sale right now on eagles international
1968 Eagle model 05
Series 60 and b500 functioning mid 2020

Located in sunny McCook Nebraska

https://eagles-international.net/forums/viewtopic.php?t=4786&sid=12ebf0fa56a6cbcf3bbaf1886a030a4e

Busted Knuckle

I'm pretty sure Jim is still active on the Eagle's site!
;D  BK  ;D
Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

;D Keep SMILING it makes people wonder what yer up to! ;D (at least thats what momma always told me! ;D)

Jim Eh.

Some dash valves do not actually "pop" out. Later Pete and Volvo trucks are like that. The spring brakes do apply but no traditional "pop" of the valve.

One other suspect to check/replace is any QR1 (quick release) valve in the emergency system (if so equipped). Supply blockage with small leaks down stream of the QR1 could trip a sudden application of the spring brakes.
"Some days it's just not worth chewing through the restraints"
Jim Eh.
1996 MC12
6V92TA / HT741D
Winnipeg, MB.

David Anderson

I finally got back to this project.  The big freeze we had has messed up everything in my schedule. So, I got the big old spring brake cans off and went to Fleetpride and bought two OTR 3036 spring brakes for $281.67, matching the cans removed.

It took most of a day to fit them back on, replumb, and adjust the slacks to within Eagle book specs. 

The book limits travel from 1" to 2".  I set them both at 1.25" rod travel.  I jacked up the wheels and rolled them and no rubbing ;D

I checked for leakdown on a held brake application and lost 2psi pressure at 10 minutes of hold.  I couldn't find any leaks with a soap spray. 

I hope my original problem is solved.  I will find out soon as I'm heading to Oklahoma next week. 

David