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Topic: Park brake valve (Read 699 times) previous topic - next topic

Park brake valve

Today the park brake valve stuck in the off position, but later was operable at a lower pressure. Is this common, or a sign of impending failure? I have a 130 psi governor and the valve  does not leak. Air system is tight and only losses 10 psi per week. A shot of lube into one of the ports maybe? Isn't so much the $, but I am time challenged.

Oh yeah unloader also appearantly stuck today for a while at 110 psi and I can't find a can of corrosion x as suggested by craneman I think.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: Park brake valve

Reply #1 –
I took mine apart and rebuilt it.  Link below to the thread, which has photos of the disassembled valve.  Also link to Bendix PP-1 manual.

Bendix PP-1 Repair Kit

BENDIX PP-1-2-5-8-RD-3 PUSH-PULL VALVES MANUAL Pdf Download.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Park brake valve

Reply #2 –
Chuck i seen your excellent post during my search, that's why I mentioned my low leakage rate. Just wondering about the fact that it got stuck, and just maybe needed a shot of suitable lubricant, or other best practice, or it just the nature of the beast. Thanks for your reply.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: Park brake valve

Reply #3 –
When I have had that problem I only had to hold the valve in for a longer period of time and it would release. Seems to fix itself after that. I have only replaced the valve for leaking around the seal. I do carry a spare in the crane as down time is critical.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Park brake valve

Reply #4 –
If your valve is not leaking, the O-rings are probably still OK.  You can see in the photos of the valve I rebuilt, there was a lot of dried up white grease inside.  I don't think it would hurt anything to shoot a little lube of some kind into the air ports and see if it frees up the pull rod.  However, if time permits, taking the valve apart and cleaning it out would be a better solution.  Then you could reassemble it with something like Super Lube, which is a superior synthetic grease for all O-ring sealed applications.

Super Lube 3 oz. Tube Synthetic Grease with Syncolon PTFE-21030 - The Home Depot
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"